The Disease (Timeline)

Learn from the news about the structure of SARS-CoV-2, how the virus causes Covid-19 disease, who is most vulnerable and what doctors are learning.

Click on dark blue words or terms to see their meaning in the glossary.

STAT: What we knew and don’t know about long Covid
(March 23, 2021)

• “About 1 in 10 people who had Covid but were never admitted to a hospital report they experience bewildering brain fog, shortness of breath, muscle weakness, or crushing fatigue in the months after the first signs of their initial illness. Some see no end in sight; others seem to recover.”
• Two theories for the cause:
  1. The virus or part of it might be hiding in the body.
  2. The immune system suffered some damage.

Science: Many people who die of COVID-19 have the virus in their hearts
(March 17, 2021)

Science: How do you treat coronavirus? Here are physicians’ best strategies
(March 16, 2021)

PopSci: A comprehensive guide to coronavirus symptoms
(March 10, 2021)

BBC: Covid blood protein offers clues for treatments
(March 10, 2021)

• Cytokine GM-CSF “was found to be nearly 10 times higher in patients who went on to die from the virus”.

Harvard: Symptoms, spread and other essential information about coronavirus and COVID-19
(March 9, 2021)

nature: Pregnancy and COVID: what the data say
(March 9, 2021)

• “Pregnant women fare worse than others, although the risks to the fetus are slight.”

Modern Healthcare: Coronavirus deranges the immune system in complex and deadly ways
(March 4, 2021)

nature: US health agency will invest $1 billion to investigate ‘long COVID’
(March 4, 2021)

SciAm: COVID Variants May Arise in People with Compromised Immune Systems
(February 23, 2021)

nature: How ‘killer’ T cells could boost COVID immunity in face of new variants
(February 12, 2021)

nature: What’s the risk of dying from a fast-spreading COVID-19 variant?
(February 5, 2021)

SciAm: Pregnant during Pandemic: The Bump That No One Saw
(February 4, 2021)

STAT: A viral mystery: Can one infection prevent another?
(January 31, 2021)

SciAm: COVID Can Cause Forgetfulness, Psychosis, Mania or a Stutter
(January 21, 2021)

(January 19, 2021)

• “In contrast to cytokine storms, which tend to cause systemic, short-duration problems, autoantibodies are thought to result in targeted, longer-term damage.”

STAT: What we now know — and don’t know — about the coronavirus variants
(January 19, 2021

nature: Rogue antibodies could be driving severe COVID-19
(January 19, 2021)

nature: COVID’s toll on smell and taste: what scientists do and don’t know
(January 14, 2021)

STAT: How — and why — coronaviruses mutate (VIDEO)
(January 14, 2021)

BBC: Past Covid-19 infection may provide ‘months of immunity’
(January 14, 2021)

Science: Saliva could hold clues to how sick you will get from COVID-19
(January 13, 2021)

STAT: Most patients hospitalized for Covid-19 still have symptoms six months later, China study finds (January 8, 2021)

SciAm: The Immune Havoc of COVID-19
(January 1, 2021)

STAT: As a doctor in the Covid-19 era, I’ve learned that judging patients’ decisions comes easier than it should (December 31, 2020)

STAT: Explanations for ‘long Covid’ remain elusive. For now, believing patients and treating symptoms is the best doctors can do (December 29, 2020)

SciAm: The Problem of ‘Long Haul’ COVID (December 28, 2020)

SciAm: The U.K. Coronavirus Mutation Is Worrying but Not Terrifying
(December 24, 2020)

Science: U.K. variant puts spotlight on immunocompromised patients’ role in the COVID-19 pandemic (December 23, 2020)

STAT: A ‘duty to warn’: An ER doctor, shaped by war and hardship, chronicles the searing realities of Covid-19 (December 21, 2020)

STAT: The looming questions scientists need to answer about the new variant of the coronavirus (December 21, 2020)

Science: Mutant coronavirus in the United Kingdom sets off alarms, but its importance remains unclear (December 20, 2020)

STAT: As the pandemic rages, demoralization deflates health care workers
(December 19, 2020)

Science: Neanderthal gene found in many people may open cells to coronavirus and increase COVID-19 severity (December 18, 2020)

nature: How COVID-19 is changing the cold and flu season (December 15, 2020)

Science: COVID-19 is 10 times deadlier for people with Down syndrome, raising calls for early vaccination (December 15, 2020)

STAT: The coronavirus at 1: A year into the pandemic, what scientists know about how it spreads, infects, and sickens (December 14, 2020)

SciAm: What Science Has Learned about the Coronavirus One Year On (December 11, 2020)

STAT: New cancer patients — especially Black people — are more susceptible to severe Covid-19 infections (December 10, 2020)

nature: How kids’ immune systems can evade COVID (December 10, 2020)

STAT: New data, dashboard provide information on Covid-19 hospital capacity
(December 10, 2020)

nature: Could COVID delirium bring on dementia? (December 2, 2020)

nature: Coronaviruses closely related to the pandemic virus discovered in Japan and Cambodia (November 23, 2020)

nature: Can dogs smell COVID? Here’s what the science says (November 23, 2020)

• “Around the world, canines are being trained to detect the whiff of COVID-19 infections. Dog trainers are claiming extraordinary results.”

SciAm: Coronavirus News Roundup, November 14-November 20
(November 20, 2020)

STAT: Delirium could signal Covid-19 infection in older adults, study finds
(November 19, 2020)

STAT: ‘People are going to die’: Hospitals in half the states are facing a massive staffing shortage as Covid-19 surges (November 19, 2020)

SciAm: Mysteries of COVID Smell Loss Finally Yield Some Answers
(November 18, 2020)

nature: What if tropical diseases had as much attention as COVID?
(November 17, 2020)

MPT: Here’s Why COVID-19 Mortality Has Dropped (November 17, 2020)

The Atlantic: ‘No One Is Listening to Us’ (November 13, 2020)

• News from the front lines at Rhode Island Hospital and in hospitals throughout the US.

SciAm: An Emerging Tool for COVID Times: The Portable MRI
(November 12, 2020)

STAT: Developmental disorders top the medical conditions that heighten the risk of dying from Covid-19 (November 11, 2020)

• Reasons why developmental disorders and intellectual disabilities may increase risk:
  • They are often associated with multiple chronic conditions.
  • Individuals are more likely to work in essential services and live in group homes.

NM: Endothelial cells resistant to SARS-CoV-2 infection (November 10, 2020)

Reuters: Common cold antibodies hold clues to COVID-19 behavior; lung scans speed COVID-19 diagnosis in stroke patients (November 6, 2020)

NPR: Clots, Strokes And Rashes. Is COVID-19 A Disease Of The Blood Vessels?
(November 5, 2020)

STAT: New research points to potential link between pollution levels and Covid-19 death risk (November 4, 2020)

NYT: Death Rates Have Dropped for Seriously Ill Covid Patients (October 29, 2020)

nature: Neanderthal DNA highlights complexity of COVID risk factors
(October 26, 2020)

SciAm: What We Know So Far about How COVID Affects the Nervous System
(October 22, 2020)

• “Some studies show evidence that SARS-CoV-2 can get into nerve cells and the brain. The question remains as to whether it does so routinely or only in the most severe cases.”

BBC: Long Covid: Who is more likely to get it? (October 21, 2020)

PopSci: Meet the disease detectives fighting to understand COVID-19
(October 20, 2020)

NatGeo: Invasion and Response (October 14, 2020)

• A graphic guide to how SARS-CoV-2 enters and attacks the human body.

SciAm: Neanderthal DNA May Be COVID Risk (October 10, 2020)

NYT: The Coronavirus Unveiled (October 9, 2020)

• An excellent article that illustrates the virus atom by atom and explains what we know about its structure.

SciAm: COVID-19 Is Now the Third Leading Cause of Death in the U.S. (October 8, 2020)

SWI: Swiss researchers create artificial lung to study Covid-19 blood clots
(October 7, 2020)

BI: A day-by-day breakdown of coronavirus symptoms shows how COVID-19 goes from bad to worse (October 2, 2020)

SciAm: One in Seven Dire COVID Cases May Result from a Faulty Immune Response
(September 30, 2020)

AP: Mild to severe: Immune system holds clues to virus reaction (September 30, 2020)

SciAm: Could Exposure to the Common Cold Reduce the Severity of COVID-19 Infection?
(September 28, 2020)

Science: Hidden immune weakness found in 14% of gravely ill COVID-19 patients
(September 24, 2020)

Science: An ‘uncoordinated’ immune response may explain why COVID-19 strikes some hard, particularly the elderly (September 16, 2020)

Science: As evidence builds that COVID-19 can damage the heart, doctors are racing to understand it (September 15, 2020)

nature: How COVID-19 can damage the brain (September 15, 2020)

nature: The lasting misery of coronavirus long-haulers (September 14, 2020)

DW: Predicting how severe your COVID-19 infection will be (AUDIO) (September 14, 2020)

NatGeo: Private autopsies are on the rise during the COVID-19 pandemic
(September 10, 2020)

SciAm: Coronavirus: How It Infects Us and How We Might Stop It (September 9, 2020)

Harvard: COVID-19 and Blood Clots (September 9, 2020)

• Patients with severe COVID-19 with high levels of blood clotting protein factor V are at a higher risk for dangerous blood clots.

nature: The coronavirus is mutating — does it matter? (September 8, 2020)

Science: Why COVID-19 is more deadly in people with obesity—even if they’re young
(September 8, 2020)

FT: What bats can teach us about developing immunity to Covid-19 (September 8, 2020)

SciAm: Coronavirus and the Flu: A Looming Double Threat (September 6, 2020)

STAT: ‘Carnage’ in a lab dish shows how the coronavirus may damage the heart
(September 4, 2020)

nature: Coronavirus reinfections: three questions scientists are asking (September 4, 2020)

NYT: Where Is America’s Groundbreaking Covid-19 Research? (September 1, 2020)

• Here is a comparison of Covid-19 research in the US and in Britain.

SciAm: COVID-19 Can Wreck Your Heart, Even if You Haven’t Had Any Symptoms
(August 31, 2020)

nature: The coronavirus is most deadly if you are older and male — new data reveal the risks (August 28, 2020)

STAT: My severe Covid-19: It felt like dying in solitary confinement (August 28, 2020)

PopSci: What makes a patient asymptomatic to COVID-19? (August 27, 2020)

nature: Coronavirus research updates: Sex differences in the COVID-19 immune response might drive men’s high risk (August 26, 2020)

Science: The coronavirus may shut down the immune system’s vital classrooms
(August 25, 2020)

SciAm: Why Do Some People Weather Coronavirus Infection Unscathed? (August 25, 2020)

STAT: Four scenarios on how we might develop immunity to Covid-19 (August 25, 2020)

Science: Some people can get the pandemic virus twice, a study suggests. That is no reason to panic (August 24, 2020)

NYT: Researchers reported the first confirmed case of coronavirus reinfection, suggesting that immunity in some people might last only a few months. (August 24, 2020)

STAT: Is Covid-19 growing less lethal? The infection fatality rate says ‘no’ (August 24, 2020)

The Economist: How viruses shape the world (Requires free registration.) (August 21, 2020)

SciAm: Why Some People Get Terribly Sick from COVID-19 (August 20, 2020)

• One reason the elderly are vulnerable: With increased age:
  • “B cells, which make antibodies, and T cells, some of which directly kill infected cells and some of which alert the B cells, are no longer produced in large quantities in the bone marrow and thymus gland, respectively. Eventually, production nearly grinds to a halt.”
  • “Both the stem and arms of the Y-shaped antibody molecule become less flexible. This limits the body’s ability to modify them to match an unfamiliar invader.”
  • T cells “lose a lot of the variety of receptors that allow them to respond to diverse pathogens, and they may lack the vigor to rapidly multiply in response to infection”.
  • One has more underlying diseases involving low-grade inflammation.
• Men are more vulnerable because:
  • Estrogen hormones (in women) strengthen the immune system, but androgen hormones (in men) have the opposite effect. (This may be the result of evolution, where women pass molecules for immunity to their offspring.)
  • Men tend to develop compromising conditions (heart disease, hypertension, diabetes) earlier in life than women do.
  • There are more genes on the X chromosome involved with the immune system and their expression is greater.
  • (Perhaps) there are gender differences in “attitude and behavior” regarding protection and healthy habits.
• Genetic variation between individuals:
  • In genes involved in the expression of cytokines and ACE2.
  • (Perhaps) in genes determining blood type.
  • (Perhaps) a single-gene variation involving resistance to Covid-19, as in the story of “one discovered in 1996 called CCR5 delta 32, which confers resistance to HIV”.
• “High-risk conditions”:
  • Are “associated with chronic low-grade inflammation” that compromises the immune system.
    • In obesity, fat cells can produce more interleukin-6 and other substances causing inflammation.
  • Cause an upregulation (heightened expression) of ACE2.
• Societal effect on underprivileged populations:
  • Employment with more physical contacts and less possibility of working remotely.
  • Higher risk of infection through “high-density, lower-income neighborhoods” and with a higher proportion in prisons and homeless shelters.
  • A higher rate of high-risk underlying disease.
  • “Structural inequities” such as reduced access to healthiest food, green spaces, cleaner air.
  • Less access to medical care or Covid-19 test sites.
  • “Discrimination within the health care system”.
  • Physical effects of psychological stress from discrimination.
  • “Race doesn’t put you at higher risk. Racism puts you at higher risk” – Dr. Camara Phyllis Jones

STAT: Seven months later, what we know about Covid-19 — and the pressing questions that remain (August 17, 2020)

nature: COVID-19 poses a riddle for the immune system (August 17, 2020)

STAT: Going viral: What Covid-19-related loss of smell reveals about how the mind works
(August 14, 2020)

• “At least half or more of patients worldwide with confirmed Covid-19 were diagnosed with full-blown anosmia“, the loss of smell.

STAT: Long after the fire of a Covid-19 infection, mental and neurological effects can still smolder (August 12, 2020)

nature: Track post-COVID sickness, not just cases and deaths (August 11, 2020)

STAT: How a Zoom forum is changing the way ICU doctors treat desperately ill Covid-19 patients (August 6, 2020)

• Currently there is only one last resort after ventilation fails for a Covid-19 patient. The procedure is called ECMO (for extracorporeal membrane oxygenation). This operates as an artificial lung outside the body that supplies oxygen to and removes carbon dioxide from the blood. Blood is removed from a large vein (the femoral vein) in the groin and returns oxygenated blood to the body through the right jugular vein. When this procedure was first used for Covid-19 in China, the success rate was very low (around 20%). Gradually the success rate has been rising worldwide as doctors are learning from each other’s experience with the procedure in adjusting all possible parameters, and in particular through the Zoom teleconferencing application. One great challenge has been that blood thinners are needed to prevent Covid-19 forming blood clots throughout the body, particularly dangerous as it can cause strokes, but that blood when thin is likely to bleed where tubes are inserted into the body. The success rate for ECMO is now estimated at 55% to 60% and is likely to keep rising.

NYT: The Covid Drug Wars That Pitted Doctor vs. Doctor (August 5, 2020)

• An article that gives examples of the kinds of tensions that arise between doctors when they disagree about the proper approach in treating a particular patient.

Science: Why pregnant women face special risks from COVID-19 (August 4, 2020)

• “Fetal infections later in pregnancy appear to be rare, and experts are cautiously optimistic that the coronavirus won’t warp early fetal development.”
• But “pregnancy does appear to make women’s bodies more vulnerable to severe COVID-19” due to a “pregnant women’s uniquely adjusted immune systems” and because “the lungs and the cardiovascular system—are already stressed in pregnancy”.
• According to a Swedish study, pregnant women, and those just having given birth, are six times more likely to be admitted to an ICU.
• A pregnant woman’s “entire immune system is geared toward making sure not to create any antifetal immune response. The mother has to compromise her own immune defense in order to preserve the baby’s health.” – Yale immunologist Akiko Iwasaki
• “As the uterus grows there is less and less room for the lungs. That’s why pregnant women often feel short of breath.”
• Pregnant women require up to 50% more oxygen in order to also supply the fetus.
• A pregnant woman’s blood is more likely to clot “thought to be due to their need to quickly staunch bleeding after delivering a baby”.

NYT: Scientists Uncover Biological Signatures of the Worst Covid-19 Cases (August 4, 2020)

Science: From ‘brain fog’ to heart damage, COVID-19’s lingering problems alarm scientists
(July 31, 2020)

STAT: The nursing science behind nurses as coronavirus hospital heroes (Opinion)
(July 30, 2020)

STAT: Covid-19 infections leave an impact on the heart, raising concerns about lasting damage (July 27, 2020)

• In one study, 78% of those who “recovered” still had issues that involve the heart two months later. The average age of the patients was 49 and two thirds of them recovered at home.
• Another study found a high viral load of SARS-CoV-2 in the heart in 24 out of 39 autopsies.

SciAm: Genes May Influence COVID-19 Risk, New Studies Hint (July 21, 2020)

CNN: I can’t shake Covid-19: Warnings from young survivors still suffering (July 19, 2020)

STAT: Multisystem inflammatory syndrome in children related to Covid-19 isn’t the mystery it’s made out to be (Opinion) (July 16, 2020)

SciAm: Second Coronavirus Strain May Be More Infectious—but Some Scientists Are Skeptical (July 16, 2020)

• “Researchers question whether a mutated viral strain that infected more cells in a lab dish is necessarily more transmissible among humans.”

GLP: Who is most vulnerable by age and race to die from COVID-19? (July 16, 2020)

Science: The pandemic virus is slowly mutating. But is it getting more dangerous?
(July 14, 2020)

SciAm: Babies’ Mysterious Resilience to Coronavirus Intrigues Scientists
(July 14, 2020)

PopSci: One in three young people could face serious symptoms from coronavirus
(July 13, 2020)

CNN: How coronavirus affects the entire body (July 11, 2020)

The Verge: Doctors are better at treating COVID-19 patients now than they were in March
(July 8, 2020)

• “But they still don’t have good tools to help people who aren’t severely ill.”

NatGeo: How scientists know COVID-19 is way deadlier than the flu (July 2, 2020)

nature: A race to determine what drives COVID-19 severity (June 29, 2020)

• From an analysis of 94 genomes, there is scientific evidence that the spillover from animals to humans did not happen at the Wuhan wet market as was initially thought. Two variants of the SARS-CoV-2 virus were discovered, giving evidence that the spillover happened elsewhere, as some of the earliest patients were not linked to that market. The variants differed in only two nucleotides and do not appear to have led to any differences in Covid-19 severity.
• The same researchers found evidence that the most severe cases of Covid-19 are associated with lymphocytopenia, a low number of lymphocytes in the blood and suggest that this is caused by the cytokine storm known to occur in such patients.

STAT: Researchers report nearly 300 cases of inflammatory syndrome tied to Covid-19 in kids (June 29, 2020)

STAT: It’s not just the lungs: The Covid-19 virus attacks like no other ‘respiratory’ infection
(VIDEO) (June 26, 2020)

STAT: When Covid-19 hits the brain, it can cause strokes, psychosis and a dementia-like syndrome, new survey shows (June 25, 2020)

nature: Mounting clues suggest the coronavirus might trigger diabetes (June 24, 2020)

• “Evidence from tissue studies and some people with COVID-19 shows that the virus damages insulin-producing cells.”
• ACE2 enzymes are found on cells in “many organs involved in controlling blood sugar”.
• A global diabetes database has recently been established to keep track of non-diabetic Covid-19 patients with high blood sugar levels.

SciAm: Special coverage: Inside the Coronavirus (June 23, 2020)

• An animated visualization of the latest information learned on how SARS-CoV-2 infects cells and replicates.

nature: Mini organs reveal how the coronavirus ravages the body (June 22, 2020)

• “The virus can damage lung, liver and kidney tissue grown in the lab, which might explain some severe COVID-19 complications in people.”

SciAm: A Visual Guide to the SARS-CoV-2 Coronavirus (July 2020 ed.)
(June 17, 2020)

• New knowledge explained graphically of how the spike is cleaved after the viral particle binds to the ACE2 receptor, revealing a protein mechanism that opens the cell membrane so that the RNA can be released into the host cell.

nature: More than one billion people face increased risk of severe COVID-19
(June 17, 2020)

• “More than 20% of the world’s population has at least one underlying condition that raises the risk of severe” Covid-19 disease.
• “Nearly 350 million people — some of whom do not have underlying conditions — would require hospitalization if infected.”

nature: Coronavirus research updates: Swiss survey finds that children are less susceptible to infection (June 16, 2020)

• In a study at Geneva University Hospitals testing antibodies in 2700 people 5 years of age and older, fewer children than adults were found to have been infected. The researchers suggest that the reason is that children are less susceptible to infection.

Science: HIV and TB increase death risk from COVID-19, study finds—but not by much
(June 15, 2020)

• An analysis of 12,987 patients in South Africa found that HIV patients were at a 2.75 times higher risk and tuberculosis patients were at a 2.58 times higher risk of death from Covid-19.
• This is much lower than the risks involved with other conditions:
  • Risk for patients between 50 and 60 years of age is 10 times higher than a patient less than 40 years of age.
  • Risk for patients with diabetes is 4 to 13 times higher.

SciAm: Why COVID-19 Makes People Lose Their Sense of Smell (June 13, 2020)

• The ACE2 and TMPRSS2 receptors are highly expressed in the olfactory sensory epithelium (OSE) that contains sensory neurons that transmit the sense of smell to the brain. SARS-CoV-2 doesn’t appear to attack these neurons directly, but rather other cells within the OSE. This either prevents air from reaching the olfactory clefts, which are responsible for olfaction (the sense of smell), or causes a dysfunction in the neurons indirectly through processes such as those involved in inflammation or metabolism.

The Straits Times: Popular blood pressure medicines do not put patients at greater Covid-19 risk, new study finds (June 13, 2020)

• New research gives further evidence that taking ACE inhibitors and ARBs does not increase risk of severe Covid-19 disease compared to other treatments for high blood pressure.

nature: Why children avoid the worst coronavirus complications might lie in their arteries
(June 11, 2020)

• “Evidence is mounting that healthy blood vessels protect children from serious effects of COVID-19, such as stroke.”
• According to one large survey, children 17 and under in the US make up 22% of the population but less than 2% of COVID-19 cases. Of 2,572 infected children surveyed, 5.7% were hospitalized and three died.
• A team headed by Dr. Frank Ruschitzka at the University Hospital Zurich in Switzerland found widespread inflammation of endothelial cells in patients with severe Covid-19, cells that are known to affect the clotting properties of the blood and suggested that damage to these cells are the cause of clotting throughout the body. (Read more about the discovery of the role of endothelial cells in Covid-19 in the June 2 article in Science, the April 20 article in The Lancet and the May 8 article in Nature.)
• Paul Monagle, a pediatric hematologist at the Melbourne Children’s Campus hypothesizes that severe Covid-19 is rare in children because of their healthy endothelial cells. He will perform two experiments involving plasma from children and adults to test his hypothesis.

nature: Virus conscripts a pair of human proteins to invade cells (June 11, 2020)

• Researchers in Britain have shown that neuropilin-1 (NRP1), a human protein, can bind to the spike protein of SARS-CoV-2, helping the virus bind to a cell.
• They have also shown that an antibody binding to NRP1 prevents infection of cells in vitro (in the laboratory).
• In mice, NPR1 helped the virus reach the central nervous system.
• It is suggested that treatment drugs designed to block the binding of NRP1 onto the spike could be effective.

STAT: ‘Flying blind’: Doctors race to understand what Covid-19 means for people with HIV
(June 10, 2020)

• Science knows very little about the effects of HIV on the risk of Covid-19 symptoms, complications and death. Two studies to date had too few participants to arrive at conclusive results.
• A research team in the US is trying to learn about this by analyzing a large number of health records.
• Individuals with HIV have a higher risk of lung information and pneumonia from the annual flu, so it may be similar for Covid-19.
• Preliminary data is expected by early fall.

CNN: Covid-19 is Dr. Anthony Fauci’s ‘worst nightmare’ (June 10, 2020)

• “We don’t know the extent of full recovery or partial recovery, so there’s a lot we need to learn,” Dr. Fauci said. We don’t know how those who recovered from Covid-19 will be a few months from now.

STAT: The novel coronavirus attacks the lungs. A biotech company sees a common enzyme as key to protecting them (June 10, 2020)

• The ACE2 enzyme serves normally as part of the “renin angiotensin system” by reducing the amount of angiotensin II (a peptide that narrows blood vessels) just outside of the cell. It reduces the level of angiotensin by converting it to angiotensin-(1-7), which dilates blood vessels. However, angiotensin-(1-7) is also known to reduce inflammation and blood-clotting.
• As the ACE2 enzyme serves as a receptor for SARS-CoV-2, the infection keeps many of these receptor sites from performing their normal role, thus reducing the amount of angiotensin-(1-7) along with its anti-inflammatory and anti-clotting benefit.
• Constant Therapeutics, a small biotech company in Boston, is planning on conducting trials on its intravenous TXA127 drug to test its effectiveness on Covid-19 patients. This drug delivers “a pharmaceutical version of” angiotensin-(1-7), which may compensate for the reduced amounts of this peptide caused by a Covid-19 infection and thereby reduce both inflammation and blood-clotting.

STAT: A national registry could help defeat sepsis, a big contributor to Covid-19 deaths
(June 9, 2020)

• The cytokine storm seen in many Covid-19 patients can lead to life-threatening sepsis. Survival of sepsis leads to temporary or permanent mental and physical impairment in almost 60% of cases and for the elderly an increased risk of death from certain causes within three years.
• “The first step is to gather and analyze reliable and consistent data on who gets sepsis, what treatments work, and how best to support survivors and their families.”
• “A national sepsis registry would build on the existing systems that already capture the information we need: electronic medical record systems, state reporting programs, and forms that are already in use by clinicians.”

Economist: How SARS-CoV-2 causes disease and death in covid-19 (June 6, 2020)
(Requires free registration.)

SciAm: So How Deadly Is COVID-19? (June 5, 2020)

• The author, an emergency physician, explains very clearly how the true mortality rate depends on many factors that do not depend directly on the virus and is difficult to calculate, but he says “we know enough to know that this virus is deadly serious”.
• “Every day for weeks, my colleagues and I have faced wave after wave of COVID patients in their 30s, 50s or 80s, many of them extraordinarily ill. Some of these people have died. Its virulence is astonishing, at least among hospitalized patients. Experienced physicians know that this is nothing like the flu.”
• Covid-19 spreads at least twice as fast as the flu.
• The seriousness of the disease likely depends on the number of viral particles an individual is exposed to, meaning that masks and social distancing are important.
• “Wherever the mortality rates may settle, we have enough information to act responsibly, with carefully phased reopenings and robust testing and contact tracing.”

PopSci: Coronavirus and the Flu: A Looming Double Threat (June 4, 2020)

• A “worst-case scenario” would be Covid-19 and the flu spreading during the upcoming flu season, making it more difficult to diagnose patients and burdening the hospitals. (The 2017–2018 flu stretched the health-care system.)
• However, “flattening the curve” might also reduce the number of flu cases. Human behavior and policy play a big role.
• A study in northern California found that about 20% of those diagnosed with Covid-19 were also infected with a another respiratory virus.
• Science does not know why, but viruses spreading in the same area don’t generally peak at the same.
• Flu activity dropped dramatically in Hong Kong after measures were taken to contain Covid-19 and in the US after the Covid-19 pandemic was declared.
• North Carolina’s state health director says, “We do have a vaccine for flu. Get the vaccine.”

NYT: Who Is Most Likely to Die From the Coronavirus? (June 4, 2020)

• As of June 3, around 90% of deaths in New York and Chicago were of those with chronic underlying health conditions. According to the CDC, such underlying conditions are much more common among poorer people. “Rates of chronic obstructive pulmonary disease, kidney disease and diabetes, for example, among the poorest 10 percent of New Yorkers are estimated to be more that 40 percent higher than the median rate.”
• There’s a “socioeconomic gradient in health”. Richer people have:
  • better diets, housing and working conditions;
  • less exposure to unhealthy environments at home and at work;
  • less stress and healthier physical activity (as in green areas); and
  • better health care.
• “There are many policies that would make a difference: investments in early childhood education, school-based health centers, after-school programs, cognitive-behavioral therapy for adolescents, home-based nursing care, peer-group sessions for pregnant women, better and more affordable housing as well as transportation infrastructure, among others.”

STAT: MIT engineers develop a system to help physicians get the most out of ventilators
(VIDEO) (June 4, 2020)

• Valves on tubes allow for more flexibility in matching patients who need to share a ventilator.

Science: Why coronavirus hits men harder: sex hormones offer clues (June 3, 2020)

• A new hypothesis is that androgen increases the risk of severe Covid-19 by increasing the number of TMPRSS2 enzymes on the cell membrane when it binds to androgen receptors. TMPRSS2 is responsible for cleaving the SARS-CoV-2 spike after it binds to the ACE2 receptor, allowing spherical envelope to fuse onto the cell membrane. An increased availability of TMPRSS2 enzymes would then accelerate the infection of cells.
• There is evidence from prostate cancer research that when androgen binds to the androgen receptor in the prostate, it increases the number of TMPRSS2 enzymes in the cells there.
• Data of Covid-19 patients in Veneto, Italy, show that prostate cancer patients not on androgen deprivation therapy were four times as likely to be infected with Covid-19 than those on the therapy (although data on hospitalization and death were not as significant).
• Two studies in Spain showed there was a significantly higher representation of men with male pattern baldness among Covid-19 patients compared to the general population. This type of baldness is associated with higher levels of a molecule produced when an androgen hormone is metabolized (processed chemically in the body).

NYT: Genes May Leave Some People More Vulnerable to Severe Covid-19 (June 3, 2020)

• Blood type A is linked to a 50% greater likelihood of ending up on a ventilator.
• A “locus” on Chromosome 3 exhibits an even stronger link to Covid-19 severity, but it is not sure which one(s) of six candidate genes:
  • One gene encodes a protein that interacts with the ACE2 receptor.
  • Another gene encodes a signaling protein of the immune system.

Science: Blood vessel attack could trigger coronavirus’ fatal ‘second phase’ (June 2, 2020)

• A new hypothesis by Swiss researchers is that a 3-phase “vicious cycle” causes most of the Covid-19 deaths:
• 1) Endothelial cells normally “help regulate blood pressure, prevent inflammation, and inhibit clotting” (in part by producing nitric oxide (NO)). When damaged by SARS-CoV-2 infection, they send out signal proteins to attract “immune cells and clotting factors“, which try to repair the damage, and to warn nearby endothelial cells. Some cells might self-destruct, spilling out their contents.
• 2) Blood fluid leaks from the capillaries into the alveoli (a symptom of ARDS), white blood cells collect and NO levels likely drop dramatically. Endothelial cells and immune cells produce interleukins and other signaling molecules, which raise blood pressure locally and weaken cell junctions. The exposed membrane below the endothelial cells “triggers uncontrolled clotting”. D-dimer, a known marker is produced when clots degrade.
• 3) The inflammatory response spreads out of control, further driving ARDS and leading to shock.
• The endothelial cells are already “compromised” in the case of diabetes, obesity or cardiovascular issues, which would explain why such conditions lead to higher mortality rates. Therapeutic drugs that treat such conditions might be helpful.” Young people without known risk factors for COVID-19 … might have undiagnosed clotting or autoimmune disorders, such as rheumatoid arthritis, that amplify the effects of SARS-CoV-2 infection”. Anti-clotting, anti-inflammatory, and anti-platelet drugs and statins might help treat patients.

UNC: Researchers map SARS-CoV-2 infection in cells of nasal cavity, bronchia, lungs
(June 2, 2020)

• Researchers found “a striking pattern of continuous variation, or gradient, from a relatively high infectivity of SARS-CoV-2 in cells lining the nasal passages, to less infectivity in cells lining the throat and bronchia, to relatively low infectivity in lung cells”.
  • The infectivity corresponded to densities on the cell membrane of ACE2, TMPRSS2, and furin enzymes.
• “Intriguingly, the virus did not infect airway-lining cells called club cells, despite the fact that these cells express both ACE2 and TMPRSS2.”
• Infection in the lungs appears in patches, providing evidence that the virus is aspirated into the lungs.
• The research team created a tool by engineering SARS-CoV-2 to produce light by phosphorescence, which can be useful in other studies.

NYT: After 6 Months, Important Mysteries About Coronavirus Endure (June 1, 2020)

• Important mysteries that remain:
  • “How many people have been infected.”
  • “The amount of virus it takes to make you sick.”
  • “Why some people get so much sicker than others.”
  • “The role of children in spreading the virus.”
  • “When or where the new coronavirus started spreading.”
  • “How long you’ll be immune after infection.”

CNN: One in 10 Covid-19 patients with diabetes die within a week, study finds (May 30, 2020)

• In one study by French researchers at day 7 of hospitalization about 20% of diabetic Covid-19 patients were already on ventilators and another 10% had already died.
• “So, basically being above the age of 70 and being male with diabetes and being overweight or obese really had a major [effect] on the outcome.”

nature: Coronavirus research updates: The nose could be the body’s entry point to infection (May 29, 2020)

• “The authors speculate that [think that maybe] the virus gets a foothold in the nose, then sneaks down the respiratory tract when breathed into the airways. They say the results support the use of masks and preventative measures such as nasal cleansing.”

This is the first time I see findings that suggest the effectiveness of “nasal cleansing” as a “preventative measure”. I’m wondering if this might soon be advised by experts. – MH

NYT: It’s Not Whether You Were Exposed to the Virus. It’s How Much. (May 29, 2020)

STAT: ‘It’s something I have never seen’: How the Covid-19 virus hijacks cells
(May 21, 2020)

• Interferon is a signaling molecule that tells neighboring cells to activate genes that slow down a viral attack. Chemokines are signaling molecules that summon B cells (that make antibodies) and “killer” T cells. Normally, interferon slows down the replication of the virus for a few days until the chemokines call for the cells that ultimately produce antibodies and finish the counterattack.
• SARS-CoV-2, in a way never seen before, blocks the set of genes in the host cell that produce interferon, but activates the set of genes that produce chemokines. In this way, viral replication is not slowed down, but the immune cells are called to action. This kills cells in the lungs that are a part of oxygen exchange, causing severe respiratory distress. [As chemokines are a subset of cytokines, this can explain the cytokine storm that has so far mystified scientists. – MH]
• It is the ORF3b gene in the viral RNA that produces a protein that blocks the genes that produce interferon.
• The elderly and individuals with comorbidities already have a weaker response to interferon, thus giving an explanation for their more severe cases.
• A new idea is therefore to treat patients with “type 1” interferon. One study showed that interferon can slow down the replication of SARS-CoV-2 (by a factor of up to 10,000) in lab-grown cells. However, there are some serious side effects to consider when treating with interferon. Clinical trials are already underway.

Science: Doctors race to understand rare inflammatory condition associated with coronavirus in young people (May 21, 2020)

• A small number of children with Covid-19 have what the CDC now calls multisystem inflammatory syndrome, which is either the rare Kawasaki disease (known to affect only between one and three children in 10,000) or something similar to it. Among other symptoms, it includes inflammation in medium-size blood vessels throughout the body. It can lead to heart problems, loss of blood pressure or shock.
• This is accompanied by a cytokine storm that is more similar to that seen in many adults with severe symptoms of Covid-19 than to a typical case of Kawasaki disease.
• It is believed that there is a “genetic component” for risk to this condition. Research is being done through genetic testing that may lead to future treatments for children found to be at higher risk.
• One “puzzle” is that this condition has not been found in Covid-19 patients in Asia. This may be because it is so rare or because of a mutation in a strain coming from Europe.
• Two research projects are discussed that analyze data of children world-wide that have had this condition.
• It is also uncertain if adults might also be getting this condition.

nature: Structure of replicating SARS-CoV-2 polymerase (May 21, 2020)

One animation is such a beautiful rendering of the structure of the enzyme that makes copies of SARS-CoV-2 RNA in a host cell. Another visualization shows how this polymerase enzyme makes a copy of an RNA strand. (The blue helical strand is the original RNA and the red strand is the new RNA strand being created.)

STAT: Ventilators can save people with serious Covid-19. The people behind them are even more important (May 19, 2020)

• A recent study indicates that 76% of NYC patients between the ages of 18 and 65 who were placed on ventilator died.
• The author, a medical care worker at a pediatric ICU (PICU) in NYC, gives reasons for why no ventilated patients had died in her unit although severely sick: much younger patients (maximum age in their 40s); patients had survived the transfer, meaning they were more stable; but also a higher staffing ratio (one or two patients per nurse vs. four); proper training vs. new or retrained personnel without the proper training.
• The focus during the height of the crisis in NYC was “ventilators”, but much more needs to be done for the patients on them.

SciAm: From Headaches to ‘COVID Toes,’ Coronavirus Symptoms Are a Bizarre Mix
(May 18, 2020)

• There seems to be two possible main causes for the wide range of complications:
  • Inflammation, a response of an immune system that is overreacting.
  • Blood clotting anywhere in the blood vessels.

The Paris Review: How to Draw the Coronavirus (May 1, 2020)

• An animated rendering of the SARS-CoV-2 spike:

NYT: ‘Straight-Up Fire’ in His Veins: Teen Battles New Covid Syndrome (May 17, 2020)

• 14-year-old had heart failure from Multisystem Inflammatory Syndrome in Children caused by Covid-19.
• Once the heart and blood vessels fail, other organs can follow.
• “She told me if I go home now, by tomorrow, I’ll be dead.”

BBC: Coronavirus: A third of hospital patients develop dangerous blood clots
(May 16, 2020)

• Quickly spreading molecules in the blood may be causing blood clots.
• Blood thinners for preventing clots don’t always work, but increasing doses can cause bleeding and death.
• Another way to treat is by reducing the inflammation in the lungs that leads to clots.

nature: The sprint to solve coronavirus protein structures — and disarm them with drugs
(May 15, 2020)

• To stop the pandemic, it might be necessary to quickly find out the virus’s protein structures in order to design drugs and vaccines.
• One day after receiving the SARS-CoV-2 genome online on January 10, a world-wide network of scientists were ready to focus on this work.
• “The rate at which people are working at this is an order of magnitude faster than they’ve been able to work on other problems.”

Although this Nature article is a rather technical, in particular in its use of technical terms, I still recommend reading it, even if you can’t understand all of it. – MH

Science: The coronavirus’ rampage through the body (VIDEO) (May 14, 2020)

CNN: Covid-19 isn’t just a respiratory disease. It hits the whole body (May 13, 2020)

• A 38-year old man had an aortic occlusion (a large blood clot in the main artery exiting the heart) that kept blood from reaching his leg. This is fatal in 20% to 50% of patients and rarely occurs in a 38-year-old.
• Covid-19 can also cause more than one organ to fail.
• It seems the virus causes inflammation that leads blood clots. The virus must be attacking the arteries directly.
• If the virus affects blood vessels, then any organ can be affected. “It is a very confusing picture. It’s going to take time to understand.”
• “It might cause children’s immune systems to overreact.”

DW: How the novel coronavirus attacks our entire body (May 11, 2020)

Washington Post: Doctors keep discovering new ways the coronavirus attacks the body
(May 10, 2020)

• “Damage to the kidneys, heart, brain — even ‘Covid toes’ — prompts reassessment of the disease and how to treat it

NYT: Surviving Covid-19 May Not Feel Like Recovery for Some (May 10, 2020)

• “Debilitating symptoms can last long after a person’s body has gotten rid of the coronavirus, a reality Italians are now confronting.”
• “It’s not the sickness that lasts for 60 days, it is the convalescence,” [an Italian hospital director] said. “It’s a very long convalescence.”
• “Any pneumonia damages the lungs, which can take months to heal, and doctors warn that the harm might not be completely reversible.”
• “Lack of energy and the sensation of broken bones…”

nature: Coronavirus blood-clot mystery intensifies (May 8, 2020)

• “Studies from the Netherlands and France suggest that clots appear in 20% to 30% of critically ill COVID-19 patients.”
• Scientists are beginning to do studies based on the latest hypotheses, but are also trying to test anti-clotting medications.
• “Blood thinners don’t reliably prevent clotting in people with COVID-19, and young people are dying of strokes.”
• “D-dimer“, a piece of a protein produced when a clot dissolves is a “powerful predictor of mortality in hospitalized patients infected with coronavirus”.
• Clots are also found in capillaries (the smallest blood vessels in the body).
• “’This is really very new.’ It might explain “critically low blood-oxygen readings, and why mechanical ventilation often doesn’t help”.
• It might be that endothelial cells in the lining of blood vessels, which we have very recently discovered are targeted by Covid-19, lose their ability to keep the blood from clotting. Another possibility is that the overreaction of the immune system, known to occur in many patients, is indirectly causing the clotting.
• Patients might have “risk factors for clotting”, “a genetic predisposition to clotting”, or be “taking medications that increase the risk”.
• A “[r]ace to new therapies” based on these findings is also discussed.

NatGeo: They don’t struggle to breathe—but COVID-19 is starving them of oxygen
(May 8, 2020)

• One alarming symptom robs many patients of blood oxygen well before they notice. Doctors are racing to understand it.
• Silent hypoxia: “Unlike many other respiratory diseases, COVID-19 can slowly starve the body of oxygen without initially causing much shortness of breath.” Individuals dangerously low on oxygen are surprisingly “awake, calm, and responsive”.
• “There have not yet been thorough studies of whether early detection of silent hypoxia can improve COVID-19 outcomes,” but “prolonged hypoxia may strain the heart and perhaps other bodily systems”.

1. The overactivation of the “immune response” could trigger cell damage that “could hinder the passage of oxygen from alveoli to the blood, while carbon dioxide … is less impacted”.
2. Another possibility may be that the disease creates a mismatch between oxygen’s movement in the lungs and the flow of blood”. More blood might be “flowing to damaged lung areas, while less is passing through healthy parts”.
3. “Blood flow to oxygen-rich zones of the lung might alternatively be hindered by tiny clots in the blood vessels. … Some doctors are debating the use of blood thinners.”

• COVID-19 patients are being recruited “for a study using an array of biosensors, including pulse oximetry, for remotely tracking patients’ conditions” to potentially catch patients early in the disease’s progression”.

Univ. of Cincinnati: By the third day most with COVID-19 lose sense of smell
(May 8, 2020)

• “At least 61% of the patients [in a study] reported reduced or lost sense of smell.”
• “We also found in this study that the severity of the loss of smell is correlated with how bad your other COVID-19 symptoms will be.”
• A “decreased sense of smell may be an indicator” of which patients should then be treated early with an antiviral drug such as remdesivir.

NYT: In the Fight to Treat Coronavirus, Your Lungs Are a Battlefield (May 8, 2020)

STAT: Photos: One day inside a Boston hospital’s response to Covid-19 (May 7, 2020)

The puzzling questions of the coronavirus: A doctor addresses 6 questions that are stumping physicians (May 6, 2020)

1. Some evidence suggests that patients experience low oxygen saturation days before they appear in the ER. If so, is there a way to treat patients earlier?
2. Young adults are having strokes with COVID-19. Does this suggest the illness is more of a vascular disease than a lung disease in that age group?
3. The Centers for Disease Control and Prevention recently updated its official list of symptoms. Does this suggest anything unusual about COVID-19?
4. How can so many people experience such mild symptoms and others quickly die from it?
5. The disease appears now to affect various other organs—heart and kidney, for example. What does this suggest?
6. Why are some countries not experiencing as much COVID-19 as the U.S., Europe and China?

NYT: ‘An Anvil Sitting on My Chest’: What It’s Like to Have Covid-19 (May 6, 2020)

STAT: Giving blood thinners to severely ill Covid-19 patients is gaining ground
(May 6, 2020)

• “Treating Covid-19 patients with medicines to prevent blood clots might help reduce deaths in patients on ventilators, based on new observational data.”
• “A team from Mount Sinai Health System in New York on Wednesday reported better results for hospitalized Covid-19 patients who received anticoagulant drugs compared to patients who didn’t.”

NPR: How The Novel Coronavirus Hijacks Our Defenses (VIDEO) (May 5, 2020)

nature: Profile of a killer: the complex biology powering the coronavirus pandemic
(May 4, 2020)

• “Coronaviruses are also one of the few RNA viruses with a genomic proofreading mechanism — which keeps the virus from accumulating mutations that could weaken it. That ability might be why common antivirals [have failed to] weaken viruses by inducing mutations.”
• “[C]oronaviruses have a special trick that gives them a deadly dynamism: they frequently recombine, swapping chunks of their RNA with other coronaviruses.”
• “[T]he virus can … bypass the throat cells and go straight down into the lungs. Then patients might get pneumonia without the usual mild symptoms such as a cough or low-grade fever that would otherwise come first.”
• “SARS-CoV-2 can shed viral particles from the throat into saliva even before symptoms start, and these can then pass easily from person to person. SARS-CoV was much less effective at making that jump, passing only when symptoms were full-blown, making it easier to contain.”
• “The virus might be able to infect various organs or tissues wherever the blood supply reaches.”
• “[A]lthough genetic material from the virus is showing up in … various tissues, it is not yet clear whether the damage there is being done by the virus or by a cytokine storm.“

NYT: The Covid-19 Riddle: Why Does the Virus Wallop Some Places and Spare Others?
(May 4, 2020)

• Factors suggested “that could help explain where the virus thrives and where it doesn’t: demographics, culture, environment and the speed of government responses”.
• It may be due to a combination of these factors: Age; cultural distance (between individuals); heat and light; “early and strict lockdowns”; plain luck.

CR: What It’s Like to Recover From COVID-19 (May 2, 2020)

• It could take weeks or months to bounce back from the sometimes serious damage to the lungs and heart

c&en: How structural biologists revealed the new coronavirus’s structure so quickly
(May 2, 2020)

NYT: What Is ‘Covid Toe’? Maybe a Strange Sign of Coronavirus Infection (May 1, 2020)

• “At first, the toes look swollen and take on a reddish tint; sometimes a part of the toe is swollen, and individual lesions or bumps can be seen. Over time, the lesions become purple in color.”
• “One hypothesis is that they are caused by inflammation, a prominent feature of Covid-19.”
• “Other hypotheses are that the lesions are caused by inflammation in the walls of blood vessels, or by small micro clots in the blood.”

NPR: Coronavirus FAQS: What’s A Pulse Oximeter? Is It A Good Idea To Buy One?
(May 1, 2020)

CNN: Critics said the flu kills more than coronavirus. Why that’s not a fair comparison — and now, it’s not even true (May 1, 2020)

NYT: The Coronavirus: What Scientists Have Learned So Far (April 30, 2020)

• “Men are more likely to die from an infection compared to women, possibly because they produce weaker immune responses and have higher rates of tobacco consumption, Type 2 diabetes and high blood pressure than women, which may increase the risk of complications following an infection.”

Medical News Today: Loss of smell may suggest milder COVID-19, study finds
(April 30, 2020)

NYT: COVID-19 Complication Seen in Children Is ‘Rare’, WHO Says (April 29, 2020)

• “Three U.S. children infected with the virus are being treated for a rare inflammatory syndrome that appears similar to one that has raised concerns in Britain, Italy and Spain.”
• “There are some recent rare descriptions of children in some European countries that have had this inflammatory syndrome, which is similar to Kawasaki syndrome, but it seems to be very rare.”

The Atlantic: Why the Coronavirus Is So Confusing (April 29, 2020)

• A very informative article!
• “This is how science actually works. It’s less the parade of decisive blockbuster discoveries that the press often portrays, and more a slow, erratic stumble toward ever less uncertainty.” (Science is generally a slow advancement towards becoming more and more certain of “facts”.)

SciAm: ‘Spider-Man’ Immune Response May Promote Severe COVID-19 (April 28, 2020)

Science: Why don’t some coronavirus patients sense their alarmingly low oxygen levels?
(April 28, 2020)

NPR: CDC Adds 6 Symptoms To Its COVID-19 List (April 27, 2020)

• The CDC has added “six more conditions that may come with the disease: [1] chills, [2] repeated shaking with chills, [3] muscle pain, [4] headache, [5] sore throat and [6] new loss of taste or smell.”

Medscape: COVID-19 Linked to Large Vessel Stroke in Young Adults (April 24, 2020)

• “It’s been surprising to learn that the virus appears to cause disease through a process of blood clotting,” Dr. Oxley of Mount Sinai Health System in New York City told Medscape Medical News.

MedicalXPress: Higher levels of NETs in blood associated with more severe COVID-19
(April 24, 2020)

• “New research finds a connection between destructive white blood cells and a more severe disease course in patients with COVID-19,” showing evidence of an overactive immune system.

WebMD.com: The Great Invader: How COVID Attacks Every Organ (April 23, 2020)

• “We have underestimated and misunderstood COVID-19 since it first appeared.”
• “It’s joined the ranks of other ‘great imitators’ — diseases that can look like almost any condition.”
• It interferes with signals for immune responses, to give it time to spread before causing symptoms!
• If the immune system doesn’t stop the virus soon enough, it ends up in the lungs or in the digestive system.
• From there it can go to attack “other organs that have ACE2 receptors … including heart muscle, kidneys, blood vessels, the liver, and potentially the central nervous system.”
• It has not yet been confirmed scientifically if the virus can attack nerve cells and travel this way, for example, from the nasal passages to the brain. If so, this can explain how the sense of smell is affected. (Viral particles have been found in the fluid around the brain it at least one patient.)
• “In one study from the Netherlands, 31% of patients hospitalized with COVID-19 got [blood] clots while on blood thinners.”
• “Targeting or blocking [the ACE2] receptor as a treatment strategy to prevent viral entry into cells may actually worsen blood pressure, increase the risk of heart failure and kidney injury, and increase inflammation that may worsen lung injury.”
• “Timing is likely to be key in treatment strategies. For example, patients may need a drug to boost the immune system early on in the disease, and then one to tamp it down if the disease progresses and cytokine markers begin to rise.”
• Skin conditions related to Covid-19 are described.

MIT: Researchers identify cells likely targeted by Covid-19 virus (April 22, 2020)

• Researchers at MIT, Harvard and other institutes have found specific types of cells that the virus targets in the lung, the nasal passages, and the intestine.
• These cells have two proteins, ACE2 on the cell membrane that binds to a spike on the virus and TMPRSS2 that “activates” the spike to allow the RNA genetic material to enter the cell.
• They used data that came from the Human Cell Atlas project and other sources to discover which human cells express these proteins (i.e, assemble them according to genes in their DNA) .
• The cells in the nasal passages are “goblet secretory cells“, which produce mucus. The cells in the lungs are type II pneumocytes in the alveoli (tiny air sacs at the end of the air passages), which have already been known to be affected by the virus.
• Surprisingly, “expression of the ACE2 gene appeared to be correlated with activation of genes that are known to be turned on by interferon, a protein that the body produces in response to viral infection”. Experiments confirmed that interferon did exactly that. However, interferon is part of the immune system, meaning that the virus is “hijacking” part of the immune system to enter cells.
• Interferon is sometimes used to treat other viral infections. This finding then complicates matters for using it to fight Covid-19.
• Click here for a pre-print of the research report.

genengnews.com: Connecting SARS-CoV-2 Dots: Pinpointing Targeted Cells and Exploring Interferon’s Intriguing Role (April 22, 2020)

• An article on the same research described in MIT’s article above.
• “It’s also too soon to try to relate the study findings to the ‘cytokine storm,’ a runaway inflammatory response that has been reported in very sick COVID-19 patients. Cytokines are a family of chemicals that rally the body’s immune responses to fight infections, and interferon is part of the family.”
• “It might be that we’re seeing a cytokine storm because of a failure of interferon to restrict the virus to begin with, so the lungs start calling for more help. That’s exactly what we’re trying to understand right now.”

NYT: Alarmed as COVID Patients’ Blood Thickened, New York Doctors Try New Treatments
(April 22, 2020)

• “As colleagues from various specialties pooled their observations, they developed a new treatment protocol. Patients now receive high doses of a blood-thinning drug even before any evidence of clotting appears.”
• “The American Society of Hematology, which has also noted the clotting, says in its guidance to physicians that the benefits of the blood-thinning therapy for COVID-19 patients not already showing signs of clotting are ‘currently unknown’.”

CNN: Doctors try to untangle why they’re seeing ‘unprecedented’ blood clotting among Covid-19 patients (April 22, 2020)

STAT: He ran marathons and was fit. So why did Covid-19 almost kill him? (April 21, 2020)

• The patient was a doctor. Extremely high levels of two proteins in the body, ferritin and C-reactive protein, indicated inflammation and a possible cytokine storm, an overactive reaction of the immune system that is thought to be the cause of death for many young Covid-19 patients with no prior health condition. He tried several unproven drugs. Two hours after an infusion of the drug tocilizumab (sold as Actemra), his fever subsided and his oxygen levels were near normal. “It appeared the drug had worked.” (Tocilizumab, a promising drug for Covid-19 patients, is an anti-inflammatory drug that was approved in 2017 to treat cytokine storms and has also appeared to work on other Covid-19 patients.)

STAT: New analysis recommends less reliance on ventilators to treat coronavirus patients
(April 21, 2020)

The Atlantic: Why Some People Get Sicker Than Others (April 21, 2020)

The Lancet: Endothelial cell infection and endotheliitis in COVID-19 (April 20, 2020)

• A Swiss study analyzing tissue samples of three Covid-19 patients from postmortems of the two who died and from an intestinal resection of the male patient that survived.
• Viral inclusion structures (spots visible at locations where a virus enters a cell) are found in endothelial cells of blood vessels (cells of one layer of the inside wall of blood vessels).
• Endotheliitis (inflammation of these endothelial cells) was discovered in the small intestine of the patient that survived (patient 3) and in patient 2; in the lung, heart, kidney and liver of patient 2; and evidence thereof in the heart, small bowel and lung of patient 1.
• A resulting endothelial dysfunction can lead to organ ischemia (inadequate blood supply that can cause necrosis, death of at least part of the organ, observed in this study), inflammation with edema (collection of fluid), and a pro-coagulant state (capable of clotting blood).

NYT: The Infection That’s Silently Killing Coronavirus Patients (April 20, 2020)

• An article by an ER doctor at Bellevue Hospital in New York City that explains how hypoxia (insufficient oxygen reaching tissues) is developing in Covid-19 patients, but well before the patient experiences any shortness of breath and often without him/her aware of any symptoms of pneumonia.
• Dr. Levitan recommends the use of a pulse oximeter (a device, obtainable at pharmacies, which is placed on a finger and measures oxygen in the blood and the pulse rate) to warn individuals when oxygen levels are low enough that hospitalization is required.

NYT: An Overlooked, Possibly Fatal Coronavirus Crisis: A Dire Need for Kidney Dialysis
(April 18, 2020)

• “Ventilators aren’t the only machines in intensive care units that are in short supply. Doctors have been confronting an unexpected rise in patients with failing kidneys.”

Science: How does coronavirus kill? Clinicians trace a ferocious rampage through the body, from brain to toes (April 17, 2020)

• A very well written article providing excellent insight into the current theories of how the virus spreads throughout the body, damages organs and kills.

WebMD.com: Cytokine Storms May Be Fueling Some COVID Deaths (April 17, 2020)

Harvard: Coronavirus and the heart (April 14, 2020)

• An overview of the ways currently thought that Covid-19 may damage the heart, even in patients with no prior history of heart disease. This includes the effect of a “cytokine storm” that may also damage other organs.

BBC: UK Biobank: DNA to unlock coronavirus secrets (April 14, 2020)

• “A vast store of DNA [from volunteers] is being used to study why the severity of symptoms for coronavirus varies so much.”

STAT: How much of the coronavirus does it take to make you sick? The science, explained
(April 14, 2020)

WebMD: COVID May Trigger ‘Cytokine Storm’ in Some Cases (April 9, 2020)

• Here is a simply written explanation of how medical science so far believes that a cause of death from Covid-19 may be from the body’s own immune system being made to work on overdrive at a “lethal level”. A cytokine is any of various kinds of signaling molecules that call for an immune response. A “cytokine storm” is therefore the condition in which they appear in dangerously high numbers in the body.

LiveScience: The mysterious connection between the coronavirus and the heart
(April 8, 2020)

• Not only the lungs, but also organs like the heart can be damaged by the virus.

NPR: Why Some COVID-19 Patients Crash: The Body’s Immune System Might Be To Blame
(April 7, 2020)

• Covid-19 may cause the immune system to attack the patient’s own body by what is known as a “cytokine storm“.

Doctors Puzzle Over COVID-19 Lung Problems (April 7, 2020)

• More than a half of the Covid-19 patients in Northern Italy have an unusual problem with their lungs. Go to Clinical news to learn more about this problem.

SciAm: Heart Damage in COVID Patients Puzzles Doctors (April 6, 2020)

• The heart is also damaged in some Covid-19 patients.

How Coronavirus Attacks the Body (VIDEO) (April 6, 2020)

Vox: Coronavirus is not the flu. It’s worse. (April 1, 2020)

• The following is a video explaining several reasons for why Covid-19 is not the flu. In fact, it is quite dangerous in many ways:

BBC: Coronavirus: What it does to the body (March 14, 2020)