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Genetic Linkage

The First COVID-19 Vaccines: What’s mRNA Got To Do With It?

Most of us have an intuitive understanding of how a vaccine works: show the immune system a bit of a pathogen, or something mimicking it, and trick it into responding as if natural infection is happening. The COVID-19 pandemic ushered in a flood of vaccine options.

 

When I was writing "How the various COVID vaccines work," which ran here at DNA Science on September 10, I had to keep reviewing summary charts to remember who was doing what. Vaccine technology has gone beyond live, weakened, or killed virus, even past the once-groundbreaking subunit vaccines that present parts of a pathogen, like the hepatitis B surface antigen or pertussis toxin. Now we have DNA and RNA vaccines too, delivered in different ways.

 

The first two vaccines against COVID-19, Tozinameran (the Pfizer/BioNTech vaccine) and mRNA-1273, Moderna's still unchristened candidate on the brink of emergency use authorization, are mRNA. And that's confusing people, based, perhaps, on when they took high school biology (more on that coming). So here's a brief consideration of mRNA and how it can alert the immune system to fight SARS-CoV-2.

 

To continue reading, go to my blog DNA Science at Public Library of Science.

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Are Old Vaccines Helpful Against COVID-19?

The idea that old vaccines might have a role in the fight against COVID-19 has been floated since the early days of the pandemic. Vaccines stimulate the broad, innate immune response, which appears to play a key role in fighting COVID-19. Can the approach bridge the time until entire populations are vaccinated specifically against SARS-CoV-2?

 

Three vaccines dominate the discussion: bacillus Calmette-Guérin (BCG) against tuberculosis; measles, mumps, and rubella (MMR); and oral polio vaccine (OPV).

 

To continue reading, go to MedPage Today, where this article first appeared.

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Why Do Males Fare Worse With COVID-19? A Clue From Calico Cats

Early on in the pandemic, a worse clinical scenario for the male of the species emerged. A study published mid-May from Italian researchers offered early statistics from the WHO and Chinese scientists: a death rate of 1.7% for women and 2.8% for men. Then Hong Kong hospitals reported that 15% of females and 32% of males with COVID-19 needed intensive care or had died.

 

In July a Perspective published in Nature Reviews Immunology from researchers at Johns Hopkins University and the University of Montreal noted a similar "male bias" for other viral infections, including SARS and MERS. By then, the wide community testing in South Korea and data from the U.S. indicated 1.5-fold higher mortality for men for COVID-19. The pattern repeated in 38 countries, for patients of all ages.

 

Now a new study published in Nature Communications expands the increased risk for those who have only one X chromosome

 

To continue reading, go to my DNA Science blog at Public Library of Science.

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Worse Than COVID? The Tasmanian Devil’s Contagious Cancer

It's hard to imagine anything worse than the horrors at our hospitals right now. But in a recent JAMA webinar, Nicholas Christakis, Yale Sterling Professor, put the fatality rate of COVID-19 into historical perspective:

 

"Bad as it is, the fatality rate, at .5-.8%, isn't as bad as bubonic plague, which would kill 50% of a population in a few months. Or Ebola at 80%. Or smallpox at 95%. It could have been so much worse." He's a physician, scientist, public health expert, and sociologist.

 

It's an unusual viewpoint to downplay the horror of this moment in time, but Dr. Christakis's new book, "Apollo's Arrow: The Profound and Enduring Impact of Coronavirus on the Way We Live," takes a broader look. He said at the webinar:

 

"This way we're living right now seems alien and unnatural, but plagues aren't new to our species, just new to us. People have struggled with plagues for thousands of years. The Iliad opens with a plague on the Greeks and Apollo reigns down, the Bible, Shakespeare. What's different about our current experience is our time in the crucible happens to be occurring when we can create a vaccine in real time. The fact that we have the technological capability to respond within a year with phase 3 trials of active agents is mind-boggling."

 

We aren't the only species subject to unseen pathogens, including the viruses that aren't even cells or technically alive, just borrowed bits of our own genomes turned against us. With Dr. Christakis's wider view in mind, I noticed a new article about an infectious cancer in Tasmanian devils. It combines two terrors.

A Transmissible Cancer

 

 

To continue reading, go to my blog DNA Science at Public Library of Science, where this post first appeared.

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Dr. Paul Offit Talks COVID Vaccines, With JAMA’S Howard Bauchner

Science and medical writers have been under an avalanche of information for nearly a year now, as we translate technical information about COVID-19 for the public. Links to the latest journal articles overload our inboxes, but, at the beginning and now during another surge, tracking down experts to interview has been difficult. They're simply too busy saving lives.

 

A critical resource for me has been the series of JAMA Live Q+A webinars for the media hosted by Howard Bauchner, editor-in-chief of the Journal of the American Medical Association. It is wonderful to hear the top clinicians and researchers speak freely, at length, and in context, or meander – a nice contrast to the echoing soundbites of mainstream media.

 

JAMA webinar speakers have included the career scientists who've already led us through the waters of HIV/AIDS, hepatitis, influenza, Ebola, zika, SARS, and other epidemics and pandemics. Anthony Fauci is a frequent guest – I wrote up his talk with FDA's Peter Marks here.

 

The webinars also feature the young clinicians battling our new enemy. Early on, Maurizio Cecconi's session, "Coronavirus in Italy: Report From the Front Lines," brought me to tears. The head of the Anaesthesia and Intensive Care Department at Humanitas Research Hospital in Milan, Dr. Cecconi described, at the webinar and in a report (both accessible here), the admission of "patient zero" to the ICU in Lombardy, on February 20, 2020, and how his infection was traced to a local friend who'd had contact with an infected person from China. The 38-year-old was initially not very ill and partied a lot. And the rest is medical history.

 

Recently Dr. Bauchner spoke with Paul Offit, who directs the Vaccine Education Center and is an attending physician in the Division of Infectious Diseases at Children's Hospital of Philadelphia. He's on the FDA Advisory panel that will meet December 10 to discuss Pfizer's COVID-19 vaccine and on the 17th to consider Moderna's.

 

Dr. Offit is best known for co-inventing a vaccine against rotavirus, a diarrheal disease that has claimed millions of lives. It became available in the US in 2006, and is on the World Health Organization's list of essential medicines. The clinical trials for the rotavirus vaccine RotaTeq took four years and involved 70,000 participants – much more typical than the lightning speed of the COVID vaccine trajectory.

 

Here's the Q+A from December 2, lightly edited, with my explanations in parentheses. I've omitted the discussion of who gets vaccine when – that's all over the news.

 

To continue reading, go to my blog DNA Science at Public Library of Science.

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