Welcome back to Axios' special report about the science of pandemics. This week we look at zoonotic diseases, antibody treatments, how researchers are trying to keep up with a changing understanding of COVID-19, and more.
This week's newsletter is 1,830 words, about a 7-minute read.
Illustration: Sarah Grillo/Axios
The novel coronavirus is the latest in a long list of pathogens that have jumped from animals to human beings, triggering pandemics that have killed hundreds of millions, Axios' Bryan Walsh writes.
Why it matters: COVID-19 underscores the desperate need to better understand and control the intersection of animal and human health. Preventing future pandemics will come down in part to better policing the border zones between animal health and human health.
The big picture: Nearly 1.7 million as yet undiscovered viruses are believed to exist in wildlife. Thomas Gillespie, a disease ecologist at Emory University, notes that we still lack data for almost 90% of zoonotic viruses in wild mammal species.
"If we could get hold of emerging viruses before they fully adapt to humans, it would help us better understand it and develop better treatments. That might help us avoid the next viral crossover."— Peter Ben Embarek, WHO zoonoses expert
What's happening: Many experts are urging wet markets, where live animals and humans may be in close contact, be closed.
How it works: The most widely accepted theory of the origins of COVID-19 is a textbook example of how "zoonotic spillovers" occur.
The bottom line: Humans and animals share this planet, and increasingly they share deadly pathogens as well. If we don't fully recognize that shared threat, COVID-19 won't be the last zoonotic pandemic.
Illustration: Aïda Amer/Axios
Researchers are racing to develop treatments based on antibodies to block or neutralize the coronavirus in patients, with the hopes these could be ready for possible emergency use by the fall, Axios' Eileen Drage O'Reilly writes.
Why it matters: Many experts feel antibodies from recovered patients and synthesized antibody drugs could be important bridge treatments for COVID-19 during the months or years until a successful vaccine is available.
Details: Antibody therapies can be synthesized or derived from human plasma or animals that have been infected.
Plasma from recovered COVID-19 patients has "investigational" status from the Food and Drug Administration and is being used in various clinical trials, in acute care facilities, and in individuals with serious infections who receive the plasma from their physicians.
Monoclonal antibody drugs are also being developed to target specific proteins or functions of the SARS-CoV-2 virus to neutralize and/or block it. There are at least 50 candidates in development, including by Regeneron and Eli Lilly.
One of the problems with this coronavirus is that scientists don't yet know which part of SARS-CoV-2 is best to target.
Illustration: Eniola Odetunde/Axios
Solutions for COVID-19 are being developed at the same time as knowledge about the disease evolves, a serious challenge for doctors treating patients and for researchers trying to create vaccines and treatments.
Why it matters: What was first thought of as a respiratory infection now appears much more complex, making efforts to tackle the disease more complicated.
What's happening: When the world first encountered COVID-19 four months ago, it was deemed a respiratory infection that hammers the lungs. That's still the case, but in recent weeks, clinicians have been reporting wide-ranging manifestations of the disease in some people.
Details: Renal failure, sepsis, damaged blood vessels, skin lesions, stroke, gastrointestinal problems, and blood clots in the lungs and kidneys are being seen in some COVID-19 patients.
"It comes across more as a systemic disease exhibited initially as a respiratory disease," says Poznansky. It's unclear whether the cause is the virus itself, the immune system's response to it or a side effect of treatment.
That has implications for developing vaccines.
What to watch: The evolving understanding of the disease will feature in regulatory discussions.
The bottom line: Pandemics bring a potent mix of uncertainty and urgency to science that experts say requires both nimbleness and rigor to navigate.
Why does COVID-19 wallop some places and spare others? (Hannah Beech et al. — NYT)
The problem with stories about dangerous coronavirus mutations (Ed Yong — The Atlantic)
COVID-19 is not all good for wildlife (Brian Owens — Hakai)
Coping with the pandemic's hidden mental health toll (Kim Hart — Axios)
Illustration: Aïda Amer/Axios
The question of whether to deliberately infect volunteers with SARS-CoV-2 in order to test vaccines for COVID-19 is being hotly debated by scientists, ethicists and lawmakers.
The big picture: Controlled human infection studies have been used for centuries to evaluate vaccine doses and candidates for influenza, norovirus and other diseases. But COVID-19, with its severity, novelty and unknowns, presents thorny questions for this scientific tool.
How it works: Vaccine studies typically involve immunizing people with a vaccine (and others with a placebo), waiting for them to be exposed to the virus and seeing if the vaccine protects them.
What's happening: No COVID-19 challenge trial is planned yet, but more than 14,000 people have said they'd participate in one, and scientists, ethicists, lawmakers and others are weighing in on how they might be done.
"They're controversial, and right now there is so much we don't know," says ethicist Seema Shah of Lurie Children's Hospital of Chicago, an author of a new paper in the journal Science that outlines an ethical framework for using the studies for COVID-19. "But it is worth the investment in laying the groundwork to do such a study."
Proponents say the studies could speed up data collection about the effectiveness of a vaccine — especially if social distancing or a waning outbreak limit peoples' exposure to the virus — and therefore its availability.
Yes, but: There is currently no treatment to stop COVID-19 from progressing to a severe disease, making a challenge trial risky right now, says Myron Levine, associate dean for global health, vaccinology and infectious diseases at the University of Maryland School of Medicine.
"Personally, in the absence of a way to turn this off, I don’t think we should go ahead because I don’t think the risk and what we learn bring us faster to where we want to be."— Myron Levine
The bottom line: Challenge trials can play a role in understanding disease, but there are open questions about when and how they should be used for COVID-19.
Editor's note: The last story has been updated to clarify that Myron Levine is with the University of Maryland School of Medicine.
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