Lewis: hello welcome your health soon a Scientific American Podcast series!
Fishman: This show focuses on the latest important health news and discoveries that affect your body and mind.
Each episode dives into one topic. Discuss diseases, treatments, and some controversies.
Lewis: It also demystifies medical research in ways you can use to stay healthy.
Lewis: I’m Tanya Lewis
Fishman: I’m Josh Fishman
Lewis. We are the senior health editors of Scientific American. Today is the story of the rsv vaccine. After decades of trying, we may be on the verge of getting some safe vaccines and other treatments for this nasty virus.
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Lewis: If you have small children, [or as my friends with kids like to call them, adorable germ factories] You’ve probably heard of or had RSV.
It stands for respiratory syncytial virus.
Most people are infected by the age of 2-3 years and remain infected for the rest of their lives.
Last fall had a particularly bad RSV season as the COVID-19 pandemic changed some of the seasonal virus patterns.
Fishman: You say COVID has made RSV even more prevalent than usual. how does that happen?
Lewis: COVID precautions essentially slowed down RSV transmission as everyone was social distancing….
…. But then when the kids started going back to school again and they all got sick at the same time, we had a really big wave.
Lewis: Symptoms of RSV often resemble the common cold. However, for very small babies and older adults, it can be very dangerous.
Bernie Graham: RSV causes severe respiratory illness in young children. It is also cumulatively the leading cause of hospitalization in children under the age of five and the cause of serious illness in the elderly.
Lewis: That’s Bernie Graham.
Graham: I am currently Senior Advisor for Global Health Equities at Morehouse School of Medicine in Atlanta. Previously, he was Associate Director of the NIH’s Center for Vaccine Research in Bethesda.
Lewis: You may have heard of him primarily because he and a team of scientists at NIH’s Center for Vaccine Research contributed to the technical development of mRNA COVID vaccines.
Fishman: He was actually working on an RSV vaccine when the pandemic hit and turned to COVID. His team’s commitment to these shots changed the world and protected millions of people.
And the scientists ended up on the cover of TIME magazine. But RSV has never left Graham’s mind.
Lewis: RSV was discovered in 1956, about the same time the first polio vaccine was developed.
Scientists began researching an RSV vaccine in the early 1960s. However, these early efforts were marred by some serious problems.
Like the polio vaccine, the first RSV vaccine was based on a completely inactivated virus. A clinical trial in 1965 tested children under 6 months of age.
But the problems started that winter —
[CLIP: Music]
Graham: …that vaccine, that whole inactivated vaccine, was tested in about 31 children compared to another control group. But the next winter season, right after Christmas, during the 66th, 67th minute, 20 out of 31 of the 31 children were infected, 16 out of 20 needed to go to the hospital, and 2 of them person died.
Lewis: It was really a terrible tragedy.First of all, the vaccine enhanced Because the severity of the disease caused the wrong kind of immune response in children. Graham started his RSV career wanting to understand why—
Graham: For 20 years I have been wondering what causes vaccine-enhanced diseases?
Lewis: Graham started working with scientists Jason McClellan and Peter Kwon to design a better RSV vaccine.
RSV uses a protein called the “F glycoprotein” to infect cells. Upon fusion with the host cell, the protein “unwinds” from its so-called pre-fusion form, grabs onto the cell membrane, and then “refolds” into its post-fusion form.
Early vaccines failed because they were based on a post-fusion morphology.Therefore, when given to children, their bodies produced antibodies that only weakly attacked the pre-fused form. more Serious and nothing less.
Fishman: Wait a minute. It turns out that there are pre-fusion and post-fusion morphologies. What I don’t quite understand is why this whole vaccination process makes the disease more serious than a “no vaccine” condition.
Lewis: that’s a great question. Antibodies targeting the post-fusion form still elicited an immune response, but it was a rather hyperinflammatory state, which proved dangerous. I turned my attention to doing
Graham: Once we had that structure and learned how to stabilize it and maintain its shape, it turned out to be a very good vaccine antigen.
Lewis: That brings us to today. Several companies are now developing vaccines using this protein structure-based approach.
Both Pfizer and GSK are testing vaccines for adults over 60 and for pregnant women, which can protect babies up to six months of age. And some of these, especially those for the elderly, appear to be nearing FDA approval.
And it’s not just vaccines. For children under 6 months, who are most susceptible to severe infections, several companies are also producing monoclonal antibodies against her RSV.
A product called Nirsevimab, manufactured by AstraZeneca, has already been approved in Europe and is undergoing US FDA review.
Graham: It’s exciting and satisfying for us. We plan to have a product for RSV as several are in very advanced development or close to licensing.
Lewis: Graham said the FDA will likely make decisions on antibody products and some vaccines for the elderly by July, or even sooner.
Fishman: In fact, just a few weeks ago, the FDA’s panel of independent medical advisors met to review the latest data on two RSV vaccines in older age groups.
Their information comes from the exams you mentioned and others.
Lewis: Overall, the effectiveness rate was very impressive. GSK’s vaccine was about 83% effective in preventing lower respiratory tract infections in adults over the age of 60, and he was 94% effective in preventing severe illness. On the other hand, Pfizer’s vaccine was 67% effective in preventing infection and 86% effective in preventing severe disease.
But that’s not all.
Fishman: No, it’s not. I looked at the FDA’s advisory committee, and the committee wasn’t entirely satisfied.
[Start CLIP: FDA Advisory Audio]
Unidentified Doctor: The public is very skeptical, and in order to preserve, and perhaps rebuild, the trust that the FDA earns from the public, we really need to be careful about vaccine safety before we ship it.
[End CLIP: FDA Advisory Audio]
They were worried about two sudden side effects.
Fishman: One is called acute disseminated encephalomyelitis. That’s when the brain and spinal cord swell up rapidly. In his GSK vaccine trial of about 15,000 people he had two cases.
Lewis: Another concern was Guillain-Barre Syndrome. Guillain-Barré syndrome is a rare neurological disorder that causes weakness and sometimes paralysis. It usually starts in the limbs and spreads throughout the body.
Fishman: Yes, it happened to one person who got the GSK vaccine and two who got the Pfizer vaccine. What is concerning is that these conditions do not occur very frequently in the general population.
So the trial may have something to do with vaccines. And that really bothered FDA advisers.
Lewis: However, it is also possible that these cases were accidental. One or two cases are too few to tell if there is a real safety issue.
Meanwhile, a trial of the GSK maternal RSV vaccine was halted due to safety signals. That means we also saw some side effects that need to be investigated further. Pfizer’s maternal vaccine trials are still ongoing.
Fishman: Ultimately, advisors voted to proceed with the application for a vaccine for the elderly. That will take months, and scientists are eager to see more safety data as these trials continue.
Therefore, the RSV vaccine is not a completed deal. But things are probably heading towards approval.
Lewis: yeah i bet on that. We’re also watching what’s happening with antibody products for young children and vaccines for mothers: RSV is still a serious disease for small babies.
Writer Tara Haelle has written an online news story for us about the long road to an RSV vaccine.
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Lewis: Thank you for listening!
fishman: Your Health Quickly is written and edited by Tulika Bose, Jeff Delviscio, and Kelso Harper.
Lewis: Shaw is one of them of Scientific American Science, quickly podcast. Quickly subscribe to Science wherever podcasts are available.
fishman: And don’t forget to visit Sciam.com for updated and in-depth health news.
Lewis: I’ll be back in two weeks. Then talk!
