Lewis asked: Hi and welcome to COVID, Hurry, a American Scientist podcast series!
Josh Fishman: This is your expedited update on the COVID pandemic. We inform you about the science behind the most pressing questions about the virus and the disease. We demystify research and help you understand what it really means.
Lewis: I am Tanya Lewis.
fisherman : I am Josh Fischman.
Lewis: And we’re the health editors of Scientific American. Today we are going to discuss the new alphabet soup of variants and sub-variants likely to be around this winter…
fisherman : And we’ll talk about how boosters add protection even if you’ve already had COVID.
fisherman : We are heading into another pandemic winter. Although no completely new variants of the COVID virus have yet emerged, there are several new sub-variants of Omicron. You call them Halloween Scariants, Tanya. What do we know so far?
Lewis: The Omicron variant first appeared last fall, and over the past year, COVID cases have mostly been caused by different versions of Omicron. First there was B.1.1.529. Then there was BA.1, BA.2 and BA.3, then BA.4 and BA.5.
Now there are new kids in the neighborhood: There’s BA.4.6, which descends from BA.4 and accounts for about 12% of COVID cases in the US And there’s BQ.1 and BQ.1.1, which together account for more than 11 percent of cases, according to the CDC’s Variant Tracker. And these proportions continue to grow.
Meanwhile, in Singapore, a subvariant called XBB has led to an increase in cases and may be the most immune-evasive variant we’ve seen to date.
fisherman : So at least 4 beginners. How worried should we be?
Lewis: Anthony Fauci, Biden’s chief medical adviser, called them “embarrassing.” Like other variants before them, they grow rapidly. And at least in the case of BQ.1.1, it seems to be more effective at evading our immunity to previous infection or vaccination, although vaccines should still offer protection.
Another concern is monoclonal antibody treatments, as we discussed on the last show. The one given prophylactically to immunocompromised people, known as Evusheld, is not effective against the BA.4.6 variant. And another antibody called Bebtelovimab, of which the United States has already ordered 60,000 doses, is not effective against BQ.1, the FDA said.
fisherman : This is bad news for people whose immune systems cannot generate a strong response to vaccines.
Lewis: It’s true. Biden administration officials are in talks to develop alternatives, but it’s unclear whether those will arrive in time for a winter push.
fisherman : Do the experts think we’re headed for another push? And what role will the new variants play?
Lewis: COVID cases are already on the rise in Europe, which is usually a few weeks ahead of the United States. So I would say that there is a good chance that we will see a new surge. But that was happening before the new variants even hit the scene. So some people think variants will only speed things up.
fisherman : So how can people protect themselves?
Lewis: The best thing you can do is get vaccinated. The new bivalent booster protects you against both the original SARS-CoV-2 strain and Omicron’s BA.4 and BA.5 subvariants, and is also likely to provide some protection against the new variants . Yet a few weeks ago, only about 5% of eligible people in the United States had been vaccinated.
fisherman : This leaves many people unprotected.
Lewis: It does. And many young children have not even been vaccinated at all. But there’s still time to get one before the holidays, or the turkey might not be the only thing on the dinner table.
Lewis: We were just talking about how few people get new booster shots. There are many possible reasons. Many people are no longer worried about COVID, and more and more have already caught it and recovered. Some may think they now have natural immunity to new infections. Do they?
fisherman : Kind of. I mean, yes, natural immunity is a real thing. But research shows it’s not as strong as what scientists now call “hybrid immunity,” which is an older infection plus a new booster.
Lewis: Does this mean that people who have been infected in the past AND who have received a vaccine have better protection?
fisherman : Yeah. Some of the best data on this comes from a large study done in Qatar and published this summer in the New England Journal of Medicine. He followed about 150,000 people. Qatar has a very strong system of national health records. Thus, the researchers were able to tell who was infected or re-infected with Omicron and when. And they had records of those who had been vaccinated with the Pfizer or Moderna vaccines, or who had not been vaccinated at all.
Lewis: Did they find significant differences?
fisherman : They did it. First, unvaccinated people had the highest risk of infection, and that’s not really a surprise. People with a previous infection reduced their risk of re-infection by about 50%.
And people who only had the original two-shot regimen had a similar risk. Scientists think it’s because people got these vaccines about 8 months earlier, so their immunity went down.
The big advantage, however, went to people who had a previous infection more Three strokes. These are the original two shots plus an encore. This reduced the chances of re-infection by about 80%. And that was true for the Pfizer and Moderna vaccines.
Lewis: This is a really striking advantage. Has it withstood severe disease, keeping people out of hospital and reducing death rates?
fisherman : It made. Hybrid immunity like this prevented severe disease, again by about 80%.
Lewis: Even in people who have never been infected, a booster shot helps.
fisherman : Yes, it reduces many of your symptoms. And as someone who was recently immobilized by COVID for two weeks, I can tell you that fewer symptoms is a big deal.
The recall data comes from a different study, a 5-month review of about 1100 healthcare workers, which just appeared in the journal JAMA. Those who received a booster, in addition to the initial two injections, were less likely to experience fever or chills if infected with Omicron. They were less likely to need medical attention and could take care of themselves at home. They also missed fewer hours of work. All of this is compared to people who were not vaccinated at all.
Lewis: Do recalls do anything against the risk of transmission? The chances of transmitting the infection to other people?
fisherman : They seem to help. They dropped the viral load – the amount of virus you have in your body – by about a third, compared to unvaccinated people. Now, a lower viral load does not automatically equate to less transmission, the scientists noted. But other studies have made this connection.
And about 20% of people infected with Omicron in this study had no symptoms, so they didn’t know they had the virus and were probably hanging out with other people.
Lewis: This in itself therefore increases the risk of transmission.
fisherman : It does. Boosters therefore help in several ways. And, as you said, now is the time to go out and get one.
Lewis: Now you know. Thanks for join us. Our show is produced by Jeff Delviscio and Tulika Bose.
fisherman : Check back in two weeks for the next episode of COVID, Hurry! And check sciam.com for updated and in-depth COVID news.
[The above text is a transcript of this podcast.]