Scientists are working on booster shots when the COVID-19 vaccine is ineffectiveExBulletin

Mary Louise Kelly, Host:

The COVID vaccine available in the United States today is very effective in preventing disease, but it remains to be seen how long the prevention will last and whether it will be effective against potential viral variants. I have a question. Therefore, as reported by NPR’s Joe Parka, researchers have come up with strategies to boost existing vaccines.

JOE PALCA, BYLINE: The current crop of COVID vaccines works by encouraging people’s immune system to make antibodies against the virus, allowing it to be repelled when exposed to the virus. Mark Denison, a virologist at Vanderbilt University, states that the levels of antibodies produced in this way usually decrease over time, reducing the protection provided by vaccination. It’s happening with the COVID vaccine.

Mark Denison: I was frankly impressed with how slowly antibody levels were declining and that protection could be at lower levels than we expected or expected. That we are defenseless.

Parka: That’s good news. However, they are still declining and eventually their vaccine protection may expire. I’m not there yet, but it’s wise to prepare. Another challenge is mutations in a major viral component called peplomer. This can lead to variants of the virus where existing vaccines are unable to produce suitable antibodies. Denison says boosters can address both possibilities.

Denison: What Booster does is to present a new version of Virus Spike. This has the potential to amplify what we already have and expand the variety of antibodies we have.

PALCA: But before you create a booster that can handle new variants, there are some important things you need to know.

NADINE ROUPHAEL: One is to understand the variants we are dealing with.

PALCA: Nadine Rouphael is the director of the Hope Clinic at the Emory Vaccine Center. She says it doesn’t make sense to give Americans a vaccine designed for a South African variant, for example, if it’s not in circulation here. In some cases, it may be sufficient to raise antibody levels with the original vaccine. Higher antibody levels may be able to handle most, if not all, mutants. She is testing both possibilities with a new vaccine from Moderna.

ROUPHAEL: Either the original vaccine Boost, the variant vaccine Boost, or a mixture of both.

PALCA: There is a big problem if researchers decide that they need a new vaccine to deal with a new variant. How does the Food and Drug Administration determine the types of tests needed to show that a new vaccine is safe and effective? The current crop of the vaccine has been tested using a large study of tens of thousands of people to see if the vaccine really prevented COVID disease. If a new vaccine is urgently needed, it will take too long. Peter Gilbert of the Fred Hutchinson Cancer Research Center is leading an effort to test vaccines using blood samples.

Peter Gilbert: A blood sample that can be used to reliably predict that a vaccine will prevent COVID without having to measure whether a person is infected with COVID.

Parka: Gilbert says blood tests are ready in a few weeks. Mark Denison of Vanderbilt says you shouldn’t think about it because you may need a booster, vaccines are not an effective tool for dealing with a COVID pandemic.

Denison: I think it reflects the reality of biology, so if you need it, I’m okay with a booster. This is not a fairyland. This is not magic. It’s true biology.

Parka: Denison says the COVID pandemic can be thought of as a chess game-human vs. virus. By mutating into a new form, the virus may be able to break away from our human attempts to suppress it.

Denison: Indicates that the chess movement is ready. It still has a chess move to do. However, the movement of chess still remains.

Parka: And to maintain the chess analogy, we could enter a long end. Joe Parka, NPR News.

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