How scientists vaccinate against variants

BURLINGTON, Vt. (WCAX) - Some experts are predicting the current COVID vaccines will be less effective against the emerging omicron variant. So what happens then?

Most scientists are warning it’s too early to tell whether the shots that millions of people have already gotten will hold up to the omicron strain. But just in case, Moderna and Pfizer say they could have a new vaccine ready in about three months.

Scientists say the omicron variant is a heavily mutated strain of COVID-19. “Because there’s so much of this virus out there, it’s in so many people, and in some people it lasts for a long time, and it replicates -- mistakes get made,” said Dr. Beth Kirkpatrick, director of the University of Vermont’s Vaccine Testing Center at the Larner College of Medicine

She says those mistakes become part of the virus’ genetic sequence and established vaccines may not recognize and therefore can’t attack the virus’ spike protein. “The spike protein is what allows that virus to stick to a human cell and then get into the human cell,” Kirkpatrick explained. “A vaccine will prompt lots of antibodies but these are key antibodies that then will glom up the virus, so that then that spike protein cannot stick to your cell and cannot get in the cell.” That’s what stops the infection from spreading.

Companies right now are working around the clock to determine if the vaccine they’ve already developed will produce the antibodies needed to fight omicron. If they don’t, it’s time to design a different version. “What they do is they find that virus in somebody’s clinical sample and then they pull out the genetic material and they run it through a machine that can tell you the genetic sequence. And once they can tell you the genetic sequence, that information -- now you know, here’s the sequence of that new mutated spike protein,” Kirkpatrick said.

Scientists can take the existing vaccine’s genetic sequence and swap it out with the variant’s. “So once you’ve got the new vaccine designed, the challenge of getting it to scale is pretty large. I mean, you just have to get so much of these vaccines made in such purity,” Kirkpatrick said.

Researchers then have to prove the new vaccine is not only effective but safe. Kirkpatrick predicts widespread distribution probably won’t be necessary but that we simply don’t know what we’re dealing with yet. “I think the jury is really still out on that. It’s so early and we know these have characteristics, these mutations, that looks like it’s going to be more transmissible, but we don’t know if it’s going to be more severe and we don’t know if the other vaccines won’t work,” she said.

Government officials and scientists say we can count on waiting a few weeks for those conclusions.

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