If an omicron vaccine is needed, how long would it take to develop one?

If it turns out vaccines need to be adjusted to target the new omicron variant of SARS-CoV-2, a University of Virginia infectious diseases expert said it could be done quite quickly.

It’s about how messenger RNA vaccines, such as the COVID-19 vaccines, work.

“It’s very, very simple to change a single mRNA molecule so that your vaccine now is effective against the most recent variant,” said Dr. Bill Petri, chief of the Division of Infectious Diseases and International Health at the university.

Because of the way mRNA vaccines work using parts of the human genome, Petri said it doesn’t matter that the omicron variant has more than twice the mutations of delta, compared with the original virus.

“That’s the beauty of messenger RNA, because it’ll encode all of the mutations — the host cells, the human cells. And when the vaccine is injected, it will make the spike protein that is identical to the omicron spike,” he said.

The World Health Organization is coordinating with researchers around the world to better understand omicron. Its website says studies are underway or will get started shortly, including assessments on the performance of vaccines and diagnostic tests; transmissibility; severity of infection, including symptoms; and effectiveness of treatments.

If it turns out an omicron-specific vaccine is needed, it could take six months to a year for one to be ready for widespread distribution, after an abbreviated set of clinical trials similar to what’s happening with expansions of vaccine eligibility for children, Petri said.

“Six months to a year to have a new vaccine sounds really slow with the rapid, fast pace of advancement with COVID-19. But that’s way faster than if we had to start from scratch with a more traditional protein-based vaccine, and we’d be talking years to retool things,” Petri said.

While it remains unclear what a future with omicron might involve, Petri said people should be most worried about the delta variant.

“It came in March, and it totally replaced all the other variants. And that caused a huge peak in new COVID infections in September. And it’s less than it was in September, but it’s plateaued. So it’s not improving; it’s not getting worse. We all expect that even if it stays at its current level, this is going to have a major impact on public health,” Petri warned.

Everyone should be concerned about their vaccination status, he said.

“Everyone 5 years of age and older should be vaccinated, because that will protect against delta; it likely will protect against omicron. And if you’ve been vaccinated two months ago with Johnson & Johnson — or six months ago with Pfizer or Moderna — get the booster as well, because that’s very, very important for providing optimal protection.”

Now is also the time for a flu shot, he said, if you’re not inoculated already.

Kristi King

Kristi King is a veteran reporter who has been working in the WTOP newsroom since 1990. She covers everything from breaking news to consumer concerns and the latest medical developments.

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