Analysis: The next COVID booster shots are likely to be updated for Omicron

The test tube labeled “COVID-19 Omicron variant test positive” is seen in this illustrative image taken on January 15, 2022. REUTERS/Dado Ruvic/Illustration

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NEW YORK, June 24 (Reuters) – COVID-19 vaccines this fall are likely to be based on the Omicron variant of the coronavirus rather than the original strain, although some experts suggest they may only offer significant benefits to the elderly and immunocompromised .

Moderna (MRNA.O), Pfizer (PFE.N) and Novavax (NVAX.O) have tested vaccines based on the first BA.1 omicron variant, which became dominant last winter and caused a massive surge in infections .

On Wednesday, Moderna said its updated vaccine against newer Omicron subvariants is working well and that it is moving forward with plans to seek regulatory approval. Continue reading

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Vaccines that can bridge the gap between the original version of the coronavirus and the Omicron variant would likely be “far, far better” by fall, according to Trevor Bedford, a biologist at the University of Washington who tracks mutations in the SARS virus has pursued. coV-2 virus.

Bedford said it would take too long to meet regulatory requirements for a switch to tailor the next vaccine to versions of Omicron that are now spreading rapidly.

“It’s really important to catch up with one of the omicrons,” he said, noting the huge increase in the number of mutations from the original strain introduced in China to omicron on the spike protein part of the virus that the vaccines target. showed up.

The World Health Organization (WHO) plans to evaluate the effectiveness of vaccines made for Omicron, as will national health agencies such as the US Food and Drug Administration.

A group of WHO advisers said last week that an Omicron-based vaccine could extend immunity after the Omicron variant bypassed much of the protection against infection generated by vaccines developed for the original virus, a view that other experts share. The FDA’s scientific advisors will meet on June 28 to make a recommendation on the matter.

Important questions remain, including whether vaccines developed for variants that were circulating last winter will work well against significantly different subvariants that may arise. Experts also want to know whether the new shots will increase protection from serious illness and death for younger, healthier people, or just provide a few months extra protection from a mild infection.

Scientists who have questioned the value of booster shots for the young and healthy say a broad campaign with an updated shot isn’t necessary either.


In contrast to annual adjustments for influenza vaccines, which manufacturers are allowed to try to adapt to circulating strains, regulators have urged companies to conduct clinical trials to prove their new COVID vaccines work better.

But nearly three years into the pandemic, vaccine makers are pushing for a flu-like model that would allow them to quickly switch their immunizations to target new variants.

At stake are contracts worth billions with countries around the world. Moderna is already making the shots, with deals signed in some countries.

Moderna is asking regulators to give the green light to a version of their COVID-19 shot that targets both the BA.1 Omicron variant and the original version of the virus, armed with new evidence that it may be effective against newer subvariants is effective.

“The challenge we face is that the virus is evolving very rapidly,” Moderna President Stephen Hoge said in an interview, noting that millions of doses of the updated vaccine could be ready by August.

If the drugmaker needs to continue optimizing the vaccine and restart manufacturing, new shots may not be available until mid-fourth quarter, he said.

Pfizer and its partner BioNTech (22UAy.DE) are testing variant-adapted COVID-19 vaccines but have not yet published any data. Novavax, whose vaccine is not yet approved for use in the United States, began a trial of its own Omicron-based vaccines in late May.

dr Jesse Goodman, a professor at Georgetown School of Medicine and a former top FDA scientist, said that unlike the flu, regulators don’t have enough experience with COVID vaccines to adapt them to circulating strains without clinical trials.

dr Luciana Borio, a former FDA acting chief scientist, said science generally supports the idea that it would be better to have vaccines that better match the virus currently circulating.

“We see that in people who have hybrid immunity to vaccination plus infection,” Borio said. “The generated immune response is very rich.”

Still, Borio and others aren’t convinced everyone should be revaccinated.

“There is no evidence that a healthy 27-year-old person needs to be re-vaccinated,” Borio said.

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Reporting by Michael Erman Editing by Caroline Humer and Bill Berkrot

Our standards: The Thomson Reuters Trust Principles.

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