Omicron-based Covid booster shots will be launched this fall

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This fall, vaccine manufacturers will begin rolling out booster coronavirus vaccines that are better tailored to combat the current phase of the pandemic.

Two days after outside experts voted for a new vaccine capable of protecting against Omicron, the Food and Drug Administration announced the case shots would contain a component of BA.4 and BA.5, the Omicron subvariants that gaining ground in the United States.

The change shows the FDA is trying to be more nimble in its efforts to keep up with a changing virus. The exact formula has not yet been tested in humans, but studies showed that vaccines designed to target an earlier version of Omicron slightly increased the short-term immune response in humans compared to more shots of the original. The agency will rely in part on this data when reviewing the new vaccines.

The FDA on Thursday advised companies to develop a two-part vaccine for a fall booster campaign. Part of the vaccine will be the original formula based on the version of the virus that spread around the world in early 2020. The other part will be based on the Omicron subvariants BA.4 and BA.5, which currently account for half of the strains being sequenced in the US.

It’s entirely possible that BA.4 and BA.5 will be eclipsed by new variants by the fall, but the hope is that a new vaccine will help expand immunity as they’re closer to the spot , where the virus is located today. A Pfizer scientist showed data to FDA advisers on Tuesday that a vaccine based on these Omicron versions appeared to produce a stronger immune response in mice.

Tracking of the coronavirus vaccine

For the past year and a half, coronavirus vaccines based on the original version of the virus have offered robust protection, especially against serious illnesses. But immunity wanes over time, and the virus has shown itself to be cunning, spawning a burgeoning Greek alphabet of new variants that are more contagious and adept at bypassing people’s immune defenses.

“As we approach autumn and winter, it is critical that we have safe and effective vaccine boosters that can provide protection against circulating and emerging variants to prevent the most severe consequences of Covid-19,” it said in the FDA statement.

Experts were concerned that such a consistent decision would have to be made on the basis of very limited data. It is possible that the change will noticeably increase the protection of people against serious illnesses and perhaps also infections, but it is not certain.

“I think the FDA here is taking their best guess as to what they think is right, and that may or may not turn out well,” said John Moore, professor of microbiology and immunology at Weill-Cornell Medicine. “We don’t know and have no real way of knowing.”

The modified vaccine is used as a booster dose. People who are still receiving their first vaccinations will continue to receive the original version of the vaccine.

People who are unvaccinated or unboosted shouldn’t delay getting vaccinated in hopes of getting a new shot, especially given the high rates of transmission, said an FDA official, who requested anonymity because they weren’t authorized to speak . People may still be eligible for the boost in the fall, and all vaccines offer the best protection against serious illness and hospitalization.

The federal government announced Thursday that it had agreed to buy 105 million doses of Pfizer’s newly launched vaccine for $3.2 billion. At $30.50 per dose, that’s a premium over the original contracts the government made for the original vaccine in 2020, when the vaccines cost $19.50 per dose.

Pfizer has said the price of its vaccine is likely to increase post-pandemic, and that may not be the upper limit.

“We anticipate that this is only the second price step between pandemic prices and future commercial prices,” analysts at SVB Securities Research wrote in a note analyzing the announcement.

Moderna President Stephen Hoge told an FDA advisory committee that it would take his company until late October or early November to develop a vaccine based on Omicron’s BA.4 and BA.5 versions. It was unclear Thursday what the company’s timeline would be to ship revised cans to the United States.