WSince nearly all new COVID-19 infections in the United States come from Omicron BA.4 and BA.5 sub variants, it makes sense for health officials to consider switching to a different vaccine to protect the public.
White House COVID-19 Response Coordinator Dr Ashish Jha expect The first Omicron booster will be available in mid-September at the earliest, if the US Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) have recommended the injection. In late August, both Pfizer-Biwantech And the Moderna Submit applications to the Food and Drug Administration for authorization of their Omicron enhancers.
But with fall and winter fast approaching — the seasons when respiratory viruses like SARS-CoV-2 spread more efficiently, students return to school and people gather indoors — equipping the booster requires a more efficient review and regulatory process. This includes looking at safety and efficacy data from animals, not humans.
Back in June, it was An FDA panel of independent vaccine experts met To consider switching the country to a new booster targeting Omicron, given how quickly this alternative is dominating new infections. At the time, Pfizer-BioNTech and Moderna — which make mRNA-based vaccines — the two largest manufacturers of COVID-19 vaccines, both developed shots against an earlier variant of Omicron, BA.1. The committee decided that if the health authorities were to change the booster shot to target Omicron, the next shot should protect against the BA.4 and BA.5 sub variants, which would continue to account for nearly all cases in the winter.
They asked vaccine manufacturers to develop a new vaccine, which combines the original vaccine and also targets Omicron BA.4 and BA.5. At the end of August, both companies submitted data on their new bivalent vaccines to the US Food and Drug Administration for emergency use authorization.
However, due to the short time they had to develop the shot, the data included only information about the safety and effectiveness of the reinforcer in animals. Human studies are planned and will continue even if the Food and Drug Administration and the CDC decide to authorize the shots and the government begins distributing them. The FDA also decided to review the animal study data without consulting its advisory committee again.
This has divided vaccine experts. Dr. Paul Offit, a member of the advisory committee, says this strategy makes him “uncomfortable” for several reasons. He notes that data provided by Pfizer-BioNTech and Moderna in June including a BA.1 booster dose, which focused on levels of virus-fighting antibodies produced by the vaccine, was disappointing. “They showed that the neutralizing antibody titer was 1.5 to two times higher against Omicron than levels induced by a progenitor-boosted vaccine,” he says. “I would like to see clear evidence of a massive increase in neutralizing antibodies, more dramatic than what we saw against BA.1, prior to launching a new product. We owe that at least.”
While human studies are taking longer, Offit says that even a small trial involving about 100 people to measure their antibody levels after getting a BA.4/5 booster would be beneficial. “You can boost people and measure their antibodies after two weeks,” he says. This information can also be crucial in setting realistic expectations for the Omicron booster. The public may feel that it is a panacea that signals the end of the pandemic, but without any data showing how well the enhanced protection will protect people not only from getting sick, there may be unrealistic expectations about what such a boost can do. “Honestly I feel a little nervous when I hear this [booster] Offit says.
Other experts see it a little differently. Based on the fact that mRNA vaccines have been administered to millions of people to date, with relatively few safety concerns, and given that vaccines have been effective in protecting people from hospitalization or death from COVID-19, even during the most recent release of Omicron. , they argue that changing the virus strain in a vaccine does not require the same extensive testing that the original shot did. “The entirety of the evidence is relevant here,” says Dr. Ofer Levy, director of the Microvaccine Program at Boston Children’s Hospital and a member of the Food and Drug Administration’s Vaccine Advisory Committee. “We’re in a situation where we need to pivot as the variables come up, and if we try to be too strict in our approach we’ll always be behind, and not optimally protect the population.”
Levy says that the latest Omicron-specific boosters that the FDA is considering contain a combination of mRNA targets against both the original virus and Omicron BA.4/BA.5, so data on safety and efficacy from the original vaccine in protecting against hospitalization and death are important. . While the data on this vaccine comes from animals, using that data to decide whether or not to authorize a booster is a matter of “prudential bets.” There is data showing that even people who have been vaccinated and boosters can develop mild to moderate COVID-19 disease, because vaccine-induced protection is diminished, so a boost in a dose that best matches the now circulating Omicron sub-variables is a reasonable bet, even if the data on Their effectiveness comes from animals, not humans. “I think it’s the right decision,” Levy says.
There is no guarantee that the FDA will approve the new bivalent vaccines, although all signs indicate an authorization may come in a week or so. If the shots are released and people are boosted, health officials will carefully monitor the data from those vaccines to ensure the assumptions they have made about the safety and effectiveness of the booster nodes. Hospitalization rates next winter will reveal whether betting on Omicron’s new booster is the right decision.
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