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WASHINGTON — The Food and Drug Administration on Wednesday authorized the first redesign of coronavirus vaccines since they were rolled out in late 2020, setting up millions of Americans to receive new booster doses targeting Omicron subvariants as soon as next week. The agency cleared two options aimed at the BA.5 variant of Omicron that is now dominant: one made by Pfizer and its German partner BioNTech for use in people as young as 12, and the other by Moderna, for those 18 and older. The doses can be given at least two months since people last received a booster dose or completed their initial series of vaccinations. Biden administration officials have argued that even as researchers work to understand how protective the new shots might be, inoculating Americans again in the coming weeks could help curb the persistently high number of infections and deaths. “As we head into fall and begin to spend more time indoors, we strongly encourage anyone who is eligible to consider receiving a booster dose,” Dr. Robert M. Califf, the F.D.A. commissioner, said in a statement on Wednesday. He added that the vaccine would “provide better protection against currently circulating variants.” An average of about 90,000 infections and 475 deaths are recorded every day around the United States, almost three years into a pandemic that has killed more than a million Americans and driven a historic drop in life expectancy. But there are also hopeful signs. Even with high case counts, fewer than 40,000 people are currently hospitalized with the virus, a decrease of 10 percent since early August and far fewer than during the Delta-driven surge last summer or the Omicron-fueled wave last winter. Deaths have also remained somewhat flat in recent weeks, a sign that vaccines are helping to prevent the worst outcomes of Covid-19. Ample evidence suggests that many Americans will hold back from getting the updated boosters, either because they are weary of the pandemic or may not feel urgency about an additional dose. With each new shot offered, there are fewer takers. As more companies bring workers back to offices and students return to campuses this fall, persuading Americans to get the updated booster shots will be a major challenge for the administration. The companies produced the retooled shots with extraordinary speed, a testament to the mRNA technology that Pfizer and Moderna have harnessed since the early months of the coronavirus outbreak. The Food and Drug Administration advised companies only two months ago on the formulation that they should adopt for the new vaccines. By later this week, millions of those doses will be delivered to states. The tight timeline meant that the companies went to federal regulators this summer with more limited data on the redesigned boosters than a traditional review process would call for, generating some controversy. Regulators authorized the vaccine without results from human trials, which have just started. Federal officials argue that because the coronavirus is evolving so quickly, human trials would be out of date before they can deliver results that could be used in the F.D.A.’s authorization decision. Instead, they are relying on the results of mouse trials and earlier human trials by Pfizer and Moderna of reformulations aimed at previous versions of the virus. The Biden administration is casting the shots as a standard upgrade that Americans should embrace ahead of potential surges in cases in the winter, like the flu shot, which is reconfigured every year to target more current versions of the influenza virus. The boosters are arriving during a period when the White House has been largely quiet on the pandemic. President Biden has rarely commented on the coronavirus in recent months, even after he tested positive in July. The White House no longer holds regular news briefings on the federal pandemic response, as it did in the first year of the administration — a reflection of the weariness of many Americans in keeping up with Covid precautions. “Covid-19 is the third leading cause of death in the United States. And it’s as if we’ve just accepted that that is going to be the case,” said Mercedes Carnethon, an epidemiologist at Northwestern University’s Feinberg School of Medicine. “I really hope as many people as possible will seek the updated booster so we can protect those who will have a terrible outcome.” Vaccinations remain the cornerstone of the federal government’s Covid strategy, even with tests and treatments widely available. The Biden administration has ordered over 170 million doses for the fall campaign, and officials do not expect shortages when they are rolled out. “If it’s freezing cold out and you have children, you’re going to dress them warmly. This is the concept here,” said Dr. Paul G. Auwaerter, the clinical director of the infectious diseases division at the Johns Hopkins University School of Medicine. “You’ll want to head into the respiratory season with a virus that we know has surprised us with a booster.” Exactly how protective the shots might be is unknown, Dr. Auwaerter said. He pointed to the modest increases in neutralizing antibodies that the companies found in vaccines they tested this year that targeted the original form of Omicron. How antibody levels would translate to protection with the new vaccines was unclear, he added. Experts warned against trying to choose Moderna’s shot over Pfizer’s or vice versa; with research in humans just beginning, scientists are months from knowing whether one brand offers better protection than the other. Many Americans have recently been infected with variants in the Omicron family and have some protection from their bouts with the virus, a development that federal agencies may take into account when recommending how the new shots are used. An advisory committee to the Centers for Disease Control and Prevention is scheduled to meet this week to make recommendations. “For most people, the risk of death is so low at this point, because they’ve gotten infected or vaccinated, or more likely both,” said Dr. Gregory A. Poland, a professor of medicine and infectious diseases and the director of the Vaccine Research Group at the Mayo Clinic. Dr. Poland, who has advised Moderna, Pfizer and White House officials on coronavirus vaccines, said updating booster shots the way the Food and Drug Administration did on Wednesday amounted to a “chase your tail” strategy, tweaking the design incrementally to try to keep up with a fast-changing virus. The new boosters, he said, could potentially save some lives among the elderly and those with immune deficiencies. But they were unlikely to make as substantial an impact with the rest of the population.
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Juan Lama
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Updating the shots to target omicron could provide more durable protection against the virus, though current supporting data is limited. - Omicron is continuing to evolve into more contagious subvariants.
- Dr. Peter Marks, who heads the FDA’s vaccine division, said the U.S. faces a Covid outbreak this fall as immunity from the vaccines wanes and people spend more time indoors.
- Updating the shots to target omicron could provide more durable protection against the virus, though current supporting data is limited.
The Food and Drug Administration’s panel of independent vaccine experts on Tuesday voted 19 to 2 to recommend new Covid-19 shots that target the omicron variant this fall, when public health officials are expecting a new wave of infections. It is the first time the panel has proposed that vaccine makers modify the shots to target a different variant. The FDA will likely accept the committee’s recommendation and authorize a vaccine change. However, the panel did not make a recommendation on which omicron subvariant the shots should target. Pfizer, Moderna, Novavax and Johnson & Johnson all developed their vaccines against the original Covid strain that first emerged in Wuhan, China, in 2019. But as the virus has rapidly evolved over the course of the pandemic, the vaccines have become less effective at protecting against infection and mild illness, though they are still generally protecting against severe disease. The vaccines target the spike protein the virus uses to invade human cells. However, the shots have trouble recognizing and attacking the spike the more it mutates away from the original version of the virus. The omicron variant is the most dramatic example yet with more than 30 mutations. That is one of the central reasons why omicron caused such a massive wave of infections last winter despite the fact that masses of people were fully vaccinated. Fall booster campaign Omicron continues to mutate into more contagious subvariants. Dr. Peter Marks, who heads the FDA’s vaccine division, said the U.S. faces a Covid outbreak this fall and winter as the virus evolves, vaccine immunity wanes and people spend more time indoors where Covid can spread much easier than outdoors. “For that reason, we have to give serious consideration to a booster campaign this fall to help protect us,” Marks told the committee. “The better the match of the vaccine to the circulating strain, we believe may correspond to improved vaccine effectiveness and potentially to a better durability of protection.” Justin Lessler, an epidemiologist at University of North Carolina Chapel Hill, said 95,000 additional people could die in the U.S. from Covid by March 2023 in the most optimistic projections from a team of scientists who are developing models of the pandemic’s trajectory. In the most pessimistic scenario, 211,000 people could perish from the virus by March of next year, he said. However, Lessler cautioned that there is a lot of uncertainty in those projections. Three doses from the current vaccines are just 19% effective at preventing infection from omicron among adults ages 18 and older 150 days or more after administration, according to data presented by the Centers for Disease Control and Prevention. This low protection against infection is likely due to omicron evolving into the more contagious BA.2 and BA.2.12.1 subvariants, CDC official Dr. Ruth Link-Gelles said. A third dose was 55% effective at preventing hospitalization from these subvariants among adults 120 days or more after receiving the shot, according to the data. Limited data, limited time The virus is evolving so quickly that the vaccine companies are struggling to keep up. Pfizer and Moderna developed their omicron shots against the original version of the variant, BA.1. However, BA.1 is no longer circulating in the U.S. A more contagious omicron subvariant, BA.2, became dominant over the spring. The omicron subvariants BA.4 and BA.5 are now rapidly gaining ground in the U.S. and are poised to become dominant, Marks said. Pfizer and Moderna presented data, based on small studies of several hundred people, showing their omicron shots significantly boosted the immune response against omicron BA.1 compared to the original shots that targeted the virus strain that emerged in China. However, the updated shots did not perform as well against BA.4 and BA.5, though the immune response was still strong. There is no available data on the real world effectiveness of the updated shots, though the strength of the immune response is generally viewed as an indication of how much protection the shots will provide against illness. But Dr. Paul Offit, a committee member, said it’s unclear whether the immune response data will translate into significant protection. “I just think we need a higher standard for protection and than what we’re being given — I think it’s uncomfortably scant,” said Offit, an infectious disease expert at Children’s Hospital Philadelphia, about the data presented at the meeting. The FDA panel members seemed to agree that it would be better to target omicron BA.4 or BA.5. But this could create logistical challenges for the vaccine companies because they have been focused on BA.1. The manufacturing process for a different subvariant would take about three months. Panel member Dr. Mark Sawyer said the FDA risked falling even further behind the evolution of the virus if it did not act soon. “Given that state of evolution, we are going to be behind the eight ball if we wait longer,” said Sawyer, a professor of pediatrics University of California San Diego. Novavax presented data showing a booster dose of its current vaccine, which targets the original virus strain, produced a strong immune response against the omicron subvariants. Dr. James Hildreth, a temporary committee member, said he was most impressed by Novavax’s data and encouraged the FDA to quickly authorize the shot for use in the U.S. However, FDA official Jerry Weir said the Novavax data hasn’t been independently verified by the agency. Panel member Dr. Cody Meissner said he was worried there isn’t enough safety data on how changing the vaccines’ composition might impact heart inflammation, or myocarditis, as a side effect. Pfizer and Moderna’s current shots have been associated with an elevated risk of myocarditis in adolescent boys. “We need more study or research into what is the association with vaccines and myocarditis,” Meissner said. Marks said it’s crucial to make a decision soon on whether to update the vaccines, so the manufacturers have time to produce the shots in time for the fall. However, Congress has not appropriated money for the U.S. to buy additional vaccines. The White House has warned that without more funding, the U.S. might have to ration shots in the fall for people at highest risk such as the elderly. Dr. Ashish Jha, who coordinates the U.S. Covid response, has said other countries have already entered negotiations with the vaccine makers for updated shots. The White House has carved out $5 billion in funding to get talks with companies started as the administration waits on more money from Congress. The $5 billion the White House is using for vaccines was originally intended for Covid tests and protective equipment, which means there is now less money for those other crucial tools to fight the pandemic. See also FDA Press Release (June 30, 2022): https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-recommends-inclusion-omicron-ba45-component-covid-19-vaccine-booster
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Juan Lama
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The U.S. Food and Drug Administration is using a controversial strategy to evaluate the next generation of COVID-19 boosters. The approach is stirring debate as the agency works to make new, hopefully improved, boosters available in September to help prevent severe disease and save lives in the fall and winter. For the first time, the FDA is planning to base its decision about whether to authorize new boosters on studies involving mice instead of humans. "For the FDA to rely on mouse data is just bizarre, in my opinion," says John Moore, an immunologist at Weill Cornell Medicine in New York. "Mouse data are not going to be predictive in any way of what you would see in humans." But others defend the approach, arguing that the country has had enough experience with the vaccines at this point to be confident the shots are safe and that there's not enough time to wait for data from human studies. "We have 500 people a day dying of coronavirus right now. Those numbers sadly might very well rise in the fall and the winter. The question is: 'Can we do something better?'" says Dr. Ofer Levy, a pediatrics and infectious disease researcher at Harvard Medical School who also advises the FDA. "And I think the answer is: 'We can, by implementing this approach.'" The U.K. just approved a new booster The United Kingdom just approved a new booster that targets both the original strain of the virus and the original omicron variant, called BA.1 — a so-called bivalent vaccine. But the FDA rejected BA.1 bivalent boosters last spring. Instead, the FDA told the vaccine companies that make the mRNA vaccines, Moderna and Pfizer and BioNTech, to develop bivalent vaccines that target the dominant omicron subvariants — BA.4 and BA.5 — in the hopes they will offer stronger, longer-lasting protection. That's why the FDA decided to use a new, streamlined strategy for testing the new boosters. The agency is asking the companies to initially submit only the results of tests on mice. Regulators will rely on those results, along with the human neutralizing antibody data from the BA.1 bivalent booster studies, to decide whether to authorize the boosters. The companies will continue to gather more data from human studies; those results probably won't be available until late October or early November. But the big concern is the boosters may not work as well as the mouse data might suggest. Mouse experiments are notoriously unreliable. And with the government telling people not to get the old boosters now and rejecting the first bivalent vaccines, the FDA really needs good evidence that the BA.4/5 boosters are in fact better, critics say. "We need to make sure that we have solid immunogenicity data in people to show that you have a dramatically greater neutralizing antibody response against BA.4, BA.5," says Dr. Paul Offit of the University of Pennsylvania, who also advises the FDA. "I think anything short of that is not acceptable." Some also worry that the approach may further erode the long-faltering efforts to persuade people to get boosted. "I think it would be good to have neutralizing antibody data in a small group of humans," says Dr. Monica Gandhi, an infectious disease researcher at the University of California, San Francisco. "Otherwise, extrapolation may be considered too great." But others agree the time constraints mean the country can't wait for more evidence. The billions of people who have gotten Moderna and Pfizer-BioNTech mRNA vaccines show how safe they are, those experts say. The new booster will be identical to the original vaccines except it will contain genetic coding for two versions of the protein the virus uses to infect cells — the protein from the original vaccine and proteins from the BA.4 and BA.5 omicron subvariants. And some scientists say health officials know enough about how vaccines work to start handling the COVID-19 vaccines like the flu vaccines, which are changed every year to try to match whatever strains are likely to be circulating but aren't routinely tested again every year. "We're going to use all of these data that we've learned through not only from this vaccine but decades of viral immunology to say: 'The way to be nimble is that we're going to do those animal studies," says Deepta Bhattacharya, an immunobiologist at the University of Arizona College of Medicine in Tucson. "We're really not going out too far on a limb here." The companies are expected to submit their data to the FDA by the end of the month and the administration hopes to make millions of doses of the new boosters available starting in September.
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The FDA halted the use of two monoclonal antibody treatments for COVID-19 because they are not effective against the omicron variant of SARS-CoV-2, which now accounts for almost all U.S. cases. The FDA revised the emergency use authorizations for the two treatments bamlanivimab and etesevimab administered together, and the cocktail of casirivimab and imdevimab. Their use will now be limited to infections that are likely to have been caused by a variant that is susceptible to the treatments. “Because data show these treatments are highly unlikely to be active against the omicron variant, which is circulating at a very high frequency throughout the United States, these treatments are not authorized for use in any U.S. states, territories, and jurisdictions at this time,” Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research, said in a press release. Cavazzoni said this will avoid exposing patients to side effects from treatments “that are not expected to provide benefit to patients who have been infected with or exposed to the omicron variant.” She said the treatments may be reauthorized in regions where patients are likely to be infected or exposed to a susceptible variant, or if they are proven affective against future variants. The FDA noted that there are several other therapies that are expected to work against omicron, including Paxlovid, sotrovimab, remdesivir and molnupiravir.
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