FDA authorizes second round of mRNA boosters for older and immunocompromised people

Regulatory NewsRegulatory News
| 29 March 2022 | By Michael Mezher 

The US Food and Drug Administration (FDA) on Tuesday signed off on a second round of COVID-19 vaccine booster shots for immunocompromised individuals and people 50 years of age and older.
The agency said the boosters can be administered four months after receiving the first booster dose of any authorized or approved COVID-19 vaccine in both populations.
The populations covered by the latest authorizations differ from those sought by the two vaccine makers. Pfizer had initially submitted its request for individuals ages 65 and older, while Moderna sought authorization for a second booster for all adults.
In its announcement of the expanded emergency use authorizations (EAUs) for the two vaccines, FDA said, “This action will now make a second booster dose of these vaccines available to other populations at a higher risk for severe disease, hospitalization and death. Emerging evidence suggests that a second booster dose of an mRNA COVID-19 vaccine improves protection against severe COVID-19 and is not associated with new safety concerns.”
On Twitter, FDA Commissioner Robert Califf echoed that sentiment. “The most important message from the analysis of data is that the first booster is an essential way to reduce the risk of hospitalization and death,” he tweeted. Califf noted that the US is currently experiencing relatively low rates of infections but cautioned that cases are on the rise in Europe and Asia.
“If there is a significant increase in infections, the second booster dose will be beneficial,” he said.
The decision to authorize the additional booster dose was based on safety surveillance data gathered by Israel’s Ministry of Health that included about 700,000 patients who received a fourth dose of the Pfizer-BioNTech vaccine at least four months after receiving a third dose. Most of the individuals whose data was included in the analysis were aged 60 or older.
FDA also said its decision on the additional Moderna booster was “informed by experience with the Pfizer-BioNTech COVID-19 Vaccine and safety information reported from an independently conducted study in which the Moderna COVID-19 Vaccine was administered as a second booster dose to 120 participants 18 years of age and older who received a tw-dose primary series and a first booster dose of Pfizer-BioNTech COVID-19 vaccine at least 4 months prior. No new safety concerns were reported during up to three weeks of follow up after the second booster dose.”
“We know that vaccines continue to be the best way to prevent the most serious complications from COVID-19 and to save lives,” FDA’s Center for Biologics Evaluation and Research Director Peter Marks said on a call with reporters.
“The FDA believes that this option will help save lives and prevent severe outcomes among our highest risk patients, which has been a top priority since the vaccines were first introduced. The good news is that for most people who have been vaccinated and had one booster, your original booster shot is continuing to provide you with good protection from being hospitalized or dying. If you haven’t had a first booster yet, now is a good time to get one, and if you haven’t been vaccinated at all, the potential benefits are now clear enough that you hopefully will consider this option to protect yourself and your loved ones,” Marks said.
Marks added, “That third dose provides a differentiating level of immunity that does seem to provide people with some additional benefit in terms of preventing the severe outcomes of hospitalization and death – and that seems to last.” He noted that FDA will continue to look at the data on the benefit of a second booster dose for other populations and will update the public as new findings become available.
Marks also explained the agency’s decision to extend the authorization of the boosters to individuals ages 50-60.
“In the past it’s been somewhat challenging to operationalize what high risk of serious outcomes from COVID-19 would be, but we do know that those tend to be medical comorbidities and we know that people in the age range from about 50-65, about a third of them have significant medical comorbidities. So, by choosing age 50 and up, which is something we often use for other respiratory viruses, like influenza, to consider those at higher risk, we felt like we would capture the population that might most benefit from this fourth booster dose,” Marks explained.
As to why the agency didn’t wait for a booster targeting the currently circulating omicron variant, Marks said that the jury is still out on whether that’s the right approach and noted the present lack of supply of variant-specific vaccines.
“Why didn’t we wait for an omicron-specific booster? We’ll be having a general discussion of boosters in the future, but right now it probably is a few months off before one could actually have the quantities of doses of a variant-specific booster and it’s not actually clear yet what the optimal booster should be. We do know, however, that we continue to see circulating COVID-19. We do know that some other countries around the world, for instance, the United Kingdom and some countries in Asia, are having major waves that have come after the previous omicron wave. So, we’re hoping that by taking this action, we will help allow people to take steps to protect themselves, should we have another wave that comes through this country,” Marks answered.
Marks also addressed the potential for another broader booster campaign in the fall.
“It would not be surprising if there is a potential need – I don’t want to shock anyone – but there may be a need for people to get an additional booster in the fall, along with a more general booster campaign, if that takes place, because we may need to shift over to a different variant coverage. In other words, it may be that a decision is made that rather than the vaccines we currently have, which are called vaccines against the prototype virus, that we will move to a vaccine that is either against one of the variants – whether it’s omicron, beta or delta or something else, I can’t say right now – or whether it’s some mix of different ones. It’s possible that people will need to get another vaccine,” Marks said.
The CBER director also discussed the agency’s rationale for the four-month interval and its decision not to convene an advisory committee meeting to review the boosters.
The four-month interval for this latest round of boosters was chosen based on the data from the Israeli study, Marks said. He added that the risks associated with another booster in the 50 and up population is very low and that the advisory committee was not called in because, “This was a relatively straightforward decision made based on data that was analyzed,”


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