Califf is Bullish on Newly Authorized Bivalent COVID-19 Boosters Ahead of Data
In the midst of a pandemic, if you wait for all the data to come in, “you’ve missed the boat,” said FDA Commissioner Robert Califf yesterday regarding the agency authorizing both Pfizer/BioNTech’s and Moderna’s bivalent COVID-19 boosters before any clinical trials on them are complete.
Califf, speaking in a podcast from the Johns Hopkins Bloomberg School of Public Health, said the new vaccines, aimed at the new the BA.4 and BA.5 strains that are expected to surge in the fall, are a combination of multiple versions of the vaccine, including the “ancestral vaccine” containing an mRNA component of the original coronavirus strain from Wuhan, China.
This is a technique that has been employed for years in developing the flu vaccine, he said.
“We now have multiple versions of the mRNA vaccine … with two different companies doing multiple studies, showing that it’s been reliable that if you induce an immune response that is antibodies to the particular or a virus that you’re trying to take care of that that translates into a clinical benefit,” Califf said, adding, “Of course, that’s always an extrapolation when you make it, but it’s what we do with the flu vaccine every year. So it’s not something new for us.”
The two vaccine boosters are now authorized for those age 12 and older.
Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research (CBER), said in a press briefing yesterday that more data will be available on the new boosters in one to two months.
And Moderna said that its phase 2/3 trial for the newly authorized booster, now underway, has all the patients the company had hoped to enroll and the initial data should be ready later in 2022.
The FDA explained that for each bivalent COVID-19 vaccine, the agency based its decision on the totality of available evidence, including extensive safety and effectiveness data for each of the monovalent mRNA COVID-19 vaccines, safety and immunogenicity data from a clinical study of a bivalent COVID-19 vaccine that contained mRNA from omicron variant BA.1 lineage and nonclinical data obtained using a bivalent COVID-19 vaccine that contained mRNA of the original strain and mRNA in common between the BA.4 and BA.5 lineages of the omicron variant.
The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) is meeting today and Friday to scrutinize the new bivalent boosters and add any recommendations.
Califf says he’s already feeling very positive.
“The consistency of the immune response that’s being elicited by this vaccine is giving us confidence,” he said. “We’re in a time now where we can adapt the vaccine to the circumstance” and take advantage of prior knowledge.
Califf added, “And then, of course, there’s postmarketing, surveillance and evaluation, which will continue.”
Meantime, the European Medicines Agency is slated to decide this week whether to clear Moderna and Pfizer-BioNTech’s vaccines targeting the older BA.1 Omicron variant and the original strain. — Suz Redfearn