Pfizer and partner BioNTech announced they have submitted a request to the U.S. Food and Drug Administration (FDA) to authorize a COVID-19 vaccine booster that has been updated to target the newest Omicron subvariants.
The so-called bivalent vaccine that Pfizer-BioNTech is seeking authorization for contains the mRNA encoding the spike protein of the Omicron BA.4/BA.5 variant, along with the mRNA encoding the original spike protein of the original strain of SARS-CoV-2 that first emerged in Wuhan, China, in 2019.
The updated Omicron-targeted vaccine boosters could be offered to the public within weeks if the FDA quickly grants the emergency authorization. The FDA will be relying heavily on scientific testing of prior tweaks to the vaccine—rather than a large study of the newest boosters that could take months—to decide whether to issue the emergency use authorizations. The fast-track approach is similar to how annual changes to flu vaccines are handled.
The companies stated that their EUA application comes after the FDA issued a guidance telling them to include clinical data from the companies’ Omicron BA.1-adapted vaccine, as well as pre-clinical and manufacturing data from the latest Omicron BA.4/BA.5-adapted vaccine.
Pre-clinical data showed that a dose of the updated vaccine “generated a strong neutralizing antibody response against Omicron BA.1, BA.2 and BA.4/BA.5 variants, as well as the original wild-type strain,” the companies said on Aug. 22.
Meanwhile, a clinical study investigating the safety, tolerability, and immunogenicity of the BA.4/BA.5 vaccine in people aged 12 years and older is expected to start this month, Pfizer-BioNTech stated.
Ready to Roll Out
Albert Bourla, the chairman and CEO of Pfizer, said in a statement that the company has rapidly scaled up production and is ready to immediately start distribution of the doses if it obtains regulatory clearance.The previously-authorized COVID-19 vaccines from the two companies have been linked with heart inflammation, including myocarditis and pericarditis, data from around the world have suggested.
The primary regimens of the vaccines, which are two doses administrated several weeks apart, have been insufficient to protect against infection, and have shown waning efficacy in protecting against hospitalization amid newly emerging variants.
Dr. Rachel Presti of Washington University in St. Louis, a researcher with the Moderna trial, said of the boosters that it’s clear “none of these vaccines are going to completely prevent infection,” but also noted that previous studies of variant booster candidates suggest “you still get a broader immune response giving a variant booster than giving the same booster” again.
“I think it’s going to be interesting to see what happens. How vigorously will the CDC recommend this bivalent vaccine if [hospitalization] rates continue to decline? How eager [will] people be to get yet another booster?” Dr. Cody Meissner, who advises the FDA on vaccines, said in an interview with The Epoch Times. “And there’s a little bit of vaccine fatigue in the United States, as you know, and so we'll have to wait and see how that plays out.”
It’s uncertain whether another variant will emerge to replace the latest BA.5 variant. Mutant strains of COVID-19 have emerged around late fall or early winter over the past two years, Meissner noted. “It’s really not possible to predict what this virus is going to do and I think it makes sense to be prepared with these boosters,” he said.
