FDA Is Looking for Omicron Variant-Specific Booster Vaccines in the Fall
COVID-19 booster shots administered in pharmacies next fall are likely to be somewhat different than in the past. Find out why an FDA advisory committee is calling for vaccines that are modified to be more protective against current circulating variants and how the key mRNA vaccine manufacturers have responded.
WASHINGTON, DC – The Food and Drug Administration has informed COVID-19 vaccine manufacturers seeking to update their products that they should modify them to perform better against current circulating variants.
The FDA’s Vaccines and Related Biological Products Advisory Committee recently met to discuss whether an alteration to the current vaccine strain composition of COVID-19 vaccines for booster doses is essential for the 2022 fall and winter seasons.
“As we move into the fall and winter, it is critical that we have safe and effective vaccine boosters that can provide protection against circulating and emerging variants to prevent the most severe consequences of COVID-19,” explained Peter Marks, MD, PhD, director of the Center for Biologics Evaluation and Research (CBER). “Following a thorough discussion on June 28, 2022, an overwhelming majority of the advisory committee voted in favor of including a SARS-CoV-2 omicron component in COVID-19 vaccines that would be used for boosters in the U.S. beginning in fall 2022.”
Specifically, the advice is to develop modified vaccines that add an omicron BA.4/5 spike protein component to the current vaccine composition to create a two-component (bivalent) booster vaccine.
“The COVID-19 vaccines that the FDA has approved and authorized for emergency use have made a tremendous difference to public health and have saved countless lives in the U.S. and globally,” Marks points out. “However, SARS-CoV-2, the virus that causes COVID-19, has evolved significantly, with recent surges around the world associated with the rapid spread of highly transmissible variants such as omicron. “
He emphasizes that currently available vaccines are highly effective in reducing serious outcomes such as hospitalization and death caused by COVID-19, “but results from post-authorization observational studies have shown that effectiveness of primary vaccination wanes over time against certain variants, including omicron.” Initial booster doses have helped reestablish protection against severe disease and hospitalization, research suggests that effectiveness against Omicron wanes over time.
“As we expect this coming year to be a transitional period when this modified booster vaccine may be introduced, we have not advised manufacturers to change the vaccine for primary vaccination, since a primary series with the FDA-authorized and approved COVID-19 vaccines provides a base of protection against serious outcomes of COVID-19 caused by circulating strains of SARS-CoV-2,” Marks notes in a press release.
In early June, Moderna, Inc., announced new clinical data on its bivalent (Omicron) COVID booster candidate, mRNA-1273.214. The company reports that, one month after administration in previously vaccinated and boosted participants, “a 50 µg booster dose of mRNA-1273.214 elicited potent neutralizing antibody responses against the Omicron subvariants BA.4 and BA.5 in all participants regardless of prior infection.”
Based on that and prior data, the company says it is completing regulatory submissions in the coming weeks requesting to update the composition of the booster vaccine to mRNA-1273.214.
Pfizer Inc. and BioNTech SE also recently announced positive data evaluating the safety, tolerability, and immunogenicity of two Omicron-adapted COVID-19 vaccine candidates: one monovalent and the other bivalent, a combination of the Pfizer-BioNTech COVID-19 Vaccine and a vaccine candidate targeting the spike protein of the Omicron BA.1 variant of concern.
The companies report that data from the Phase 2/3 trial found that a booster dose of both Omicron-adapted vaccine candidates elicited a substantially higher immune response against Omicron BA.1 as compared to the companies’ current COVID-19 vaccine. The robust immune response was seen across two investigational dose levels, 30 µg and 60 µg.