The U.S. Food and Drug Administration (FDA) has announced the withdrawal of the emergency use authorizations (EUAs) for the original Moderna and Pfizer-BioNTech COVID-19 mRNA vaccines. This decision streamlines the immunization process, focusing on the use of bivalent vaccines that target both the original strain and the Omicron BA.4/BA.5 subvariants. The updated bivalent vaccines are now authorized for all doses administered to individuals six months of age and older, including additional doses for high-risk groups.
Streamlining Vaccination Strategy
The FDA's decision reflects an effort to simplify messaging and increase vaccine uptake. According to Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, this approach aims to encourage future vaccination. The previous strategy involved initial doses of the original vaccines followed by a bivalent booster, but the updated guidance recommends that individuals receive the bivalent vaccine for all doses.
Bivalent Vaccine Authorization
The bivalent vaccines have been authorized for all doses, including for those not previously vaccinated. This includes a second bivalent booster shot for seniors over 65 years old, addressing concerns about waning immunity in this population. Dr. Matthew Laurens from the University of Maryland School of Medicine emphasized the importance of utilizing available vaccines to protect against severe consequences, particularly for high-risk individuals.
Addressing Variant Evolution
The original COVID-19 vaccines were designed to target the initial strain of the virus first identified in Wuhan, China. However, the Omicron variant and its subvariants have become the dominant strains globally. The FDA's shift to bivalent vaccines reflects the evolution of the virus and the need for updated protection. The FDA will explore modifying the vaccine formulation for the fall of 2023, with advisors meeting in June to discuss potential changes.
Novavax Vaccine Availability
While the FDA authorization modifications primarily affect the mRNA vaccines from Pfizer and Moderna, the protein-based COVID-19 vaccine developed by Novavax remains available in the United States. Adults who have already received two doses of the Novavax vaccine are eligible for a third dose, provided they are at least 18 years or older.
Future Considerations
Experts continue to study COVID-19 to better understand its seasonal patterns and viral development. According to Dr. John Brownstein, an epidemiologist and chief innovation officer at Boston Children’s Hospital, the revised COVID-19 immunization strategy may require further adjustments as the virus evolves. The FDA has stated that available data indicate that almost all of the U.S. population aged five years and older now have antibodies against SARS-CoV-2, either through vaccination or infection.
