The U.S. Food and Drug Administration has revised its emergency use authorizations for Pfizer and Moderna's bivalent vaccines, now permitting additional doses for individuals aged 65 and older and those with certain immune deficiencies. These vaccines target both the original Covid-19 strain and the Omicron variant. Since September, they have been available under strict emergency use guidelines.
The recent amendment allows these specific groups to receive another dose before the broader fall vaccination efforts. Those 65 and older who have already received one bivalent dose can get another after four months. People with compromised immune systems can receive a second dose at least two months after their first, with further doses at their healthcare provider's discretion.
Dr. Peter Hotez, from Texas Children’s Hospital, supports the FDA's decision but questions the age threshold, suggesting it could be lowered to 60 or 50. He emphasizes the importance of making second bivalent boosters accessible and anticipates guidance on annual fall boosters by summer.
For immunocompromised children aged 6 months to 4 years, eligibility for additional doses depends on their initial vaccine. The FDA also announced that most unvaccinated individuals can now receive a single bivalent vaccine dose instead of multiple doses of the original vaccine, acknowledging that many Americans possess some immunity from prior infections or vaccinations.
Dr. Peter Marks from the FDA highlighted that most Americans over five have developed antibodies against Covid-19, either through vaccination or infection, which supports the protective benefits of bivalent vaccines. He encouraged staying updated with vaccinations to prevent severe outcomes like hospitalization and death.
Children aged 6 months to 5 years who haven't been vaccinated can now start with a two-dose Moderna series or a three-dose Pfizer-BioNTech series, depending on their age. Those who began with monovalent vaccines can receive a bivalent dose, with eligibility based on previous doses and vaccine type.
The FDA clarified that most individuals who have received one bivalent dose are not yet eligible for a second. They urged those who haven't received their first bivalent dose to do so, as only about 17% of eligible Americans have taken it.
As the effectiveness of bivalent vaccines wanes, particularly against severe outcomes, there has been demand from older adults and those with health issues for additional doses. The CDC has been limited by the EUA terms but now has more flexibility to recommend extra doses, with the Advisory Committee on Immunization Practices expected to support the FDA's changes.
For those not included in the current update, the FDA plans to decide on future vaccinations after consulting its advisory committee in June. Meanwhile, countries like Canada and the UK have already offered additional bivalent boosters to high-risk groups this spring.