The U.S. Food and Drug Administration has revised its emergency use authorizations for the Pfizer and Moderna bivalent COVID-19 vaccines. This update allows individuals aged 65 and older, as well as certain people with weakened immune systems, to receive additional doses before the upcoming fall vaccination campaigns. These bivalent vaccines target both the original COVID-19 strain and the Omicron variant.
Since September, these vaccines have been available in the U.S. under emergency use authorizations, which limit their administration. The FDA's recent amendment permits specific groups to receive an extra dose earlier than others. Adults 65 and older who have had one bivalent dose can get another at least four months later. Those with certain immunocompromising conditions can receive a second dose at least two months after their first, with further doses as advised by their healthcare providers.
Dr. Peter Hotez from Texas Children’s Hospital has advocated for broader access to these boosters. He questions the age threshold of 65, suggesting it could be lowered to 60 or 50. He also anticipates guidance on an annual fall booster to be released in the summer.
For immunocompromised children aged 6 months to 4 years, eligibility for additional doses will depend on their previous vaccinations. A significant change is that most unvaccinated individuals can now receive a single bivalent vaccine dose instead of multiple doses of the original vaccine, reflecting the widespread immunity in the U.S. population due to past infections or vaccinations.
Dr. Peter Marks from the FDA emphasized the importance of staying current with vaccinations, noting that the vaccines continue to prevent severe outcomes like hospitalization and death. Children aged 6 months to 5 years can now start with a two-dose Moderna bivalent 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 depending on their previous doses.
The FDA highlighted that most people who have received one bivalent dose are not yet eligible for a second. They encouraged those who haven't received their first bivalent dose to do so, as only about 17% of eligible Americans have done so.
As time has passed, older adults and those with health issues have been inquiring about the need for another bivalent dose. The CDC has observed that the effectiveness of these vaccines is decreasing, even against emergency visits and hospitalizations. However, due to the EUA terms, the CDC couldn't recommend additional doses for vulnerable individuals until now.
The updated authorizations provide the CDC and its Advisory Committee on Immunization Practices more flexibility to recommend extra doses. The ACIP is expected to support the FDA's changes in an upcoming meeting. For those not included in the current update, the FDA plans to decide on future vaccinations after its advisory committee reviews the fall strain composition in June. Meanwhile, Canada and the UK have already offered another round of bivalent boosters to high-risk groups this spring.