FDA Proposes Shift in COVID-19 Vaccination Strategy

Officials with the FDA are hoping to simplify COVID-19 vaccinations, with a proposed shift to the current vaccine strategy. According to documents released in advance of the FDA Vaccine and Related Biological Products Advisory Committee (VRBPAC) meeting on Thursday, officials could recommend annual COVID-19 vaccines, much like flu shots.

Currently, COVID-19 vaccination involves 2 primary shots over the course of several weeks, followed at least 2 months later by a booster. The booster shots are currently a bivalent vaccine designed to protect against the Omicron variant and other variants of concern. This schedule, however, may be confusing for some patients and makes it easy for patients to miss a booster and have lapsed immunity.

“The complexities associated with the differences in composition and regimens of the currently authorized and approved COVID-19 vaccines in the United States, the still incomplete understanding of SARS-CoV-2 immunology, and the absence of an established framework to inform periodic vaccine composition updates, leave open scientific and policy questions regarding recommendations for simplifying the immunization schedule and updating the current COVID-19 vaccines for future vaccination campaigns,” the FDA said in a briefing document.

The new suggestion, however, would suggest that most people receive whatever latest version of the vaccine is available each fall, regardless of the number of previous shots and which vaccine they received when. Some populations would still need 2 initial doses, including young children and older adults, and these populations would still receive the same formulation for all 3 shots.

The manufacturing process for the vaccines would work similarly to annual flu vaccines. Each spring, manufacturers would update the annual shot with the goal of matching the vaccine to whichever variant is likely to be dominant in the coming fall and winter months, and the updated vaccines would be available by September each year.

However, if a more serious variant emerged that was better able to evade vaccine antibodies, the briefing document notes that the VRBPAC may be called to an ad-hoc strain selection meeting.

In the upcoming meeting, the VRBPAC members will also discuss strategies to align the strain composition of all COVID-19 vaccines, including mRNA and protein-based vaccines. There are currently 4 approved vaccines, 2 of which are mRNA vaccines. Only those 2 vaccines (from Moderna and Pfizer) were updated to have a bivalent composition.

Clinical efficacy data have supported these bivalent booster vaccines. The briefing document notes that studies have found a reduction in hospitalization and death among those who received the bivalent vaccines, which is most apparent in older individuals, although younger individuals also benefit. The document notes that although not exactly the same, the pattern of response is similar to that observed with an annual influenza vaccine.

Updating the vaccine composition each year could be logistically challenging, but the briefing document notes that experience from influenza strain analysis and vaccine composition could make implementation more possible.

“Additionally, based upon modeling using the available evidence, in the absence of the emergence of a variant that essentially escapes protection conveyed by the existing vaccines, the administration of an updated vaccine on an annual basis also appears to be reasonable,” the document concludes. “As such, an annual frequency may provide a reasonable and practical starting point to implement COVID-19 vaccine composition evaluation and recommendations in the US.”

REFERENCE

Vaccines and Related Biological Products Advisory Committee Meeting January 26, 2023 Meeting Briefing Document. FDA. Released January 23, 2023. Accessed January 23, 2023. https://www.fda.gov/media/164699/download