CDC advisory panel examines GSK and Pfizer RSV vaccines, set to vote today on recommended use

The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) will vote this afternoon on recommendations for the use of new respiratory syncytial virus (RSV) shots from GSK and Pfizer.

Both GSK’s Arexvy and Pfizer’s Abrysvo won approvals last month, becoming the first vaccines ever for the condition, which typically leads to cold-like symptoms but can progress to severe disease and be fatal. Specifically, the vaccines scored approvals to prevent lower respiratory tract disease caused by RSV in adults 60 and older.

On Wednesday morning, both companies presented data on the efficacy and safety of their respective vaccines in the second RSV season after administration.

The CDC also provided a cost-effectiveness model for the two shots, which showed GSK’s vaccine providing significantly more value—even when priced at $270 per dose compared to $200 for the Pfizer shot.

Both companies said on Wednesday that they have not arrived at a final price for their shots, prompting an appeal from committee member Helen Keipp Talbot, M.D., of Vanderbilt University.

“We are voting today at around 4:30. If you could please come up with a price before that it would be incredibly helpful,” Talbot said. “None of us buy a car unless we know how much it costs.”

The ACIP experts will recommend who should receive the new vaccines and how often. Both companies have said their shots will be ready to be distributed this fall.

While GSK’s vaccine has shown efficacy of 82.6% in preventing RSV in year one and 94.1% efficacy in preventing severe disease, those figures drop to 77.3% and 84.6% in the second RSV season, respectively, with a median follow-up time of 14 months from administration.

Additionally, another subset of the trial showed that those receiving a second shot a year after initial administration received no boost in second season efficacy. This means "revaccination after 12 months does not appear to confer additional benefit,” the company wrote.

Meanwhile, Pfizer’s vaccine has shown 66.7% efficacy in the first year against RSV, with 85.7% protection against severe disease. In the second season, at month 18, the efficacy numbers wane to 49% and 78.6%, respectively, the company said.

Both companies said on Wednesday that they will test a subset of trial participants with a booster dose after two years post initial administration.