Why it matters: Older adults are at higher risk.
Each year, about 60,000 adults ages 65 and older are hospitalized with RSV, and about 6,000 to 10,000 die from the virus, the FDA estimated. The Centers for Disease Control and Prevention estimates that more than 21,000 people in that age group would need to take the GSK vaccine in one year to avoid one RSV death; the number was nearly 25,000 before Pfizer’s shot.
The virus was a key driver behind the winter’s “triple epidemic” of Covid, flu and RSV, which was particularly hard on young children, resulting in overcrowded hospitals.
Babies and toddlers are also at increased risk; RSV is considered a leading killer of infants worldwide. Several treatments, including a maternal vaccine and an infant monoclonal antibody against RSV, are under review by the agency.
Background: Advisors expressed safety concerns.
At a March 1 advisory meeting on both vaccines, doctors reviewed detailed data from the drug manufacturers.
Pfizer’s product, called Abrysvo, was found to be nearly 67 percent effective against cases of the virus with two symptoms and 86 percent effective against cases with three or more symptoms, according to data submitted to the FDA. The GSK vaccine, called Arexvy, is said to be nearly 83 percent effective against RSV
But the advisory panel also expressed concern about some cases where vaccine recipients developed autoimmune syndromes shortly after receiving the injections.
In a Pfizer study of about 34,000 patients who received the RSV vaccine, one week after the injection, one patient developed a life-threatening case of Guillain-Barré syndrome, a condition in which the immune system attacks the nervous system. A second patient developed a subtype of that condition, called Miller Fisher syndrome, eight days after receiving the injection.
Those cases put the incidence of the condition at about one in 9,000, although they are typically seen at a rate of about one in 100,000 in the general population. Some consultants, also noting the low incidence of severe RSV in the patient pool, found those numbers alarming. The FDA advisory panel’s final vote in favor of the safety and efficacy of the Pfizer vaccine was 7 to 4. The panel voted 10 to 2 for the GSK vaccine, which was also related to one Guillain-Barré case and two others from a possibly related disorder.
Now what: when will the recordings be available?
CDC advisers are expected to discuss recommendations to healthcare providers about the injections at a meeting next month. So far, they have indicated that the data from the GSK and Pfizer studies support the use of the vaccines in people age 65 and older.
A spokeswoman for Pfizer, Jerica Pitts, said the company was ready to ship the vaccine. She did not know the price of the vaccine, but said there would be no co-payment for vaccines deemed medically necessary under Medicaid and Medicare. GSK previously said its vaccine would be available in the fall.
