CDC Advisers Recommend Use of GSK, Pfizer RSV Vaccines for Adults Aged 65 and Over

A person poses with a syringe in front of the Pfizer Inc. logo on Dec. 11, 2021. Dado Ruvic/Reuters

An advisory committee to the Centers for Disease Control and Prevention (CDC) on June 21 voted to recommend that adults aged 65 and over receive one of the newly approved vaccines for respiratory syncytial virus (RSV).

The CDC’s Advisory Committee on Immunization Practices voted 9–5 in favor of recommending two different RSV vaccines—GlaxoSmithKline (GSK) and Pfizer’s RSV shots—taken in a single dose, for people aged 65 and older following “shared decision-making” between doctors and patients.

While some panelists wanted broader recommendations, others raised concerns that there was not enough data showing how effective the shots are in individuals over the age of 75 and other high-risk groups.

“Those who are at high risk for disease and [are at] high risk for hospitalizations and death were actually not included in the trials,” said committee member Dr. Helen Keipp Talbot. “The patient population that participated in the study were younger and healthier and had fewer comorbid conditions, were not immunocompromised and were not living in nursing homes.”

The committee also voted 13–0 in favor of permitting individual adults between the ages of 60 and 64 to receive a single-dose RSV vaccine following “clinical decision-making,” between doctors and patients. One panel member abstained from that vote.

Outgoing CDC Director Rochelle Walensky will decide whether to accept the panel’s recommendations in the coming days.

RSV is a common respiratory virus that typically causes mild illness and symptoms such as a runny nose, decreased appetite, coughing, wheezing, and fever in most healthy adults. Generally, individuals recover within a couple of weeks, according to the CDC.

A human respiratory syncytial virus, also known as RSV, shown in a 1981 electron microscope image. Centers for Disease Control and Prevention via AP

Clinical Data Results

However, in serious cases—typically among older adults and infants younger than six months of age or those with weakened immune systems—it can develop into a severe infection such as bronchiolitis (inflammation of the small airways in the lung) and pneumonia, requiring hospitalization.

The CDC estimates that 60,000 to 160,000 adults aged 65 years and older are hospitalized for RSV infections each year, with the virus leading to the deaths of 6,000 to 10,000 annually among that age group.

Both Pfizer’s vaccine, known as Abrysvo, and GlaxoSmithKline’s vaccine, called Arexvy, were approved by the Food and Drug Administration (FDA) in May for use in individuals 60 years and older to prevent RSV infections.

The FDA’s approval of GlaxoSmithKline’s vaccine was based on its analysis of data from an ongoing, randomized, placebo-controlled clinical study conducted in the United States and internationally in individuals aged and older.

In that study, approximately 12,500 participants received Arexvy and 12,500 participants received a placebo. The results showed that among those who received Arexvy and those who received a placebo, the shot “significantly reduced the risk of developing RSV-associated LRTD by 82.6 percent and reduced the risk of developing severe RSV-associated LRTD by 94.1 percent,” according to the FDA.

However, more recent results published by GlaxoSmithKline on Wednesday showed that its efficiency fell to 77.3 through the middle of the second RSV season, and 67.2 percent over two seasons.

Against severe disease, efficacy was 94.1 percent during the first season, 84.6 percent at mid-season, and 78.8 percent over two seasons, according to the results.

Vaccine Pricing

Pfizer’s approval was based on data from its pivotal Phase 3 clinical trial, a global, randomized, double-blind, placebo-controlled study comprised of approximately 37,000 participants.

That study found that the vaccine prevented RSV-associated lower respiratory tract illness and RSV-associated acute respiratory illness in individuals aged 60 and over “without evident safety concerns.”

Specifically, the study found that it reduced the risk of symptomatic illness by as much as 86 percent.

However, data presented by Pfizer to the CDC did show that protection waned slightly at around 18 months following vaccination, though it was still as high as 78 percent, according to a study published by the New England Journal of Medicine.

During the meeting, Pfizer said it expects to price the vaccine to be around $180 to $270 per dose, although this could change, citing competitive price negotiations on the shots.

GSK, meanwhile, said it expects to price its shot between $200 and $295 per dose. Both companies have said they expect the RSV vaccines to eventually become multibillion-dollar sellers.

Signage for GlaxoSmithKline on its offices in London, Britain, March 30, 2016. Reuters/Toby Melville/File Photo

Side Effects

Both of the vaccines come with side effects including pain at the injection site, fatigue, headache, and muscle pain. In participants who were injected with GSK’s vaccine, atrial fibrillation (abnormal heartbeat) within 30 days of vaccination was reported in 10 participants who received Arexvy and 4 participants who received the placebo.

Still, GSK’s senior vice president and global head of vaccines research and development, said last month that the company aims to make its RSV vaccine available in the fall ahead of the next RSV season.

Earlier this month, a panel of outside advisers to the FDA voted unanimously to approve a preventative antibody treatment called Nirsevimab for RSV in newborns and infants.

Currently, the only approved preventative treatment in the United States against RSV for infants is palivizumab, which is sold under the brand name Synagis, although it is generally targeted towards pre-term infants or high-risk infants and children and provides short-term protection whereas Nirsevimab is a long-acting treatment.

On Thursday, the Advisory Committee on Immunization Practices will look at whether or not to recommend giving pregnant women an RSV vaccine.

Advisers to the FDA voiced support in May for Pfizer’s maternal RSV shot to help prevent RSV in infants, despite concerns over premature births; with trial data showing there were more premature deliveries in vaccinated patients than those who received a placebo.

The FDA declined to comment on the premature births during the meeting on the vaccine but staff members did acknowledge that there was “potential uncertainty” regarding premature births.

Mimi Nguyen Ly and Reuters contributed to this report.