FDA committee votes on Pfizer injection for the elderly

Independent advisers to the Food and Drug Administration on Tuesday recommended Pfizer’s RSV vaccine for adults 60 and older, despite safety concerns after two people who received the vaccine developed a rare neurological disorder.

Although a majority of FDA committee members backed the vaccine, they struggled with two separate votes over whether the safety and efficacy data are adequate to support the agency’s approval.

In the first vote, seven committee members said the safety data was sufficient for approval, while four said it was not and one member abstained.

In the second vote, seven members said the efficacy data were adequate, four said they were not, and one member abstained.

The vote follows concerns from the FDA and advisory committee members about two cases of Guillain-Barré syndrome among about 20,000 vaccinees. Guillain-Barré is a rare neurological disorder in which the body’s immune system mistakenly attacks nerves.

Symptoms can range from brief weakness to paralysis. Most patients, even those with severe cases, recover.

The FDA considers the cases possibly linked to the vaccine, said Dr. Nadine Peart Akindele, an agency official. The FDA asked Pfizer to conduct a safety study on Guillain-Barré syndrome, which the company agreed to do.

Although respiratory syncytial virus causes mild illness in most people, older people are at higher risk of serious illness. There is currently no RSV vaccine approved for the elderly.

Pfizer’s vaccine contains both strains of RSV, which circulate at the same time during fall and winter. The injection is given as a single dose of 120 micrograms.

The vaccine was about 86% protective against lower respiratory tract diseases with three or more symptoms, and 66.7% effective against the same condition with two or more symptoms, according to an FDA review of Pfizer data. Symptoms included wheezing, shortness of breath, rapid and shallow breathing, and mucus production.

At the time of Tuesday’s meeting, there was not enough data to rate the effectiveness of Pfizer’s vaccine against serious illnesses requiring hospitalization, oxygen support or a mechanical ventilator, according to the FDA. Data was also not available on the duration of protection from the vaccine, according to the agency.

Pfizer also did not have data on the effectiveness of the vaccine for older adults with weakened immune systems or those in frail health, according to the FDA.

A 66-year-old man in the United States developed Guillain-Barre, and a woman of the same age in Japan was diagnosed with Miller Fisher syndrome, a variant of Guillain-Barre. They developed symptoms seven and eight days after vaccination, respectively. The woman has since recovered and the man’s symptoms had been clearing since the last update, according to the FDA.

Although the FDA considers Guillain-Barré syndrome a significant potential risk, Pfizer executive Alejandra Gurtman maintained that the company did not identify any safety issues during the trial and that the vaccine was fine. tolerated.

Gurtman pointed to other potential causes of Guillain-Barre’s cases, noting that the man suffered a heart attack and the woman had an upper respiratory infection. But Dr. Marie Griffin, a member of the FDA’s advisory committee, said the cases raised serious safety concerns.

“It seems to me that one case is a red flag. Two cases are very concerning and it worries me that Pfizer doesn’t think there are safety concerns,” said Griffin, professor of health policy at Vanderbilt. University Medical Center. .

Dr. David Kaslow, a senior official in the FDA’s vaccines division, said safety oversight would be “crucially important” if Pfizer’s RSV vaccine is approved.

The FDA is currently reviewing Pfizer’s proposal to study the risk of Guillain-Barré syndrome in Medicare beneficiaries. The FDA has the authority to require such a study after approval if the agency deems it necessary.

A 61-year-old woman also had an allergic reaction eight hours after vaccination. She had shortness of breath and chest pains, lost consciousness and was hospitalized. Her symptoms disappeared five days later. The FDA also considers this case may be related to the vaccine.

In adults ages 65 and older, RSV causes 6,000 to 10,000 deaths and 60,000 to 160,000 hospitalizations annually, according to the Centers for Disease Control Prevention. The risk of hospitalization increases with age and adults aged 70 and over are more vulnerable.

Among adults of all ages hospitalized with RSV, 19% require intensive care and 4% die, according to CDC data over three seasons. Mortality is highest among seniors.

Pfizer estimates that if 50% of people aged 60 and over receive the vaccine, the vaccine could prevent more than 5,000 deaths, 68,000 hospitalizations, 51,000 emergency room visits and more than 422,000 outpatient visits.

Griffin, the physician at Vanderbilt University Medical Center, said she was concerned the vaccine was tested in a relatively healthy population in which hospitalizations were low and there were no data on residents of the homes. retirement and people in fragile health.

Akindele, the FDA official, said concrete evidence after the rollout of a vaccine could answer the protection it offers to people with fragile health. The data would then be used to determine whether the FDA should make any adjustments to how the vaccine is used, she said.

Pfizer is conducting its clinical trial over two RSV seasons with more than 34,000 people enrolled. The efficacy and safety data available date from the first season.

When asked what would happen if the second season’s data wasn’t as strong after an approval, Akindele said the FDA would re-evaluate the shot and meet with the committee again to determine how to proceed.

This is a developing story. Please check for updates.