Blood sample for respiratory syncytial virus (RSV) test
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The Food and Drug Administration’s independent advisors on Tuesday really helpful what can be the world’s first RSV vaccine, a shot from Pfizer for adults ages 60 and older, despite safety concerns after two trial participants developed a rare neurological disorder.Â
A majority of the FDA committee members backed the vaccine, but they wrestled with separate votes on whether the security and efficacy data are adequate to support an approval by the agency. The FDA is predicted to make its decision in May.
There currently is not any vaccine to guard older adults from respiratory syncytial virus, which kills 1000’s of seniors every 12 months. Pfizer’s shot could grow to be the primary to receive FDA approval.
In the primary vote Tuesday, seven FDA committee members said the security data was adequate for an approval, while 4 said it was not, and one member abstained.
The vote followed concerns on the FDA and amongst advisory committee members about two cases of Guillain-Barre syndrome amongst about 20,000 vaccine recipients. Guillain-Barre is a rare neurological disorder during which the body’s immune system mistakenly attacks the nerves.
Symptoms can range from temporary weakness to paralysis. Most patients, even those with severe cases, get better.
Within the second vote, seven committee members said the vaccine effectiveness data was adequate, while 4 said it was not, and one member abstained.
The shot was about 86% protective against lower respiratory tract illness with three or more symptoms, and 66.7% effective against the identical condition with two or more symptoms, based on an FDA review of Pfizer’s data. The symptoms included wheezing, shortness of breath, rapid and shallow respiratory in addition to mucus production.
In adults ages 65 and older, RSV causes 6,000 to 10,000 deaths and 60,000 to 160,000 hospitalizations per 12 months, according the Centers for Disease Control prevention. The danger of hospitalization increases with age, and adults ages 70 and older are more vulnerable.
Amongst adults of all ages hospitalized with RSV, 19% require intensive care and 4% die, based on CDC data from three seasons. Mortality is the best amongst seniors.
Pfizer’s vaccine comprises each strains of RSV, which flow into at the identical time during fall and winter. The shot is run as a single 120 microgram dose.
The Guillain-Barre cases
The FDA considers the 2 Guillain-Barre cases in the course of the trial as possibly linked to the vaccine, said Dr. Nadine Peart Akindele, an agency official. The FDA has asked Pfizer to develop a security study that can monitor Guillain-Barre risks after an approval, which the corporate has agreed to do.
A 66-year-old man within the U.S. developed Guillain-Barre, and a lady of the identical 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 girl has since recovered, and the person’s symptoms were resolving as of the last update, based on FDA.
But Alejandra Gurtman, a Pfizer executive, maintained that the corporate didn’t discover any safety concerns in the course of the trial and that the vaccine was well tolerated.
Gurtman pointed to other potential causes of the Guillain-Barre cases, noting that the person had suffered a heart attack and the girl had an upper respiratory tract infection. But Dr. Marie Griffin, an FDA advisory committee member, said the cases raise serious safety concerns.
“It seems to me that one case is a red flag. Two cases could be very concerning and it’s concerning to me that Pfizer doesn’t think that there are any safety concerns,” said Griffin, a professor of health policy at Vanderbilt University Medical Center
FDA says safety monitoring critical
Dr. Hana El Sahly, who chairs the FDA advisory committee, also said the Guillain-Barre cases raise a major safety concern. El Sahly said the disease has an incidence of about one in 100,000 amongst people ages 60 and older, but within the trial the speed looks more like one in 9,000.
“So that is major if we take it at this level,” El Sahly said, while noting that there is significant uncertainty about what the actual rate of the disease can be amongst vaccine recipients. “But nonetheless, it’s significant when it comes to incidence,” she said.
Dr. David Kaslow, a senior official within the FDA’s vaccine division, said safety monitoring shall be “critically necessary” if Pfizer’s RSV vaccine is approved.
The FDA is currently reviewing Pfizer’s proposal to check the chance of Guillain-Barre syndrome amongst Medicare beneficiaries. The FDA has the authority to require such a study after approval if the agency determines that’s needed.
Incomplete efficacy data
On the time of Tuesday’s meeting, there was not enough data to judge the effectiveness of Pfizer’s vaccine against severe disease requiring hospitalization, oxygen support or a mechanical ventilator, based on the FDA. Data was also not available on how long protection from the vaccine will last, based on the agency.
Pfizer also didn’t have data on how effective the vaccine is for elderly individuals with weak immune systems or for those in frail health, based on the FDA.
Griffin, the physician at Vanderbilt University Medical Center, said she was concerned that the vaccine was tested in a comparatively healthy population during which hospitalizations were low, and there wasn’t any data on nursing home residents and folks in frail health.
Akindele, the FDA official, said real-world evidence after a vaccine rollout could answer how much protection it provides for those in fragile health. The information would then be used to find out whether the FDA must make any adjustments to how the shot is used, she said.
Pfizer is conducting its clinical trial over two RSV seasons with greater than 34,000 people enrolled. The available efficacy and safety data is from the primary season.
When asked what would occur if data from the second season isn’t as strong after an approval, Akindele said the FDA would reevaluate the shot and meet with the committee again to find out how one can proceed.
Pfizer estimates that if 50% of individuals ages 60 and older receive the shot, the vaccine could prevent greater than 5,000 deaths, 68,000 hospitalizations, 51,000 emergency department visits and greater than 422,000 outpatient visits.
