A healthcare employee prepares a flu vaccine before giving it to an area resident in Los Angeles, United States, December 17, 2022.
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Individuals who receive PfizerAn RSV vaccine for the elderly must be monitored for Guillain-Barre syndrome after two people developed a nervous system disorder after receiving an injection, researchers have said in clinical trial results published within the Latest England Journal of Medicine.
The researchers concluded that the vaccine is effective in stopping lower respiratory tract disease in adults aged 60 and over, with no apparent safety concerns. But they marked the Guillain-Barre cases as a possible cause for concern.
“If the RSVpreF vaccine is approved and beneficial, these antagonistic events warrant close monitoring in future trials and with real-world data and post-marketing surveillance,” the researchers wrote. The study, which was published Wednesday, was supported by Pfizer.
Guillain-Barre syndrome is a rare disorder through which the body’s immune system mistakenly attacks the nerves. Symptoms can range from transient weakness to paralysis, in keeping with the National Institutes of Health. Most individuals get well, even after severe cases.
The decision from scientists to closely monitor the possible link between the vaccine and Guillain-Barre reflects the position of the Food and Drug Administration.
The agency asked Pfizer to incorporate Guillain-Barre as an “vital potential risk” for the vaccine and to develop a security study to observe potential cases if the vaccine is approved in May. Pfizer has agreed to conduct a security study.
Independent FDA advisers endorsed the vaccine in February, although there was considerable opposition during that meeting. Seven advisers said the security data were sufficient for approval, while 4 said no and one abstained.
In an article within the Latest England Journal of Medicine, researchers said the 2 cases occurred in patients in an age group at increased risk of developing Guillain-Barre. They added that potential aspects aside from the vaccine could even have caused the event of the syndrome.
However the FDA said the agency considers the Guillain-Barre cases likely related to the vaccine since the patients developed the syndrome soon after receiving the injection, in keeping with briefing papers released in February. Pfizer concluded that the cases weren’t related, and the clinical trial data monitoring committee found no safety concerns for the vaccine.
Pfizer has the potential to grow to be the primary RSV vaccine ever approved for the elderly. RSV kills between 6,000 and 10,000 seniors annually, in keeping with the Centers for Disease Control and Prevention. It also causes 60,000 to 160,000 hospitalizations on this age group annually.
The vaccine was 86% effective in stopping lower respiratory disease with three or more symptoms and 66% effective in stopping disease with two or more symptoms, in keeping with results published within the Latest England Journal of Medicine. The injection is given as a single dose of 120 micrograms.
While the injection guarantees to scale back RSV hospitalizations and deaths amongst seniors, FDA advisers were concerned about Guillain-Barre cases at a February meeting.
Dr. Hana El Sahly, chair of the FDA committee, said the incidence of Guillain-Barre is about 1 in 100,000 amongst people aged 60 and over. But within the vaccine trial, the speed was more like 1 in 9,000.
“In order that’s vital if we take it at that level,” El Sahly said. She admitted she was still unsure in regards to the true rate of disease amongst those receiving the vaccines.
“Nevertheless, it is critical by way of prevalence,” she said of the 2 cases. Advisers who supported the vaccine also said safety monitoring could be critical after eventual FDA approval.
A 66-year-old man within the US developed Guillain-Barre syndrome, and a girl of the identical age in Japan was diagnosed with a variant of the syndrome called Miller Fisher. The patients developed symptoms seven and eight days after vaccination, respectively.
The person had a history of hypertension and suffered a heart attack shortly before he was diagnosed with Guillain-Barre, and the girl had a history of diabetes. The FDA doesn’t consider heart attack related to the vaccine.
The person’s symptoms resolved six months after onset, and the girl’s symptoms resolved completely 3 months after onset.