The first vaccine for respiratory syncytial virus, often just called RSV, is a step closer to achieving approval from the U.S. Food and Drug Administration.
A 12-member Vaccines and Related Biological Products Advisory Committee on Tuesday voted that the Pfizer RSV vaccine, designed for adults 60 and older, meets safety and efficacy standards. That recommendation makes it likely the vaccine will receive FDA approval in May, after which the Centers for Disease Control and Prevention will consider making the shots available to the public.
The panel is considering a different vaccine for RSV Wednesday, as well, this one by GlaxoSmithKline.
RSV is a highly contagious respiratory illness that is often confused with influenza because of some similarity in symptoms. It strikes people of all ages, but is typically most severe in young children and older adults. Most cases are mild, but RSV can lead to inflammation of the airways and sometimes pneumonia. And it can be miserable.
The CDC has said that as many as 177,000 hospitalizations and 14,000 deaths occur from the illness every year among older patients, 65 and up. More than 2.2 million cases with symptoms occur yearly. The public health agency said that RSV frequently leads to pneumonia in hospitalized adults.
The FDA said the Pfizer vaccine was 66.7% effective at preventing lower respiratory tract illness with two or more symptoms and even more effective — 85.7% — at preventing illness with three or more symptoms.
But some panelists said the vaccine was effective, but not necessarily safe. Per CNN, “Although a majority of the committee voted in favor of the vaccine, some members expressed concerns about the vaccine’s ‘important potential risk: of Guillain-Barre syndrome.’ Two adults among the 20,000 vaccine recipients in Pfizer’s Phase 3 clinical trial developed symptoms consistent with the rare neurological disorder within nine days of receiving the shot.”
NBC News quoted Dr. Hana El Sahly, the FDA advisory committee chair: “It was a 1 in 9,000 risk of (Guillain-Barre syndrome), which is concerning.” He voted that the drug was effective, but questioned its safety.
The FDA briefing paper said the most common side effects were fatigue, headache, muscle pain and pain at the injection site. NBC said the side effects for the GlaxoSmithKline vaccine are similar, “but participants in that trial reported side effects more frequently than those in Pfizer’s did.”
NBC also noted that 11 RSV vaccines are in U.S. trials at the moment. Moderna has indicated its version could be submitted to the FDA for a recommendation by July.
The company told CNBC that its vaccine is 84% effective at preventing older adults from getting RSV.
Pfizer agreed to the FDA’s recommendation to conduct a safety study after potential approval.