In landmark decisions, vaccine advisers to the Food and Drug Administration have recommended that two experimental vaccines for respiratory syncytial virus (RSV) be approved for use in older adults.
The Vaccines and Related Biological Products Advisory Committee on Tuesday handed down a 7 to 4 vote in favor of recommending the approval of Pfizer’s new shot, with one abstention. In a separate vote Wednesday, it gave GSK’s vaccine a 10 to 2 nod for safety, and a unanimous thumbs up for efficacy.
If one or both vaccines make it to market, they will be the first shots available for use in preventing RSV-related illness in older adults. In clinical trials, Pfizer’s vaccine was found to be 66.7% effective against RSV illness with more than two symptoms, and GSK’s vaccine proved 82.6% effective in people aged 60 and older. GSK’s vaccine also includes an adjuvant to improve immune response — the same adjuvant included in its shingles vaccine Shingrix, according to CIDRAP News.
A dangerous virus for LTC
RSV can cause severe respiratory illness in older adults and children. It is estimated to infect up to 10% of nursing home residents per year, and leads to death in 2% to 5% of cases, studies have found. Long-term care facilities are vulnerable to seasonal outbreaks of the disease.
The disease is also underreported, and its impact on public health is unappreciated — even among clinicians, William Schaffner, MD, medical director of the National Foundation for Infectious Diseases (NFID) has told McKnight’s Clinical Daily. In the United States, RSV is estimated to cause 6,000 to 10,000 deaths each year in seniors, according to the Centers for Disease Control and Prevention.
With more time to see if the data holds up, the FDA is scheduled to decide whether to approve the drugs for commercial use in May. The CDC also must give the drugs its blessing.
Safety concerns
Despite the affirmative votes, many FDA advisory committee members voiced concerns about the possibility of rare adverse reactions found in trials of Pfizer’s RSV vaccine. They also lamented the dearth of clinical trial participants aged 80 and older, considering the target population for the drugs. Some called for additional study and data from Pfizer, as has the FDA.
“I think the primary endpoint was clearly met here,” said Daniel Feikin, MD, a committee member who voted yes on Pfizer’s drug, as reported by the Associated Press. “It’s disappointing we don’t have more data on the high-risk groups and severe outcomes.”
A new era for respiratory virus care
Commercial availability of RSV drugs would mark a new era for respiratory disease care, according to Inside Health Policy. All of the three top respiratory viruses could potentially have preventive therapies by the year’s end, it reported.
“RSV remains the last of the three great respiratory viruses without a vaccine,” Schaffner, who is also an infectious disease specialist at Vanderbilt University Medical Center, told the news outlet.
Scientists first attempted to make RSV vaccines in the 1960s. The new vaccines are entirely different drugs, experts noted.
The NFID has called for more diagnostic testing for RSV in the United States, along with better surveillance, diagnosis, prevention and treatment.
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