Diving overview:
Vaccine maker GSK on Tuesday released new data showing its respiratory syncytial virus vaccine Arexvy protected older adults over three seasons against illness caused by the infection. Over the entire period, a single dose of Alexby was 63% effective against a wide range of RSV and 67% effective against severe disease, GSK said. However, the shot’s effectiveness waned, dropping to an estimated 48% in the third season alone. Currently, the Centers for Disease Control and Prevention does not recommend a second dose of the RSV vaccine. GSK said the data from three seasons was evidence of “significant health effects” from the vaccine, but added: “Re-vaccination may be required over time to maintain optimal levels of protection.” It is expected that this will happen.”
Dive Insight:
RSV, a common respiratory infection, typically peaks in the winter and hospitalizations approximately 100,000 to 160,000 older adults in the United States each year.
Alexby became the first candidate to receive U.S. approval last year. Since then, Pfizer’s Abrysvo and, more recently, Moderna’s mResvia have joined the market.
Despite the competition, GSK has so far commanded a dominant share of the market. Evidence the company disclosed Tuesday could further strengthen the shot’s advantage.
The results come from a large Phase 3 study supporting Arexvy’s approval. Approximately 25,000 people from 17 countries participated in the study, which compared Arexvy with a placebo at several points in time.
Researchers calculated that Alexbee’s effectiveness against lower respiratory tract disease caused by RSV was 83% in the first season. This number dropped to 56% in the second season, but reached 48% in the third season. GSK said the safety data were consistent with previous results.
The findings will be presented at the CHEST 2024 Annual Meeting and shared with peer-reviewed scientific publications and regulatory authorities. Tony Wood, GSK’s chief scientific officer, said in a statement that Alexby is “the only RSV vaccine with efficacy and safety data available over three full seasons.”
“We will continue to provide data on long-term follow-up to assist recommending agencies in determining future revaccination schedules,” Wood said.
During summer meetings, CDC advisers tweaked vaccination guidance for older adults, placing more emphasis on people 75 and older and those at high risk for severe disease. Another meeting is scheduled for later this month, where advisers will further discuss the recommendations.
In a note to clients, Jefferies analyst Peter Welford speculated that Jefferies advisers may have access to GSK’s results. He wrote that while it was “difficult to draw any conclusions,” “Aleksby’s chances should be considered very unlikely at this point, but a two-year vaccination schedule is possible.”
Investors have been closely monitoring the CDC’s recommendations because any changes to vaccination schedules could affect inoculations. Developers of the RSV shot remain optimistic, but sales are down from last year because people who have received it are not encouraged to get another shot.
