A examine of the single-dose respiratory syncytial virus (RSV) vaccine in older adults exhibits that vaccine efficacy waned throughout three RSV seasons however suggests a booster vaccination dose 1 yr after preliminary vaccination did little to supply further efficacy.
The examine, a part 3 medical trial on GSK’s Arexvy (adjuvanted RSV prefusion F protein-based vaccine [RSVPreF3 OA]), was revealed final week in The Lancet Respiratory Drugs.
Although a number of medical trials regarding RSV vaccines in older adults and pregnant ladies have been revealed because the vaccines first grew to become out there in 2023, this is likely one of the first monitoring efficacy over subsequent RSV seasons.
Members within the examine have been enrolled between Could 25, 2021, and January 31, 2022, and the trial ended on Could 31, 2024. The uncovered inhabitants included 24,972 contributors: 12,469 obtained RSVPreF3 OA, and 12,503 obtained a placebo earlier than the primary RSV season.
Efficacy of 62% in stopping RSV
Of the vaccine recipients, 4,988 obtained a placebo dose (RSV single-dose group) and 4,968 a second RSVPreF3 OA dose (RSV revaccination group) earlier than RSV season two. The typical age of the contributors was 69.5 years, and 44% have been 70 years or older.
The cumulative efficacy of a single RSVPreF3 OA dose in stopping RSV-related decrease respiratory tract illness over three RSV seasons was 62.9% (97.5% confidence interval [CI]46.7% to 74.8%). Efficacy over three seasons was 51.1% (95% CI, 40.3% to 60.2%) in opposition to RSV-related acute respiratory sickness.
Total, efficacy in opposition to RSV infections was highest throughout season one and in opposition to RSV A infections (69.8%) in comparison with RSV B infections (58.6%).
“A lower was noticed from season one to season three, with a lesser decline between seasons two and three than between seasons one and two,” the authors, a few of whom are GSK scientists, wrote. In season one, efficacy was 82.6%, then dropped to 56.1% in season two and 48.0% in season three.
In season three, the efficacy of the booster-dose group was 68.4% (95% CI, 24.6% to 89.1%).
Efficacy estimates for the revaccination routine have been typically in the identical vary as these noticed for a single dose.
“Efficacy estimates for the revaccination routine have been typically in the identical vary as these noticed for a single dose, though level estimates for the revaccination routine have been larger for a number of endpoints,” the authors stated.
Questions direct future examine
In a commentary on the examine, Farina Shaaban, MD, and Louis Bont, MD, of the College Medical Middle Utrecht within the Netherlands, stated the examine illustrates the considerations round reaching long-term RSV safety for older adults. They counsel 5 areas of examine wanted to grasp lasting immunity in opposition to RSV, together with a data hole between RSV immunization and immune-mediated neuropathies (together with Guillain-Barre syndrome).
Additionally they wrote that nations have conflicting pointers in regards to the usefulness of booster doses in pregnant ladies, which echoes the considerations seen with booster doses and older adults on this examine.
“Efforts are wanted to higher perceive the gaps in data that these questions spotlight,” they wrote. Regardless of these gaps, they argued it was time for the worldwide introduction of RSV immunization.
