HealthDay News — The respiratory syncytial virus prefusion F protein-based (RSVpreF) vaccine appears to be safe and effective for preventing RSV-associated lower respiratory tract illness in older adults, according to a study published online April 5 in the New England Journal of Medicine.
Edward E. Walsh, MD, from the University of Rochester in New York, and colleagues conducted a phase 3 trial in which older adults (60 years and older) were randomly assigned to receive a single intramuscular injection of RSVpreF vaccine (17,215 participants) at a dose of 120μg (60μg each of RSV A and RSV B antigens) or placebo (17,069 participants).
The researchers found that RSV-associated lower respiratory tract illness with at least 2 signs or symptoms occurred in 11 participants in the vaccine group (1.19 cases per 1,000 person-years) and 33 participants in the placebo group (3.58 cases per 1000 person-years), resulting in a vaccine efficacy of 66.7%. Cases with at least 3 signs of symptoms occurred in 2 participants receiving the vaccine and 14 receiving placebo (0.22 vs 1.52 cases per 1000 person-years; vaccine efficacy, 85.7%). Twenty-two participants in the vaccine group (2.38 cases per 1000 person-years) and 58 participants in the placebo group (6.30 cases per 1000 person-years) had RSV-associated acute respiratory illness (vaccine efficacy, 62.1%). The incidence of local reactions was higher with vaccine than with placebo (12 vs 7%), while the incidences of systemic events were similar (27 and 26%, respectively). Similar rates of injection-related adverse events through one month were reported (1.4 and 1.0%, respectively).
“RSVpreF vaccine prevented RSV-associated lower respiratory tract illness and RSV-associated acute respiratory illness in adults (≥60 years of age), without evident safety concerns,” the authors write.
Several authors disclosed financial ties to Pfizer, which developed the RSVpreF vaccine and funded the study.
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