Positive results for the RSV vaccine in a substudy of a Phase III trial in immunocompromised patients
Every year, the infectious virus causes up to 160,000 hospitalizations and up to 13,000 deaths in the United States
Pfizer recently shared encouraging news about the safety and effectiveness of Abrysvo, their approved vaccine for respiratory syncytial virus (RSV). The results from a substudy of a Phase III clinical trial showed positive outcomes in terms of safety and the body's immune response. This is particularly important for older adults and infants who are at higher risk of severe illness from RSV. Pfizer made the announcement in a press release on Aug. 12, 2024. Immunocompromised individuals aged 18 and older, who are at risk of developing severe RSV-associated lower respiratory tract disease (LRTD), received two doses of Abrysvo.
According to Annaliesa Anderson, Pfizer's senior vice president and chief scientific officer for vaccine research and development, there is currently a lack of approved vaccines for individuals aged 18 to 59 in the United States who are immunocompromised, such as those with cancer or autoimmune disorders. This puts them at a significantly higher risk of severe complications from RSV. "The positive top-line data from this study is very encouraging and provides valuable evidence that Abrysvo could potentially help meet a significant unmet need in this vulnerable population."
According to Pfizer's press release, RSV is highly contagious and a frequent cause of respiratory illness, resulting in a significant number of hospitalizations and deaths annually in the US. It can have an effect on the lungs and respiratory system of those who are affected, posing a higher risk for certain age groups and individuals with chronic medical conditions.
In May 2023, Abrysvo received FDA approval for preventing LRTD caused by RSV in individuals aged 60 and older. In August 2023, it was also approved for infants from birth to six months through immunization of pregnant women at 32 to 36 weeks' gestational age. The European Commission followed suit with their own approvals in the same month. In September 2023, the US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommended Abrysvo as a maternal immunization. Finally, in January 2024, Health Canada approved Abrysvo for use in older adults and expectant mothers.
Previous clinical trial data comparing Abrysvo to a placebo indicated slightly higher occurrences of low birth weight (5.1–4.4%) and jaundice (7.2–6.7%) in infants whose mothers received the vaccine during the specific stage of pregnancy. Common side effects experienced by adults may include fatigue, headache, nausea, muscle pain, and discomfort at the injection site.
Source: Pfizer, National Library of Medicine, Pfizer
