Adjuvanted RSVPreF3 Vaccine Could Prevent RSV Infection Among Older Adults

The RSVPreF3 vaccine (Arexvy, GSK) could significantly reduce the burden of respiratory syncytial virus (RSV) among US adults 60 years and older, according to research published in Springer Link.

The findings could help further efforts to vaccinate older individuals who could experience acute respiratory illness (ARI) caused by RSV infection. The highly contagious infection could lead to substantial morbidity and mortality in older adults and adults with chronic conditions, according to study authors. In a previously conducted cohort study, the researchers found an estimated 177,525 RSV-related hospitalizations and 14,000 RSV-related deaths each year among US adults 65 years and older.

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Cases of RSV-ARI are defined as lower respiratory tract disease (RSV-LRTD) or upper respiratory tract disease (RSV-URTD). Importantly, RSV-URTD usually presents with milder symptoms, but older adults infected with RSV have been linked with more severe symptoms and outcomes once infected, noted study authors.

Approved by the FDA in 2023, both RSVPreF (Abrysvo, Pfizer) and RSVPreF3 have shown effectiveness against RSV infection by targeting the F glycoprotein. However, the study authors noted that RSVPreF3 is more effective for older adults because it could boost antibody and cellular responses that aid age-related immune system weakening.

The researchers created a static, multi-cohort Markov model to assess the adjuvanted RSVPreF3 vaccine in relation to morbidity and mortality among cases of symptomatic RSV-ARI. The study compared vaccination with RSVPreF3 versus no vaccination among US individuals aged 60 years and older.

The study authors noted that the individuals were divided into 7 age specific cohorts (60 to 64, 65 to 69, 70 to 74, 75 to 79, 80 to 84, 85 to 89, and ≥ 90 years), to allow for greater assessment of varying risk of key outcomes. A 3-year time horizon was included in the study to test the adjuvanted RSVPreF3 efficacy against RSV for up to a 3-year period.

Key outcomes in the study included the overall number of symptomatic RSV-ARI cases (both RSV-URTD and RSV-LRTD); the number of hospitalizations, outpatient, and ED visits; the number of antibiotic prescriptions; and complications and death. Researchers then calculated each outcome with the adjuvanted RSVPreF3 versus no vaccination.

The results found that among 56,654,023 older adults vaccinated with RSVPref3 at the start of the study, the vaccine was estimated to prevent almost 3 million symptomatic RSV-ARI cases over 3 years. Among individuals who did not receive a vaccine, there were more than an estimated 11 million symptomatic RSV-ARI cases over the 3-year time, according to study authors.

“In addition, vaccination would result in 203,891 avoided RSV-related hospitalizations, 164,060 avoided ED visits, 1,577,586 avoided outpatient visits, 1,343,915 avoided antibiotic prescriptions, 321,019 avoided pneumonia cases, and 16,660 avoided deaths,” said the study authors, in a press release.

However, the study authors noted that most of decrease in RSV burden was accomplished in the first year following the vaccination.

The findings suggest that the adjuvanted RSVPreF3 vaccine could prevent nearly 3 million symptomatic RSV-ARI cases among US older adults over 3 years’ time. However, the study authors noted that to achieve this decrease in burden, older individuals must be supported to receive their RSV vaccine to promote healthier outcomes.

Reference

Public Health Impact of the Adjuvanted RSVPreF3 Vaccine for Respiratory Syncytial Virus Prevention Among Older Adults in the United States. Springer Link. March 20, 2024. Accessed March 27, 2024. https://link.springer.com/article/10.1007/s40121-024-00939-w.