Vaccination against Respiratory Syncytial Virus (RSV): Does it help against hospitalization in people aged 60 or older? — INFOMED

Vaccination for the end of life

In June 2023, the United States CDC recommended an RSV vaccine for adults aged 60 years and older, based on its effectiveness in clinical trials to prevent lower respiratory disease. Soon after, the Ministry of Health and ANMAT in Argentina did the same.

In addition, this vaccine is recommended for women in the last stage of pregnancy, to protect unborn children in the first 6 months of life.

These pre-approval trials were not powered to assess efficacy against RSV-related hospitalization. In addition, they excluded immunocompromised patients, and did not represent other groups at higher risk of severe illness from this virus, including adults aged 75 years and older.

A new study

A group of researchers from the United States evaluated the effectiveness of the RSV vaccine against RSV-related hospitalizations among adults 60 years of age or older in the first season of its use. They included adults aged 60 years or older hospitalized with severe respiratory disease in the analysis.

They conducted a case-control design in hospitals in a study network of 19 states. It was conducted between 1 October 2023 and 31 March 2024.

All were clinically tested for respiratory viruses within 10 days of illness onset. Nasal swabs were obtained and routinely tested by PCR for RSV, SARS-CoV-2, and influenza.

The “case” patients were those who tested positive for RSV, and the “control” patients were those who tested negative for RSV, SARS-CoV-2 and influenza.

RSV vaccination status was determined from electronic medical records, vaccination records, and self-report. Patients were stratified by age group (60-74, and ≥75 years).

The results: What did they find in this study?

In total they included 2,978 adults aged 60 or over:

• 367 (12.3%) were “case” patients, with RSV infection
• 2611 (87.7%) were “control” patients.

The median age was 72 (66-80) years. The median Charlson Comorbidity Index (CRI) score was 5 (4-7) and 720 (24.2%) were unprotected. Among the 288 RSV “case” patients in whom the viral subtype was known, 210 (72.9%) were RSV B.

A total of 9 of 367 (2.5%) case patients and 256 of 2,611 (9.8%) control patients received the vaccine, with a median interval between vaccination and disease onset of 84 (54-125) days.

Compared with unvaccinated patients, vaccinated patients were more often older (median age, 75 vs. 72 years), white (82.6% vs. 60.7%), and vaccinated (31.7% vs. 23.4%).

Vaccine effectiveness against RSV-related hospitalization was 75%, for all ages.

The conclusions: What does this study leave us?

Among adults aged 60 and older in 19 US states, the RSV vaccine was associated with a lower risk of hospitalization for the disease compared to patients who did not receive the vaccine.

These findings provide evidence of vaccine protection against RSV-related hospitalizations, of which approximately 60,000 to 160,000 occur annually among US adults age 65 and older.

In addition, they show that the vaccine provides protection in a population that represents those most at risk of severe RSV infection, including adults 75 years of age and older, and those who are protected by protection.

In June 2024, CDC updated its RSV vaccination guidelines for older adults and recommended that all adults age 75 and older, and those age 60 to 74 who are at greatest risk for severe illness, receive the vaccine. RSV, one single dose of RSV vaccine. This study provides initial data to inform ongoing risk-benefit analyzes of RSV vaccines.