RSV Vaccines and the Elderly: A New Shield Against a Silent Killer?

Leon Wirz
Sep 29
4 min read

Published in Vaccines on May 5, 2024

Introduction

Respiratory syncytial virus (RSV) is a common respiratory virus that usually causes mild cold-like symptoms, but in vulnerable groups such as infants and the elderly it can lead to serious disease. In older adults, RSV is a major cause of lower respiratory tract infections, exacerbations of chronic conditions, and increased mortality. Globally, RSV is estimated to cause around 11 million cases, 800,000 hospitalizations, and more than 70,000 deaths each year in adults aged 60 and older in high-income countries . This burden is comparable to seasonal influenza — but less well recognized in public health planning.

For decades, vaccine development repeatedly failed due to weak immune responses in seniors. That is now changing. A systematic review and meta-analysis, published in Vaccines in May 2024, demonstrated that newly developed RSV vaccines can provide strong protection in older adults .

The Core Discovery

The study confirmed that novel vaccines targeting the prefusion F-protein — a viral surface protein essential for RSV entry into human cells — were particularly effective. In adults aged 60 and above, these vaccines reduced the risk of lower respiratory tract disease (LRTD, infections affecting the lungs and bronchi) by more than 80% in the first RSV season.

Crucially, the protection extended beyond one year, although it declined to about 60% in the second season. The analysis reported results with confidence intervals, confirming that the observed protection was robust.

How the Study Was Conducted

The team led by Matteo Riccò performed a systematic review and meta-analysis of randomized controlled trials (RCTs) on RSV vaccines, focusing on older adults (≥ 60 years).

They assessed:

Vaccine efficacy (VE) against RSV-related LRTD.
Hospitalization and severe disease outcomes.
Duration of protection across two or more seasons.
Safety and tolerability compared to placebo groups.

Pooling the results across trials provided a more precise estimate than any single study.

Key Findings

Strong efficacy – VE of ~81% (95% CI: 71–88%) against LRTD in the first season.
Waning immunity – VE dropped to ~61% (95% CI: 45–72%) in the second season.
Hospitalization reduction – Vaccinated seniors had significantly fewer RSV-related hospital admissions.
Acceptable safety profile – Adverse events were mostly mild (pain at injection site, fatigue), with no signal of severe side effects.

Limitations of the Study

Duration of protection – Protection wanes; booster strategies need further study.
Population studied – Mostly healthy older adults in high-income countries; frailer multimorbid patients remain underrepresented.
No long-term data – Effectiveness beyond three RSV seasons remains unknown.
Comparisons missing – More data needed on how RSV vaccines interact with influenza and COVID-19 vaccine programs.

Relevance for Switzerland

Switzerland faces rising risks due to demographic change:

By 2050, nearly one in three Swiss residents will be over 65 .
RSV hospitalizations can cost CHF 15,000–20,000 per case, especially when ICU stays are required .
At present, RSV vaccination is not included in compulsory health insurance.
The BAG is currently evaluating vaccines such as Abrysvo® (Pfizer) and Arexvy® (GSK) for older adults .

For insurers, the question will be whether covering RSV vaccines is cost-effective compared to unpredictable hospitalization costs.

Potential Impacts of a Successful Therapy

Hospital relief – Lower winter ICU pressure.
Public health benefit – Fewer severe RSV infections and secondary pneumonias.
Insurance perspective – High upfront vaccination cost vs. potential long-term stability in hospital expenditures.
Swiss biotech opportunity – With Lonza active in vaccine manufacturing, Switzerland could play a role in global RSV vaccine supply chains.

Risks

Boosters required – Annual vaccination may be needed, raising costs.
Equity concerns – If not reimbursed, access may be limited to wealthier seniors.
Real-world uncertainty – Effectiveness in frail multimorbid elderly could be lower than trial results.

Overall Assessment

RSV vaccines mark a turning point in protecting the elderly from a historically neglected pathogen. For Switzerland, adopting RSV vaccination as part of standard prevention would mean upfront investments, but potential long-term savings in hospital costs and improved quality of life for seniors. A cautious but proactive rollout, combined with real-world monitoring, appears the most balanced path forward.

What Comes Next

Ongoing European monitoring programs will provide real-world effectiveness data.
The BAG will decide on inclusion of RSV vaccination in the national immunization program.
Future studies will refine booster schedules and assess co-administration with influenza and COVID-19 vaccines.

RSV may not yet be as recognized as influenza in public health policy, but the data show that prevention in seniors could save both lives and significant healthcare resources.

References

Riccò M., et al. Efficacy of Respiratory Syncytial Virus Vaccination to Prevent Lower Respiratory Tract Illness in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Vaccines, May 2024. Link
Savic, M., Penders, Y., Shi, T., Branche, A., Pirçon, J.–Y. Respiratory syncytial virus disease burden in adults aged 60 years and older in high-income countries: a systematic literature review and meta-analysis. Influenza and Other Respiratory Viruses, February 2023 Link
Bundesamt für Statistik (BFS). Bevölkerungsszenarien für die Schweiz 2020–2050. 2025 update page. Link
Stucki, M., et al. Inpatient burden of RSV in Switzerland, 2003–2021: A nationwide analysis. Eurosurveillance, September 2024. Link
Bundesamt für Gesundheit (BAG) / EKIF. Impfempfehlungen: RSV bei älteren Erwachsenen (Bulletin 47/2024). November 2024. PDF Link