Available Vaccines
Respiratory Syncytial Virus (RSV)
Introduction
Respiratory Syncytial Virus (RSV) is a leading cause of acute lower respiratory tract infections globally, not only in infants but is increasingly recognised as a major pathogen in older adults and high-risk groups. The RSV is a single-stranded RNS virus from Pneumovirus genus and Paramyxoviridae family with two serogroups A and B. Infections can lead to serious complications such as bronchiolitis and pneumonia, contributing to significant morbidity and mortality in adults aged 60 years and older, particularly those with comorbidities like chronic obstructive pulmonary disease (COPD), cardiovascular disease, and diabetes.
In Malaysia, RSV outbreaks are commonly observed during the monsoon seasons and contribute to seasonal strain on hospitals. Older individuals hospitalised with RSV are at risk of cardiovascular complications, while individuals with existing cardiovascular disease are at increased risk of hospitalisation with RSV.
Table 23.1 Vaccines Registered in Malaysia
Table 23.2 High-Risk Groups in Malaysia
Co-administration
RSV vaccines can be co-administered with other adult vaccines during the same visit.
Implication for Health Care Workers (HCWs)
While HCWs are at an increased risk of exposure, there is currently no evidence supporting RSV vaccination in HCWs. However, vaccination of older adults is expected to reduce RSV admissions and in turn, reduce the risk of RSV exposure among HCWs.
Evidence of Safety & Effectiveness
Clinical trials have shown high efficacy for both vaccines. Arexvy demonstrated an efficacy of 82.6% in preventing RSV lower respiratory tract disease in older adults, while Abrysvo showed a similar efficacy of 85.7%. Importantly, both vaccines significantly reduce the risk of hospitalisation due to RSV complications, which is critical for resource-limited healthcare settings. Real-world data from the United States and Europe indicate reductions in RSV-related hospitalisations and acute exacerbations of chronic conditions among vaccinated older adults. Immunogenicity studies show durable antibody responses for at least six months post-vaccination, with protection potentially extending up to three years.
Emerging data also suggest that RSV vaccination may reduce the severity and duration of illness in breakthrough infections.
RSV vaccination given to pregnant women produces passive immunity to the infant for up to six months, reducing the risk of hospitalisation with bronchiolitis among infants.
In adults, the most common undesirable effects (>10%) included headache, nausea and muscle pain at the injection site.
References
- Alfano, F., Bigoni, T., Caggiano, F. P., & Papi, A. (2024). Respiratory Syncytial Virus Infection in Older Adults: An Update. Drugs & Aging, 41(6), 487–505. https://doi.org/10.1007/s40266-024-01118-9
- Nguyen-Van-Tam, J. S., O’Leary, M., Martin, E. T., Heijnen, E., Callendret, B., Fleischhackl, R., Comeaux, C., Tran, T. M. P., & Weber, K. (2022). Burden of respiratory syncytial virus infection in older and high-risk adults: a systematic review and meta-analysis of the evidence from developed countries. European respiratory review : an official journal of the European Respiratory Society, 31(166), 220105. https://doi.org/10.1183/16000617.0105-2022
- Ivey, K. S., Edwards, K. M., & Talbot, H. K. (2018). Respiratory Syncytial Virus and Associations With Cardiovascular Disease in Adults. Journal of the American College of Cardiology, 71(14), 1574–1583. https://doi.org/10.1016/j.jacc.2018.02.013
- Woodruff RC, Melgar M, Pham H, et al. (2024). Acute Cardiac Events in Hospitalized Older Adults With Respiratory Syncytial Virus Infection. JAMA Intern Med, 184(6):602–611. https://10.1001/jamainternmed.2024.0212
- Wilson, E., Goswami, J., Baqui, A. H., Doreski, P. A., et al. (2023). Efficacy and Safety of an mRNA-Based RSV PreF Vaccine in Older Adults. The New England Journal of Medicine, 389(24), 2233–2244. https://doi.org/10.1056/NEJMoa2307079
- Walsh, E. E., Pérez Marc, G., Zareba, A. M., Falsey, A. R., Jiang, Q., Patton, M., Polack, F. P., Llapur, C., Doreski, P. A., Ilangovan, K., Rämet, M., Fukushima, Y., Hussen, N., Bont, L. J., Cardona, J., DeHaan, E., Castillo Villa, G., Ingilizova, M., Eiras, D., Mikati, T., RENOIR Clinical Trial Group (2023). Efficacy and Safety of a Bivalent RSV Prefusion F Vaccine in Older Adults. The New England Journal of Medicine, 388(16), 1465–1477. https://doi.org/10.1056/NEJMoa2213836
- Madhi, S. A., Polack, F. P., Piedra, P. A., Munoz, F. M., et al. (2020). Respiratory Syncytial Virus Vaccination during Pregnancy and Effects in Infants. The New England Journal of Medicine, 383(5), 426–439. https://doi.org/10.1056/NEJMoa1908380
- Molnar, D., La, E. M., Verelst, F., et al. (2024). Public Health Impact of the Adjuvanted RSVPreF3 Vaccine for Respiratory Syncytial Virus Prevention Among Older Adults in the United States.Infectious Diseases and Therapy, 13(4), 827–844. https://doi.org/10.1007/s40121-024-00939-w
- Mensah, A. A., Whitaker, H., Andrews, N. J., & Watson, C. H.(2025). Early impact of RSV vaccination in older adults in England. The Lancet, 405(10485), 1139-1140. https://doi.org/10.1016/S0140-6736(25)00346-0
- Use of RSV Vaccines in Adults Aged 60 years: Updated Recommendations of ACIP, CDC. USA, (August 2024). Morbidity and Mortality Weekly Report. Vol. 73 (32):696-702. https://www.cdc.gov/mmwr/volumes/73/wr/mm7332e1.htm