Winter is coming: so is RSV!!

As Europe braces for a surge in respiratory syncytial virus (RSV) during the coming winter months, public health authorities face a critical challenge: infants under six months of age are at especially high risk of developing severe RSV disease, including bronchiolitis, pneumonia, or even sepsis. Severe cases often require hospitalization or intensive care, placing a substantial burden on health systems.

RSV is among the most common causes of acute lower respiratory tract infection in young children, and even healthy infants can progress to life-threatening illness. According to global estimates, RSV leads to over 3.6 million hospitalizations and roughly 100,000 deaths annually in children under five, with the majority of fatalities occurring in low- and middle-income countries.¹

In Europe, immunization options now exist to mitigate this burden. Since 2022, two key preventive tools have been authorised: a long-acting monoclonal antibody administered to infants shortly after birth to provide passive protection through their first RSV season, and a maternal vaccine given during pregnancy to confer protective antibodies to the fetus.² Many European countries are already implementing these strategies — some offer universal protection to all babies born during RSV season, while others prioritize high-risk infants (such as those born prematurely or with chronic conditions).

RSV is also a prominent but under-recognized problem in India. Hospital- and community-based studies across the country (2007–2020) report RSV detection rates in young children (under five years) ranging from about 2 % to 62 %, with a predominance in infants under six months.³ A prospective surveillance study in rural northern India found that RSV accounted for nearly 20% of all acute medical hospitalizations among children under five, and was the most frequently detected virus in infants under one year, with incidence rates of approximately 99 per 10,000 child-years.⁴ Another hospital-based study in southern India reported RSV in 24.5% of children hospitalized for lower respiratory infection; most of these children were under two years, and a significant fraction required intensive care.⁵

Despite this, RSV remains underdiagnosed and underreported in India; many hospitals do not routinely test for it. This underlines a critical gap: without systematic surveillance, the true disease burden is obscured, and preventive efforts lag.

Protecting Infants: Prevention Strategies

Given the high vulnerability of young infants, several strategies can help reduce RSV risk:   

1. Surveillance and awareness: Strengthening laboratory-based RSV surveillance in India is essential. Clinicians need to recognize RSV as a likely cause of severe respiratory illness, even in previously healthy babies.

2. Maternal immunization: While RSV vaccines for pregnant people are in use in some countries, India has yet to widely adopt this strategy. Early evaluation of maternal vaccination could be cost-effective, especially given RSV’s large burden and the high cost of monoclonal antibody prophylaxis3.

3. Passive immunization: Long-acting monoclonal antibodies, such as nirsevimab, which are used in Europe and other settings, could be considered for high-risk infants, if approved and made accessible.

4. Basic preventive care: Promoting breastfeeding, minimizing infants’ exposure to sick contacts, ensuring good hand hygiene, and using measures such as mask-wearing for caregivers during RSV season are practical ways to reduce transmission risk.

To conclude RSV poses a serious threat to infants, particularly during the winter months in Europe and post-monsoon or early winter in countries like India. While Europe is increasingly deploying immunization strategies — namely, maternal vaccination and monoclonal antibodies — India still faces obstacles in surveillance, diagnosis, and access to prevention. Scaling up efforts to monitor RSV, improve awareness, and, when possible, use immunization tools will be key to protecting the most vulnerable infants from severe RSV disease.

References:

1. WHO. Respiratory Syncytial Virus (RSV) fact sheet.
   
   
2. Asseri AA. Respiratory Syncytial Virus: A Narrative Review of Updates and Recent Advances in Epidemiology, Pathogenesis, Diagnosis, Management and Prevention. Journal of Clinical Medicine. 2025 May 30;14(11):3880.
   
   
3. Ghia C, Rambhad G. Disease Burden Due to Respiratory Syncytial Virus in Indian Pediatric Population: A Literature Review. Clin Med Insights Pediatr. 2021 Jul 6;15:11795565211029250. doi: 10.1177/11795565211029250. PMID: 34285625; PMCID: PMC8264742.
   
   
4. Broor S, Dawood FS, Pandey BG, Saha S, Gupta V, Krishnan A, Rai S, Singh P, Erdman D, Lal RB. Rates of respiratory virus-associated hospitalization in children aged <5 years in rural northern India. J Infect. 2014 Mar;68(3):281-9. doi: 10.1016/j.jinf.2013.11.005. Epub 2013 Nov 21. PMID: 24269675; PMCID: PMC7112698.
   
   
5. Kini S, Kalal BS, Chandy S, Shamsundar R, Shet A. Prevalence of respiratory syncytial virus infection among children hospitalized with acute lower respiratory tract infections in Southern India. World J Clin Pediatr. 2019 Apr 9;8(2):33-42. doi: 10.5409/wjcp.v8.i2.33. PMID: 31065544; PMCID: PMC6477150.