The first months of life and its last years share the same fragility in the face of respiratory syncytial virus. Known to cause bronchiolitis in toddlers, RSV can also cause respiratory or cardiac complications in seniors, with a risk of loss of autonomy. The published data recall the extent of this health burden which goes far beyond pediatrics alone.
RSV, a well-known threat to infants
Among young parents, vigilance is already well established. An IPSOS study carried out in early 2026 among 500 pregnant women or those who have recently given birth shows that RSV is perceived as the most worrying infectious agent for 45% of them, a concern which reaches 54% in the third trimester of pregnancy. Conversely, older people often continue to underestimate the consequences of the virus.
The respiratory syncytial virus is the cause of the majority of bronchiolitis requiring hospital treatment. Most of the time, the infection resembles a common cold and progresses favorably. In some cases, the virus reaches the lungs of healthy newborns.
The consequences can then become more serious: breathing difficulties, hospitalizations and sometimes admissions to intensive care. Beyond the disease itself, this sudden deterioration in the health of babies also affects their parents and loved ones.
In France, the weight of RSV appears clearly in the figures. In 2021, more than 44,000 hospitalizations of newborns were attributed to it. More than 70% concerned children under six months old. The annual cost of these hospitalizations is estimated at 138 million euros.
The virus does not always stop at the acute episode. Indeed, it represents an increased risk of recurrent respiratory episodes or asthma later in childhood.
Among seniors, an impact still largely underestimated
In older adults, RSV often remains invisible behind other respiratory infections. Cough, fatigue or shortness of breath resemble many winter pathologies. Aging of the immune system can also reduce certain signs such as fever.
Result: the virus is rarely searched for and its real weight remains difficult to measure. However, a study estimates that the actual number of hospitalizations could be 2.2 to 6.4 times higher than the observed figures.
The people most at risk are those over 75, but also those over 65 with chronic pathologies such as COPD, asthma, cardiovascular disease or diabetes.
RSV can then cause cardio-respiratory exacerbations, general weakness and sometimes loss of autonomy, an impact comparable to that observed with the flu.
An economic weight close to that of the flu
Among seniors, respiratory syncytial virus accounts for approximately 25,000 hospitalizations each year. One study even indicates that hospital stays can last longer than those related to the flu.
A meta-analysis covering the period 2000-2019 estimates that RSV is responsible for 5 to 7.8% of symptomatic respiratory infections among older people in Europe, with a mortality rate reaching 8%.
The economic cost follows the same trajectory. Respiratory and cardiac hospitalizations attributable to RSV among those over 65 would represent 104.5 million euros per year, a level very close to the 102.1 million euros attributed to influenza over the period 2010-2020.
Faced with this circulation of the virus, hygiene measures remain a lever for prevention: washing hands, wearing a mask in the event of symptoms and limiting contact when a person is sick.