The news of the EMA recommendation for approval of nirsevimab (Beyfortus) is good news for the following reasons. Firstly, because respiratory syncytial virus (RSV) infections cause a considerable burden of disease worldwide - there are numerous studies quantifying this - it affects all ages, but the severe forms (hospitalisation and deaths) are concentrated in young infants and the elderly. 

In the paediatric age group, severe infection particularly affects infants in the first 3-6 months of life, most of whom are previously healthy infants, although those born prematurely and those with, for example, congenital cardiac anomalies are more vulnerable. While mortality is concentrated in resource-poor countries, in middle- and high-income countries, the infection also has a very special impact. 

In our environment it is typically a seasonal infection, so that the vast majority of cases occur between November and February and the annual peak incidence of this infection is unpredictable and sets in very quickly. The consequence of this is that during the weeks that this peak lasts, Primary Care and the hospital services affected (emergency, paediatric hospitalisation and paediatric intensive care) are usually, year after year, saturated to significant levels, which sometimes have even interfered and forced to restrict attention to other needs.  

So much for the reasons related to the burden of disease, its particular form of presentation and the consequences for the health system. Secondly, it should be noted that to date there is only one prevention measure available in infants, another monoclonal antibody -palivizumab, Synagis- with very notable limitations in terms of usefulness, in addition to its high cost. In fact, its very limited indications and dosage (complicated, as it requires repeated doses) mean that, while its impact at the individual level is possibly relevant for those who receive it, at the population level it is almost irrelevant and costly. 

In this context, and until a vaccine that reduces the risk of RSV infection in infants arrives - we shall see if it does - the availability of a product such as nirsevimab, with the potential to prevent it and with a simple dosage, is great news. It is also a monoclonal antibody, but appears to successfully overcome some of the limitations of the only one available so far, palivizumab. 

According to the results of the clinical trials that led to the approval of Beyfortus, the product is effective and safe, and requires only one dose before the start of each season. We still need to know the details of the technical data sheet and the position of the AEMPS and the Ministry of Health on its indications in the National Health System (prevention in infants at higher risk or in healthy children), but the availability of nirsevimab will provide a novel tool for the prevention of RSV infection in infants. 

If expectations are confirmed, it could have a considerable impact on the health of the children who receive it, of particular interest to the most vulnerable (individual benefit) and relieving the health system of a disease with the potential to overwhelm it (population benefit).