Implementation of monoclonal antibodies against seasonal outbreaks of respiratory syncytial virus: impact on incidence and mortality

Acute lower respiratory infections (ALRI) in children under 5 years old represent a significant cause of morbidity and mortality worldwide, particularly in low- to middle-income countries. ALRI may be caused by numerous microorganisms, with viruses being the most frequent culprits. Preventive measures have been taken to decrease the incidence and mortality of the most prevalent causative agents, namely respiratory syncytial virus (RSV), influenza A and B, and some adenoviral subtype. Nonetheless, only the vaccines for type A and B influenza are currently available and recommended for use in children. Among these viruses, RSV stands out as the leading cause of ALRI and is also responsible for a significant proportion of hospitalizations related to bronchiolitis and pneumonia. Another distinctive aspect of RSV is its seasonal pattern, typically peaking during colder months in temperate regions, and during the rainy season in tropical areas. Given its predictive epidemiological behavior, other measures have been developed to decrease its incidence and morbimortality during this specific time-span. Available evidence of high and moderate certainty has shown that monoclonal antibodies (mAbs) significantly reduce the rates of RSV infection as well as the need for hospitalization, need for ICU admission, and RSV-associated mortality. Motavizumab, nirsevimab, palivizumab, and suptavumab are some of the available alternatives to decrease the global impact of RSV and ALRI. The aim of this review is to analyze the mechanism of action of mAbs to decrease the burden of RSV in children’s health, analyzing primary outcomes such as mortality, hospital admissions, and ICU admissions; moreover, financial aspects will also be discussed.