Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections in infants and children. It is a seasonal virus, with peak infection rates in temperate climates during the cold season and in tropical climates during the rainy season. High-risk groups for severe RSV disease include infants under six months, preterm infants with or without chronic lung disease, infants with congenital heart disease, immunodeficiency, cystic fibrosis, and neuromuscular diseases. Mortality rates are generally low in healthy infants but increase in those with underlying conditions. RSV can lead to recurrent wheezing resembling asthma, persisting into adolescence. Currently, there is no RSV vaccine, but several candidates are under development. Palivizumab, a monoclonal antibody, is the only available immunoprophylaxis for high-risk infants, reducing RSV infection burden in selected groups. RSV causes significant healthcare costs, with hospitalizations and inpatient care being major contributors. In 2005, an estimated 33.8 million RSV-related acute lower respiratory infections occurred globally, with 3.4 million requiring hospitalization. Mortality rates vary, with higher rates in infants with chronic lung disease or congenital heart disease. Despite reduced mortality over the years, pulmonary hypertension remains a significant risk factor. Post-RSV wheezing disorder is common, with some children developing reactive airway disease or persistent lung function abnormalities. RSV vaccine development is ongoing, with various approaches including live attenuated vaccines, recombinant viruses, and gene-based vectors. Recent trials show promise, but a safe and effective vaccine is still needed. Palivizumab has been shown to significantly reduce RSV-related hospitalizations in high-risk infants. A large phase III trial demonstrated a 55% reduction in hospitalizations. Guidelines for palivizumab use are based on recommendations from the American Academy of Pediatrics. While palivizumab is effective, studies on its use in certain conditions are still pending. Motavizumab, a newer monoclonal antibody, showed noninferiority to palivizumab in reducing RSV hospitalizations. Pharmacoeconomic analyses suggest palivizumab is cost-effective for high-risk infants. Despite high costs, RSV-related healthcare costs are similarly high in this population. Until an effective RSV vaccine is available, measures such as immunoprophylaxis with monoclonal antibodies can help reduce RSV-related morbidity and mortality.Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections in infants and children. It is a seasonal virus, with peak infection rates in temperate climates during the cold season and in tropical climates during the rainy season. High-risk groups for severe RSV disease include infants under six months, preterm infants with or without chronic lung disease, infants with congenital heart disease, immunodeficiency, cystic fibrosis, and neuromuscular diseases. Mortality rates are generally low in healthy infants but increase in those with underlying conditions. RSV can lead to recurrent wheezing resembling asthma, persisting into adolescence. Currently, there is no RSV vaccine, but several candidates are under development. Palivizumab, a monoclonal antibody, is the only available immunoprophylaxis for high-risk infants, reducing RSV infection burden in selected groups. RSV causes significant healthcare costs, with hospitalizations and inpatient care being major contributors. In 2005, an estimated 33.8 million RSV-related acute lower respiratory infections occurred globally, with 3.4 million requiring hospitalization. Mortality rates vary, with higher rates in infants with chronic lung disease or congenital heart disease. Despite reduced mortality over the years, pulmonary hypertension remains a significant risk factor. Post-RSV wheezing disorder is common, with some children developing reactive airway disease or persistent lung function abnormalities. RSV vaccine development is ongoing, with various approaches including live attenuated vaccines, recombinant viruses, and gene-based vectors. Recent trials show promise, but a safe and effective vaccine is still needed. Palivizumab has been shown to significantly reduce RSV-related hospitalizations in high-risk infants. A large phase III trial demonstrated a 55% reduction in hospitalizations. Guidelines for palivizumab use are based on recommendations from the American Academy of Pediatrics. While palivizumab is effective, studies on its use in certain conditions are still pending. Motavizumab, a newer monoclonal antibody, showed noninferiority to palivizumab in reducing RSV hospitalizations. Pharmacoeconomic analyses suggest palivizumab is cost-effective for high-risk infants. Despite high costs, RSV-related healthcare costs are similarly high in this population. Until an effective RSV vaccine is available, measures such as immunoprophylaxis with monoclonal antibodies can help reduce RSV-related morbidity and mortality.