A study that was published this morning in which Lancet Child and Young Healthannounces that the monoclonal antibody, Nirsevimab prevents serious infections with Syncytial Viruse in infants. In a great overview of the published evidence, epidemiologists from the University of Toronto and York University in Toronto, how effective nirsevimab was prescribed in the community under real conditions.
According to the researchers based in Toronto, these observation results strengthen clinical studies that support the use of the drug to treat the breathing virus. The researchers were not sure whether the drug that the RSV virus is supposed to catch and block in “real” environments outside the strictly controlled environment would work. According to the researchers, this newly combined data applies to the routine use of Nirsevimab in children who are vaccinated too young against RSV.
Respiration syncytial virus is the most common cause of the hospital stay of infants in the United States. According to the CDC, 58,000 to 80,000 children under the age of five are taken to the hospital with the illness every year. Infants, premature born children, people with diseases who influence the heart and lungs – for example cystic fibrosis, children with a weakened immune system and children with neuromuscular diseases that make swallowing difficult are particularly at risk. While vaccines are very effective to prevent the hardest cases of infection, children who are too young to be vaccinated or have affected the immune systems are currently not well protected.
The researchers combined the results of 27 studies that were carried out in Italy, France, Spain, Luxembourg and the USA, and show that the use of the monoclonal antibody base reduced the hospital stays for RSV by up to 83%in infants.
At the more detailed level, the researchers came to the conclusion that in children under one year, intensive admissions were reduced by 81%and the respiratory tract infections by 75%by 81%. At RSV, the drug was somewhat effective and prevented by 83% of the expected hospital stays in connection with RSV in babies under three months in infants that are older than three months.
Monoclonal antibody medication such as Nirsevimab are laboratory antibodies to imitate our immune system. Instead of using a vaccine to help the immune system to detect and combat RSV, monoclonal antibodies will arrive there by binding to the virus particles and preventing them from infecting cells. For people who have no natural antibodies to RSV – like very young babies, the monoclonal stocks act to combat the virus while the immune system catches up.
Sumsuzzman D, Wang Z, Langley JM, Moghadas SM. Real effectiveness of the effectiveness of nirsevimab against respiratory syncytial virus diseases in infants: a systematic review and meta-analysis. May 1, 2025.