Story at-a-glance
- Merck's respiratory syncytial virus (RSV) shot clesrovimab (Enflonsia) was approved even though 11.71% of babies in the trial experienced serious adverse events, including seizures, brain injury, and death
- Infants who got clesrovimab had a 350% higher risk of upper respiratory infections — exactly the type of illness this shot claims to prevent
- The injection is given in a single, fixed dose regardless of infant weight, putting smaller, younger babies at greater risk due to disproportionately high exposure
- Babies who received the shot had a threefold increase in severe neurological reactions compared to those given a placebo
- Only about 25 babies in the U.S. succumb to RSV each year, making the known risks of clesrovimab far outweigh the threat the virus poses to most children
