Post-vaccination fever occurs in up to 40% of infants receiving routinely recommended childhood vaccinations. Although serious events are rare, post-vaccination fever causes discomfort for the child, can lead to medical utilization, can rarely result in febrile seizure, and can cause a working parent to miss time from their job to care for a febrile infant who cannot attend day care. The benefits of acetaminophen prophylaxis for infants receiving current vaccinations, in terms of reduction of discomfort for the child, improvement of quality-of-life indicators for the parent, or reduction of medical utilization, have not been measured. This randomized, blinded, placebo-controlled trial will assess the efficacy of prophylaxis with acetaminophen in prevention of fever following routine childhood immunizations.
