The effect of antipyretics on immune response and fever following receipt of inactivated influenza vaccine in young children

While antipyretic analgesics are widely used to ameliorate vaccine adverse reactions, their use has been associated with blunted vaccine immune responses. Our objective was to review literature evaluating the effect of antipyretic analgesics on vaccine immune responses and to highlight potential underlying mechanisms. Observational studies reporting on antipyretic use around the time of immunization concluded that their use did not affect antibody responses. Only few randomized clinical trials demonstrated blunted antibody response of unknown clinical significance. This effect has only been noted following primary vaccination with novel antigens and disappears following booster immunization. The mechanism by which antipyretic analgesics reduce antibody response remains unclear and not fully explained by COX enzyme inhibition. Recent work has focused on the involvement of nuclear and subcellular signaling pathways. More detailed immunological investigations and a systems biology approach are needed to precisely define the impact and mechanism of antipyretic effects on vaccine immune responses.

No abstract

In children, fever is a symptom of a wide spectrum of diseases, ranging from common self-limiting viral upper respiratory tract infections to serious life-threatening diseases. The aim of the diagnostic procedure is to identify the cause of fever, determine indications for outpatient treatment, plan the appropriate pharmacological therapy or reveal the need for hospitalisation. Paracetamol and ibuprofen are antipyretics recommended for symptomatic treatment of children; however, the medications should not be used in combination or alternately, except in specific clinical situations. The drugs may be applied to treat fever and topical reactions after vaccination, but not prophylactically in order to reduce the incidence of fever or local discomfort after vaccination. Both medications can be used in patients with asthma, with the exception of intolerant children. Children with confirmed or suspected COVID-19 may be treated with paracetamol and ibuprofen in accordance with clinical indications and dosage recommendations.