A year has passed since publication of the Pyrmula et al study, which concluded that prophylactic antipyretics before vaccination should not be routine. The researchers came to this conclusion because they found reduced antibody responses to several vaccine antigens in children who received antipyretics, even though the vast majority of children studied (those given antipyretics and those not given antipyretics) had antibody titers well within the protective ranges.
A year has passed since publication of the Pyrmula et al1 study, which concluded that prophylactic antipyretics before vaccination should not be routine. The researchers came to this conclusion because they found reduced antibody responses to several vaccine antigens in children who received antipyretics, even though the vast majority of children studied (those given antipyretics and those not given antipyretics) had antibody titers well within the protective ranges.
A response to The Lancet article in AAP News stated that “pediatricians should be comfortable that this study’s results should not prevent the use of antipyretics either prophylactically or therapeutically for managing fever and discomfort,” and “if prophylactic antipyretics have an impact on the immune response, experience has not shown it to be clinically relevant.”2 At that time, our clinic opted to continue our routine of offering antipyretics before vaccination. Our pediatric group was concerned about parents’ reactions if we abruptly changed our long-standing routine. We were also concerned about the increased episodes of fever that would follow vaccination. It has been found that prophylactic administration of antipyretics at the time of vaccination do significantly decrease febrile episodes.1 Would there be increased visits to acute care clinics or emergency departments? Would there be more aggressive evaluations for these fevers, including blood draws and straight caths for urine collection, or even hospital admissions? How would these increased episodes of fever affect the parents’ future acceptance of vaccination?
After more deliberation among our pediatric providers in the past month, we’ve changed our routine and now no longer routinely recommend the use of prophylactic antipyretics. We do make them available when a parent insists. A major influence on this change was a message from a CDC broadcast in August 2010, which indicated that “evidence does not support use of antipyretics before or at the time of vaccination” and “studies have not demonstrated antipyretics to be effective in the prevention of febrile seizures.” The CDC also stated that “all recommendations for prophylactic use of acetaminophen or other analgesics before or at the time of vaccination are being removed, as they have been from the AAP Red Book.”3
Since our decision to discontinue prevaccination prophylactic antipyretics, vaccine counseling takes longer, because we delicately explain the reasoning behind the no-prophylactic antipyretics stance. So far, in general, almost all parents have accepted the change without question. A handful of parents have demanded prophylactic antipyretics or have been quite upset, confused, or even irate that this change was even being suggested to them. It’s too early to give an update about any increased episodes of fevers or trips to the emergency department and any adverse effects on parental acceptance of future vaccination. Time will tell whether it will further hurt the reputation of vaccines.
Prymula R, Siegrist C, Chlibek R et al. Effect of prophylactic paracetamol administration at time of vaccination on febrile reactions and antibody responses in children: two open-label, randomised controlled trials.
Brady MT, Swanson JT of AAP Committee on Infectious Disease and AAP Committee on Practice and Ambulatory Medicine. More study needed on antipyretics’ effect on vaccine responses.
Department of Health and Human Services Centers for Disease Control and Prevention. Immunization Update 2010 Broadcast: Q & A’s. Available at:
Accessed October 29, 2010.