Flu vaccine does not increase fever frequency when added to the 12- to 16-month vaccine line-up

Référence

Walter EB, Klein NP, Wodi AP, et al. Fever after influenza, diphtheria-tetanus-acellular pertussis, and pneumococcal vaccinations. Pediatrics 2020;145(3):e20191909.

Sommaire

These researchers evaluated 206 children aged 12 to 16 months (median age = 14.6 months) to this open (nonmasked) study. The children were randomized, using concealed allocation, into a simultaneous or sequential group. The simultaneous group received PCV13, DTaP, and IIV4 at visit 1 and no vaccines at visit 2. The sequential group received PCV13 and DTaP at visit 1 and IIV4 at visit 2. At the first visit, most children (89%) received at least one other vaccine in addition to those studied, including Hib conjugate vaccine (78%), measles, mumps, rubella, and varicella (34%), and hepatitis A (40%). By my count, this means the typical child received as few as 18 antigens and as many as 27 antigens at one time. Participants were monitored for fever (38°C) and antipyretic use during the 8 days after the visits. The addition of the influenza vaccine to the mélange of antigens did not increase the likelihood of fever (8.1% in the simultaneous group and 9.3% in the sequential group). Even though few children (8% in each group) had a fever in the first 2 days after visit 1, more children in the simultaneous group received an antipyretic dose for any reason (37.4% vs 22.4%; P = .02). This may be due to increased fussiness or be a testament to anticipatory anxiety or the power of suggestion. That the study took 1.5 years to enroll this many patients at 2 different sites tells me the authors had a hard time getting clinicians or parents to participate, thereby skewing the study participants to those whose clinicians and parents were not unduly concerned about vaccine safety.