Comparison of Postvaccination Fever between Single and Multiple Vaccines using Patient-Generated Health Data: A Retrospective Observational Study (Preprint)

Abstract

BACKGROUND Multiple vaccinations have been practiced widely in children to reduce hospital visits and the number of mental distresses ahead of vaccinations. However, in practice, how the fever patterns differ between multiple vaccinations and single vaccination is unknown. OBJECTIVE We investigated the postvaccination fever patterns of six vaccines—diphtheria/tetanus/pertussis, pneumococcus, Haemophilus influenzae B, polio, rotavirus, and influenza—recommended for children aged 2-6 months in the National Immunization Program of Korea by collecting logs of registered users of a mobile application. METHODS Multiple vaccinations were defined as simultaneous administration of ≥2 of the six vaccines. Further, multiple vaccination cases were divided into vaccination with (multiple-in) and without (multiple-out) the vaccine of interest. Postvaccination fever (≥38.0 °C) for each vaccine within 72h after vaccination was compared among single, multiple-in, and multiple-out groups according to antipyretic use. RESULTS In DTaP with antipyretics, single vaccination had similar the duration time (hour) of postvaccination fever to multiple-in, however multiple-in lasted about an hour longer than multiple-out. In PCV with and without antipyretics, single vaccination had similar the onset time when the first fever (≥38.0℃) occurred after vaccination to multiple-in, however the onset time of multiple-in was 5 to 7 hours faster than multiple-out. CONCLUSIONS Multiple vaccinations did not induce more severe fever or have rapid onset compared with a single vaccination. The post-vaccination fever patterns shown in single vaccination also appeared in multiple vaccinations including the vaccine. CLINICALTRIAL Not indicated