Fever over 100°F following multiple infant vaccinations is rare
Research Activities, December 2010, No. 364
Between 1991 and 2000, the number of recommended vaccines for children increased from 7 or 8 to up to 15. As the number of vaccinations increased, parents and physicians expressed concerns about their safety. Researchers decided to investigate whether changes in vaccine policy that increased the number of recommended vaccinations a child could receive were associated with an increased risk of medically attended fever (100.4°F or higher). They discovered that for every 1,000 vaccination visits, only 6.4 medically attended fevers were reported in the week following immunization.
Some of the changes to vaccination policy between 1991 and 2000 were: addition of Haemophilus influenzae type B flu vaccine, adoption of a universal hepatitis B vaccination recommendation, addition and withdrawal of oral rotavirus vaccine, and addition of a pneumococcal conjugate vaccine.
The researchers evaluated rates of medically attended fever after vaccination in the population of two large provider groups. Included in the study were 37,504 infants and 158,518 vaccination visits. This study is unique in using temperatures routinely recorded in the electronic medical record to collect information on fever. The findings provide reassurance that increases between 1991 and 2000 in the number of vaccines for routine use among children were not associated with increases in medically attended fever following vaccination in routine practice. This study was supported in part by the Agency for Healthcare Research and Quality (HS02819).
See "Multiple vaccinations and the risk of medically attended fever," by Nancy D. Lin, M.S., Sc.D., Ken Kleinman, Sc.D., K. Arnold Chan, M.D., Sc.D., and others in Vaccine 28, pp. 4169-4174, 2010.