Do not give prophylactic paracetamol to reduce vaccine reactions

The pain and fever that may occur after vaccination can be attenuated by administering paracetamol at the time of immunization (1-3). However, this practice may be associated with decreased vaccine response (4).

The effects of prophylactic paracetamol on fever and immunogenicity were evaluated in a multicenter, open-label trial in which 459 infants (aged 9 to 16 weeks at study entry) were randomly assigned to receive paracetamol at the time of vaccination and for the next 24 hours or no prophylaxis before primary and booster immunizations (4). Primary immunizations consisted of 10-valent pneumococcal conjugate vaccine, nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), and hexavalent diphtheria-tetanus-acellular-pertussis-hepatitis B-inactivated polio-H. influenzae type b vaccine (DTaP-HBV-IPV/Hib) at three, four, and five months, and oral rotavirus vaccine at three and four months. Booster immunizations consisted of PHiD-CV and DTaP-HBV-IPV/Hib at 12 to 15 months of age.

Fewer children who received paracetamol had fever >38ºC (42 versus 66 percent and 36 percent versus 58 percent after primary and booster immunization, respectively). However, there was no difference between groups in occurrence of fever ≥39.5ºC (<1 to 2 percent) or fever requiring medical attention.

The vaccines were highly immunogenic in both groups, with at least 96 percent of children achieving protective levels of antibody for all antigens. However, prophylactic paracetamol was associated with lower geometric mean antibody titers (GMT) to pneumococcus, Haemophilus influenzae, pertussis, diphtheria, and tetanus after the primary series and lower GMT to pneumococcus, Haemophilus, and tetanus after the booster doses.

References

1.        Ipp MM, Gold R, Greenberg S, et al. Acetaminophen prophylaxis of adverse reactions following vaccination of infants with diphtheria-pertussis-tetanus toxoid-polio vaccine. Pediatr Infect Dis J 1987;6:721-5.

2.        Uhari M, Hietala J, Viljanen MK. Effect of prophylactic acetaminophen administration on reaction to DTP vaccination. Acta Paediatr Scand 1988;77:747-51.

3.        Long SS, Deforest A, Smith DG, et al. Longitudinal study of adverse reactions following diphtheria-tetanus-pertussis vaccine in infancy. Pediatrics 1990;85:294-302.

4.        Prymula R, Siegrist CA, 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. Lancet 2009;374:1339-50.