Adverse events following booster doses of diphtheria-tetanus-inactivated poliovirus and acellular pertussis vaccines for 4-year-old children in The Netherlands.

The aim of the study was to assess the incidence and severity of local reactions and systemic events among 4-year-old children receiving a fifth dose of diphtheria-tetanus-inactivated poliovirus (dT-IPV) and acellular pertussis (aP) vaccines. Of 810 children, 483 had no adverse events following immunization. Of the reported local reactions of 281 children, pain was the most frequent (n=246). Eighty-one children developed redness, and 54, swelling. Pain, reduced use of the arm, redness, and swelling occurred significantly more often at the dT-IPV injection site than at the aP injection site (p<0.05). Local reactions were mainly mild and transient. Among the 104 reported systemic events, fever was the most frequent (n=42). In general, the vaccinations for the 4-year-olds are well tolerated.