Comparison of the tolerability of newly introduced childhood vaccines in the Netherlands.

In 2011, the 7-valent conjugated pneumococcal vaccine (PCV7) was replaced by the 10-valent vaccine (PCV10) and universal hepatitis B vaccination has been introduced in the Netherlands. A questionnaire study was conducted to assess the tolerability of DTaP-IPV-Hib + PCV7 (PCV7-cohort), DTaP-IPV-Hib + PCV10 (PCV10-cohort), and DTaP-IPV-Hib-HepB + PCV10 (HepB-cohort). Parents were asked to report in questionnaires local reactions and systemic adverse events (AEs) before and after vaccination of their infant at 2, 3, 4, and 11 months of age. For 29.0 and 29.4% infants of the PCV7-cohort, at least one local reaction was reported in the week after the first dose of DTaP-IPV (left leg) and PCV-7 vaccination (right leg). Significantly more infants from the PCV10-cohort (45.1%, p < 0.001 and 44.6%, p < 0.001) and HepB-cohort (42.6%, p < 0.001 and 41.9%, p < 0.001) reported at least one local reaction. This effect was less pronounced after the successive doses. Most of the infants experienced at least one systemic AE, and after dose 4, this was higher for infants in the PCV10-cohort (65.9%, p = 0.047) and HepB-cohort (70.6%, p = 0.000) compared to the PCV7-cohort (62.3%). CONCLUSION: Addition of antigens to a vaccine resulted in a higher reactogenicity, but the AEs were in general mild and transient. What is Known: • Assessment of adverse events is crucial for achieving the highest safety in immunization programs, in order to inform public health actions and maintain public confidence in immunization programs. What is New: • Newly introduced vaccines DTaP-IPV-Hib-HepB and PCV10 are generally safe and well tolerated in infants. • These results are useful for information purposes and for monitoring variations in rates of AEs in the general population or in the target group over time.