Reactogenicity and medically attended adverse events following hexavalent vaccination: An observational prospective study

Abstract

Any vaccine related safety issue leads to loss of parents’ confidence in vaccines. This observational prospective study aimed to assess the reactogenicity and medically attended adverse events (MAEs) reported after the hexavalent vaccination (diphtheria-tetanus-pertussis toxoid, inactivated poliomyelitis virus, antigens against hepatitis B and Haemophilus influenzae type B polysaccharide). Children, vaccinated with the hexavalent vaccine in two general practitioner’s offices between March 2016 and April 2017 according to the national immunization schedule from Romania, were included in the study. Reactogenicity and MAEs were assessed for 4 days post-vaccination and during 6 months post-vaccination, respectively. A total of 211 children were included in the study. The hexavalent vaccine was administered alone (Hexa alone) in 255 visits and together with other paediatric vaccines (Hexa co-ad) in 101 visits. Pain was the most frequently reported solicited local symptom regardless if the hexavalent vaccine was administered alone or co-administered with other paediatric vaccines (26.1% vs. 31.3%). Fever was more frequently reported in Hexa co-ad group as compared to Hexa alone (28.1% vs. 13.7%). Infectious diseases were the majority of reported MAEs. 13 serious AEs and no death were recorded. Overall, this study confirmed the known safety profile of the hexavalent vaccine.