A phase 2 randomized controlled trial of a multicomponent meningococcal serogroup B vaccine (I): efects of prophylactic paracetamol on immunogenicity and reactogenicity of routine infant vaccines and 4CMenB

The novel meningococcal serogroup B vaccine (4CMenB, Bexsero®), recently approved in Europe and Australia, may soon be included in routine infant immunization schedules, subject to guidance from national or regional recommending bodies. In the development of 4CMenB and consistent with other newly introduced vaccines, clinical studies have shown concomitant administration with routine infant vaccines induces an incremental increase in some reactions, including fever. As this may hinder acceptability, we examined the impact of prophylactic paracetamol on the occurrence of fever and other solicited reactions, as well as the immune responses to study vaccines, in a prospectively designed study. 4CMenB was administered as a 4-dose series at 2, 3, 4, and 12 months of age concomitantly with routine infant vaccines: DTaP-HBV-IPV/Hib and PCV7, with or without prophylactic paracetamol; a third group received MenC vaccine. Immune responses to 4CMenB were not decreased by the use of paracetamol prophylaxis and there were no clinically relevant effects on immune responses to routine vaccines. Occurrence of fever was higher in infants co-administered with 4CMenB compared with those given MenC vaccine, but was significantly decreased by prophylactic paracetamol, as were other solicited reactions to vaccination, both local and systemic. Co-administration of 4CMenB had an acceptable tolerability profile, with no withdrawals due to vaccination-related adverse events. Inclusion of 4CMenB in routine infant immunization schedules will be a major advance in the control of meningococcal disease, and our study indicates that by using paracetamol prophylaxis, post-vaccination reactions are reduced without clinically relevant negative consequences on vaccine immunogenicity.