Meningococcal serogroup C vaccine: A pharmacovigilance point of view

Background: In October 2002, the Midi-Pyrenees centre of pharmacovigilance (Southwest of France) was in charge of an extensive pharmacovigilance follow-up of a campaign of meningococcal serogroup C vaccination performed in the Hautes-Pyrenees area. Objective: The purpose of this study was to evaluate the incidence, nature and seriousness of adverse drug reactions (ADRs) occurring during the 15 days after vaccination. Methods: 'Immediate' and 'late' ADRs were recorded. Results: Local immediate ADRs were mainly nonserious local or inflammatory responses with a favourable evolution. General immediate ADRs occurred in 198 subjects and were principally neurological in nature (54%, mainly headache). Moreover, 1529 subjects suffered from general late ADRs (i.e. general health status or neurological [headache] ADRs [41%]). The incidence of ADRs leading to hospitalisation or medical consultation was defined as 'very rare' (0.1% led to consultation and 0.03% to hospitalisation). Conclusion: These results underline that most of the ADRs occurring during the 15 days after meningococcal serogroup C vaccination were benign. This study shows that the methods used in France for pharmacovigilance studies of drugs can also be used for vaccines, especially for an intensive and prospective survey. Further pharmacoepidermological studies could be used after the pharmacovigilance survey to investigate the benefit/risk ratio in large populations.