Poor adherence to population-based vaccination in two counties after meningococcal B:14:P1.7,16 outbreak: an illustration of the growing vaccine hesitancy in France.

Background: Neisseria meningitidis is a virulent bacteria provoking outbreaks of invasive meningococcal disease (IMD) that authorities may try to control with population-based vaccinations. Such campaigns are most often thoroughly followed. We assess the response of poor adherence during a population-based vaccination after a meningococcal B:14:P1.7,16 outbreak.

Methods: Between July, 2012, and April, 2013, six cases including one fatality of invasive meningococcal disease related to N. meningitidis B:14:P1.7,16/ST32 were reported in two neighboring counties. A vaccination campaign with MenBVac targeting 6911 inhabitants was implemented. People entering the vaccination schedule from January 2014 received 4CMenB.

Results: The number of immunized patients proved to be low, with 1721 (24.1%) receiving at least one dose out of 5069 doses administered. However, the incidence of IMD in the zone dramatically fell, with only one purpura fulminans case in June 2014 with a good outcome. The campaign was stopped after 1 year and a 2-year monitoring period was implemented until June, 2016, with no new cases.

Conclusions: This outbreak probably self-terminated in a context of a low incidence of serogroup B IMD during 2014 in France. Poor adherence illustrates the growing vaccine hesitancy in France. Similar campaigns will have to be thoroughly planned and implemented in terms of timing, modalities of injections, and mass communication.