MenACWY vaccination campaign for adolescents in the Netherlands: Uptake and its determinants

Between 2015 and 2018 the incidence of meningococcal disease serogroup W increased tenfold in the Netherlands with the highest case fatality among adolescents and young adults. In 2018-2019 a national mass vaccination campaign, with recall after non-attendance, was implemented targeting 14-18-years old adolescents. This study estimated the MenACWY-vaccine uptake and investigated its determinants.

The uptake before the start of the vaccination campaign was estimated from the number of vaccines administered by Municipal Health Services and dispensed by public pharmacies, and within the campaign from the national vaccination register. Possible determinants of uptake after the first invitation and recall were investigated among the first group invited for vaccination (born in May-December 2004) using random forest classification analysis.

The uptake was 86% (of which 1.9% before the campaign) among all eligible adolescents and 88% among the first group invited, including 5% uptake achieved after the recall. The most important predictor of vaccination after the first invitation was parents' country of birth (lower uptake when parents were born abroad, range: 52%-Morocco to 88%-Netherlands). The most important predictors among those recalled were, respectively, distance to vaccination location (lower uptake with larger distance, range: 4-6%), percentage of votes for the conservative Christian (reformed) party in the municipality (lower uptake with higher percentage, range: 4-5%) and parents' country of birth (higher uptake when parents were born abroad, range: 4%-Netherlands to 11%-Syria).

The MenACWY vaccination campaign for adolescents achieved a high uptake, with little vaccine use before the campaign. Parents' country of birth, votes for the conservative reformed political party and distance to the vaccination location were the most important predictors of vaccination. The recall strategy enhanced the uptake and was valuable to diminish immunization disparities. Future vaccination campaigns should put more effort into reaching adolescents with immigrant parents.