Assessing the Role of Infant and Toddler MenACWY Immunisation in the UK: Does the Adolescent MenACWY Programme Provide Sufficient Protection?

A combined type b (Hib)/meningococcal serogroup C (MenC) vaccine will soon be unavailable in the UK immunisation schedule due to discontinuation by the manufacturer. An interim statement by the Joint Committee on Vaccination and Immunisation (JCVI) advises stopping MenC immunisation at 12 months of age when this occurs. We undertook an analysis of the public health impact of various potential meningococcal vaccination strategies in the UK in the absence of the Hib/MenC vaccine. A static population-cohort model was developed evaluating the burden of IMD (using 2005-2015 epidemiological data) and related health outcomes (e.g., cases, cases with long-term sequelae, deaths), which allows for the comparison of any two meningococcal immunisation strategies. We compared potential strategies that included different combinations of infant and/or toddler MenACWY immunisations with the anticipated future situation in which a 12-month MenC vaccine is not used, but the MenACWY vaccine is routinely given in adolescents. The most effective strategy is combining MenACWY immunisation at 2, 4, and 12 months of age with the incumbent adolescent MenACWY immunisation programme, resulting in the prevention of an additional 269 IMD cases and 13 fatalities over the modelling period; of these cases, 87 would be associated with long-term sequelae. Among the different vaccination strategies, it was observed that those with multiple doses and earlier doses provided the greatest protection. Our study provides evidence suggesting that the removal of the MenC toddler immunisation from the UK schedule would potentially increase the risk of unnecessary IMD cases and have a detrimental public health impact if not replaced by an alternate infant and/or toddler programme. This analysis supports that infant and toddler MenACWY immunisation can provide maximal protection while complementing both infant/toddler MenB and adolescent MenACWY immunisation programmes in the UK.