Effectiveness of pneumococcal vaccination campaigns in humanitarian settings: a modelling study

A large and increasing number of people are forcibly displaced worldwide because of war, food insecurity, and other crises. Streptococcus pneumoniae (the pneumococcus) likely causes a substantial health burden in crisis-affected populations, but pneumococcal vaccines (PCVs) are rarely used in humanitarian responses.

‍This study evaluated the potential impact of logistically feasible PCV campaigns in such settings.

It found a single-dose PCV campaign with high vaccine coverage in children <5y or older can partially control vaccine-serotypes for up to three years, preventing 27% of severe pneumococcal disease when vaccinating <5y olds and 38%  when vaccinating <15y olds. Expanded age eligibility is needed for comparable protection in settings with increased migration or more interaction with unvaccinated host populations. A campaign vaccinating <5y olds is the most efficient use of PCV with 108 vaccines needed to prevent one case of severe pneumococcal disease. Implementing such campaigns in displaced populations worldwide would require about 40 million doses in the next five years.

In summary, single-dose PCV mass-vaccination campaigns offer crisis-affected populations an effective, pragmatic immunisation strategy.

PCV mass vaccination strategies have previously been shown to be cost-effective in crisis settings, but this study adds to the evidence base as the first (known to the study team) to directly compare the effect and efficiency of different age eligibility and dosing regimens in crisis-affected populations.