^{Image credit: Louie Rosencrans/CDC from flickr}

An international team of researchers led by GSD Assistant Professor Dr Marco J Haenssgen have analysed the impact of mass vaccination campaigns, which are often used in global health efforts in low- and middle-income countries.

Their study, published in BMJ Global Health, is an evaluation of the polio eradication efforts in Nigeria from 2000 to 2017, which took the format of mass campaigns. Using the most detailed statistical analysis to date with exact dates of campaigns and child-level immunisation data, the researchers determined that the less-resourced a health system is the more common it is that standard healthcare services are sidelined in favour of the vaccination campaign, often on multiple occasions in a short space of time. The researchers estimate that the high intensity of polio eradication campaigns in the diverse healthcare landscape of Nigeria therefore left a total of 3.6 million children between 2000 and 2017 unvaccinated for the full immunisation schedule.

Based on these findings, the researchers warn that there must be a strategy to safeguard and strengthen health systems with fewer resources in low- and middle-income countries if such campaigns are used in the rollout of COVID-19 vaccines.

The research was carried out in collaboration with Johns Hopkins University researchers Assistant Professor Olakunle Alonge and Associate Professor Svea Closser.