Impact of COVID-19 on routine immunization in Oyo State, Nigeria: trend analysis of immunization data in the pre- and post-index case period; 2019-2020.

Introduction: the response to COVID-19 pandemic has posed new obstacles to the fragile health system, most especially in the area of vaccination across much of Africa. As the response to the pandemic intensifies through the application of non-pharmacologic interventions as well as enforcement of the lockdowns across African cities, there is a significant risk that more children will miss out on life-saving vaccines that can prevent childhood killer diseases. This study was therefore conducted to look at the impact of the COVID-19 pandemic on routine immunization in Oyo State, Nigeria.