National routine adult immunisation programmes among World Health Organization Member States: an assessment of health systems to deploy COVID-19 vaccines
Williams, Sarah R and Driscoll, Amanda J and LeBuhn, Hanna M and Chen, Wilbur H and Neuzil, Kathleen M and Ortiz, Justin R, Eurosurveillance, 26, 2001195 (2021), https://doi.org/10.2807/1560-7917.ES.2021.26.17.2001195