1. United Nations. Sustainable Development Goals. Available at: https://sdgs.un.org/goals [accessed 2020 August 15].
2. Gavi, the Vaccine Alliance. Available at: https://www.gavi.org [accessed 2020 August 15].
3. Millennium Challenge Corporation. Available at: https://www.mcc.gov/ [accessed 2020 August 15].
4. Protecting the World’s Children: Immunization Policies and Practices,2013
5. World Health Organization. Decade of Vaccines --- Global Vaccine Action Plan 2011–2020. Available at: https://www.who.int/immunization/global_vaccine_action_plan/DoV_GVAP_2012_2020 [accessed 2020 August 15].