Evolving epidemiology of poliovirus serotype 2 following withdrawal of the serotype 2 oral poliovirus vaccine.

Although there have been no cases of serotype 2 wild poliovirus for more than 20 years, transmission of serotype 2 vaccine-derived poliovirus (VDPV2) and associated paralytic cases in several continents represent a threat to eradication. The withdrawal of the serotype 2 component of oral poliovirus vaccine (OPV2) was implemented in April 2016 to stop VDPV2 emergence and secure eradication of all serotype 2 poliovirus. Globally, children born after this date have limited immunity to prevent transmission. Using a statistical model, we estimated the emergence date and source of VDPV2s detected between May 2016 and November 2019. Outbreak response campaigns with monovalent OPV2 are the only available method to induce immunity to prevent transmission. Yet our analysis shows that using monovalent OPV2 is generating more paralytic VDPV2 outbreaks with the potential for establishing endemic transmission. A novel OPV2, for which two candidates are currently in clinical trials, is urgently required, together with a contingency strategy if this vaccine does not materialize or perform as anticipated.

Investing in life saving vaccines to guarantee life of future generations in Africa.

The World Health Organization's Regional Offices for Africa and for the Eastern Mediterranean in conjunction with the African Union and the Government of Ethiopia hosted a ministerial conference on immunization in Africa from 24 to 25 February 2016 in Addis Ababa, Ethiopia under the theme "towards universal immunization coverage as a cornerstone for health and development in Africa". The conference brought together African leaders - including health and finance ministers, and parliamentarians thus creating a powerful platform for governments to demonstrate their commitment to advancing universal access to immunization on the continent in line with the Global Vaccine Action Plan. The event also brought together advocates, technical experts, policymakers, partner agencies, donors and journalists to examine how best to drive forward immunization across Africa, ensuring every child has access to the vaccines they need. Key points highlighted throughout conference were: universal access to immunization is at the forefront of enabling Africa to reach its full potential - by improving health, driving economic growth and empowering future generations; it is one of the most cost-effective solutions in global health, with clear benefits for health and development; and immunization brings economic benefits too, reducing health care costs and increasing productivity. At the close of the conference, 46 African countries signed a historic ministerial declaration on "Universal Access to Immunization as a Cornerstone for Health and Development in Africa" signaling fierce determination among African leaders to secure the health and prosperity of their societies through immunization.