A medic puts a sign on the little finger of a child after he receives an anti-cholera vaccine against cholera in Sanaa, Yemen, on April 24, 2019. Yemeni Health Ministry in collaboration with WHO and UNICEF launched a 6-day home-to-home emergency immunization campaign against cholera in three most seriously affected districts in Sanaa with an aim to target all people from age of one year and above except pregnant women. (Xinhua/Mohammed Mohammed)