Nurses look at instructions regarding vaccine protocol on a mobile phone after being administered the COVID-19 vaccine at the District Hospital in Ukhrul, in the northeastern Indian state of Manipur, Saturday, Jan. 16, 2021. India started inoculating health workers Saturday in what is likely the world's largest COVID-19 vaccination campaign, joining the ranks of wealthier nations where the effort is already well underway. (AP Photo/Yirmiyan Arthur)