NITA BHALLA and ANASTASIA MOLONEY AT a private hospital in Burundi's capital, emergency specialist Emmanuel Kubwayo is worried for the first time since the coronavirus started spreading around the world last year. Kubwayo initially shared the government's view that the small central African country did not need COVID-19 vaccines because it had so few cases. But as deaths and infections surge across Africa, he has changed his mind. Along with Eritrea, Tanzania and North Korea, Burundi is one of a handful of nations that have not started vaccinations, according to the World Health Organization (WHO), potentially threatening global efforts to…