Brazil's Serrana aims for COVID herd immunity first A Brazilian city of 45,000 has launched a major coronavirus vaccination drive. Health experts hope herd immunity could be achieved by May. Residents of Serrana are informed when it's their turn to receive a coronavirus vaccine jab Which cities will come to mind when we think about the coronavirus pandemic in a few years' time? Wuhan certainly, the Chinese city where everything likely began. Maybe Bergamo, New York, Guayaquil and Manaus — four cities hard hit by the outbreak. But what places will be remembered for containing COVID-19? That honor could go to Serrana, a small Brazilian town about 300 kilometers (185 miles) north of Sao Paulo. Despite being home to one of the country's largest sugar cane mills, Serrana is not a household name even in Brazil. But that could soon change.