Brazilian doctor Oswaldo Cruz was a key player in Brazil’s history of conflict over public health measures. Battling yellow fever, he convinced public authorities to put in place sanitation measures to eliminate the insects’ breeding sites. His actions provoked a violent popular reaction but he won the fight in the end. Following the Vaccine Revolt of 1904, the 1908 outbreak of smallpox led the population to seek vaccination, which Cruz had advocated. As history seems to repeat itself, we will discuss the legacy of Oswaldo Cruz and how this inspires the work of the Oswaldo Cruz Foundation (FIOCRUZ) in fighting the COVID-19 pandemic under the current difficult circumstances in Brazil.