A new study that analysed the coronavirus outbreak in Brazil has found a link between the spread of the virus and past outbreaks of dengue fever that suggests exposure to the mosquito-transmitted illness may provide some level of immunity against Covid-19. The study, which hasn’t yet been published, was led by Miguel Nicolelis, a professor at Duke University. It compared the geographic distribution of Covid cases with the spread of dengue in 2019 and 2020. Places with lower Covid infection rates and slower case growth were locations that had suffered intense dengue outbreaks this year or last, Nicolelis found. He said further studies are needed to prove the connection. The team found a similar relationship between dengue outbreaks and a slower spread of Covid in other parts of Latin America, as well as Asia and islands in Pacific and Indian Oceans. reuters