In response to a rumour claiming that being bitten by mosquitoes twice would result in fatal dengue fever, the Health Bureau clarifies that after being infected with dengue fever, life-long immunity to that serotype of dengue virus will develop, but subsequent infections with other serotypes of dengue virus are more likely to result in severe dengue. In fact, not all mosquito bites can cause infection of dengue; therefore, fatal cases of dengue fever resulted by two mosquito bites do not exist in general.