Mosquito‑borne illnesses are spread to humans through the bite of an infected mosquito. Mosquitoes are small insects that breed in still or very slow‑moving water and feed on the blood of animals or humans, often causing itchy, irritating bites. While mosquito bites are commonly considered a nuisance, some mosquito species can transmit serious diseases. Worldwide, mosquito‑borne illnesses include chikungunya, dengue, Japanese encephalitis, malaria, Oropouche virus disease, West Nile virus, yellow fever, and Zika.

An effective way to prevent and protect against some mosquito‑borne illnesses is vaccination. Unfortunately, vaccines are not available for all mosquito‑borne diseases. Currently, there are no approved vaccines in Canada for dengue, malaria, Oropouche virus disease, West Nile virus, or Zika. However, vaccines are available for certain mosquito‑borne illnesses, including chikungunya, Japanese encephalitis, and yellow fever.