SWAT THAT VIRUS Hospital patients recover from dengue virus infection under bed nets in Asunción, Paraguay, in 2012. The following year, the country hit a high of more than 144,500 reported cases. Vaccines may be the best means of defense against moquito-borne viruses like dengue, Zika and chikungunya.
NORBERTO DUARTE/AFP/GETTY IMAGES
Humans can’t easily protect themselves from the most dangerous species on Earth.