Zika virus outbreak began in Brazil in 2015 and was linked to microcephaly in newborns. In response, Brazil approved releasing genetically modified mosquitoes. The CDC and WHO activated emergency response teams to study Zika's transmission and link to microcephaly, develop tests, provide guidance, and support Brazil. Brazil launched a national microcephaly response plan involving vector control, healthcare, and research. The WHO provided information and guidance, produced documents on topics like psychosocial support, and received $56 million in funding from 23 partners for its strategic response. Brazil mobilized 220,000 soldiers to educate people on reducing mosquito breeding grounds.