Warming temperatures could expose more than 1.3 billion new people to Zika virus risk by 2050

In the aftermath of the 2015 pandemic of Zika virus, concerns over links between climate change and emerging arboviruses have become more pressing. Given the potential that much of the world might remain at risk from the virus, we use a model of thermal bounds on Zika virus (ZIKV) transmission to project climate change impacts on transmission suitability risk by mid-century (a generation into the future). In the worst-case scenario, over 1.3 billion new people could face suitable transmission temperatures for ZIKV by 2050. Given these suitability risk projections, we suggest an increased priority on research establishing the immune history of vulnerable populations, modeling when and where the next ZIKV outbreak might occur, evaluating the efficacy of conventional and novel intervention measures, and increasing surveillance efforts to prevent further expansion of ZIKV.Author SummaryFirst discovered in Uganda in the 1950s, Zika virus (ZIKV) is a new threat to global health security. The virus is spread primarily by female Aedes mosquitoes, with occasional sexual transmission in humans, and can cause Zika congenital syndrome (which includes fetal abnormalities like microcephaly) when women are infected during pregnancy. Our study is the first to quantify how many people may be exposed to temperatures suitable for ZIKV transmission in a changing climate. In the worst-case scenario, by 2050, climate change could expose more than 1.3 billion people worldwide to temperatures suitable for transmission - for the first time. The next generation will face substantially increased ZIKV transmission temperature suitability in North America and Europe, where naïve populations might be particularly vulnerable. Mitigating climate change even to moderate emissions scenarios could significantly reduce global expansion of climates suitable for ZIKV transmission, potentially protecting around 200 million people.