A vaccine effective against Zika virus is theoretically possible but may not be delivered anytime soon

Taylor-Robinson, Andrew W

The Aedes mosquito-transmitted viral disease of humans, Zika, was originally identified in 1947 and is named after the rainforest in Uganda, East Africa, where it was first isolated from rhesus macaques. 1 For close on 70 years, the prevalence of Zika infection was very low, such that prior to now it has attracted little interest apart from arbovirus and tropical medicine specialists. In the last several months, this scenario has changed dramatically, however, subsequent to a major Zika epidemic in over 35 countries in Latin America and the Caribbean. 2 This includes an estimated 1,400,000 clinical cases in Brazil, from where the outbreak arose in early 2015, 3 although questions regarding the accuracy of reporting have been raised. 4 Furthermore, the World Health 12 Taylor-Robinson Organization (WHO) predicts that by the end of this year up to 4 million people across the Americas may be infected with the Zika virus. 5 The impact on the vast majority of those people will be minimal, but particularly in infants the effect may be profoundly debilitating and long-lasting. Such is the extent of the issue, real and predicted, and the degree of concern that it has engendered globally, that on February 1, 2016 the International Health Regulations Emergency Committee of the WHO declared the Zika epidemic as "a public health emergency of international concern" and highlighted the importance of aggressive measures to reduce infection, especially of pregnant females and those of childbearing age. 6 Subsequently, the US Centers for Disease Control and Prevention moved Zika to level 1 activation, 7 the highest available state of response.