Zika Virus Disease: Progress and Prospects

Zika virus (ZIKV) is a mosquito borne flavivirus that exhibits wide range of transmission routes including mosquito, transplacental, sexual contact, blood transfusion and organ transplantation. ZIKV is highly neurotropic which infects central nervous system (CNS) in adult and developing brain. As of 2021, at least 86 countries and territories have been reported with autochthonous transmission of ZIKV. Preexisting flavivirus specific sero-cross reactivity antibodies may results in antibody dependent enhancement (ADE) of ZIKV infection with significant higher viral load and severe disease outcomes. However, the mechanism of ADE has not been completely understood. Upon ZIKV infection, innate immune system, humoral immune response and cellular mediated response get activated. Even though, the virus has developed several immune escape strategies for successful infection. Currently there is no specific treatment available for ZIKV infection and the treatment relies on the symptomatic relief of the patients. However, several of the drug candidates have been discovered and are currently in the clinical trials. Molecules have been targeted against potential viral proteins including entry inhibitors, protease inhibitors and replication inhibitors. In spite of progress made in this area, the absence of clinically approved drug or vaccine increases the chances of recurrent outbreak in endemic regions and therefore needs utmost attention in this issue.