Transmission electron micrograph (TEM) of Zika virus. Credit: Cynthia Goldsmith/Centers for Disease Control and Prevention

Member nations have so far donated only 13 per cent of the money required to respond to the Zika virus outbreak in the first half of this year, the World Health Organization reported Monday.

The United Nations agency said it has received $2.3 million of the requested $17.7 million.

Overall, U.N. bodies, including WHO, had appealed for more than $56 million to fight the virus, which can cause serious neurological disorders. However, the funding received so far "has fallen far short of this request," WHO said.

The United Nations prioritized its spending plans anew in light of the lower level of donations "to ensure the limited available funding goes where it is most needed," WHO said without disclosing the new figure.

WHO has been coordinating international scientific work to study the virus, find ways to stop its spread, and to develop a vaccine.

In addition, WHO published a stream of material to inform the world about Zika, which is mainly spread by mosquitoes, but has also been passed on though sexual intercourse in a few known cases.

WHO has declared the current Zika outbreak - in mostly Latin American countries - a global health emergency because the virus can lead to malformed brains in newborns and paralysis in adults.

Most Zika patients experience only passing flulike symptoms.