Race to develop Zika virus vaccine and tests

Suspected links between the Zika virus and two neurological disorders, microcephaly in babies and Guillain-Barre syndrome, should be confirmed within weeks, the World Health Organization (WHO) said.

A sharp increase in birth defects in Brazil has triggered a global health emergency over the mosquito-borne virus and spurred a race to develop a vaccine and better diagnostic tests.

The WHO said US government scientists and an Indian biotechnology firm were currently frontrunners in the race to develop a vaccine and for the first time it advised pregnant women to consider delaying travel to zika-infected areas.

“It seems indeed that the link with zika [and microcephaly] is becoming more and more probable, so I think that we need a few more weeks and a few more studies to have this straight,” Marie-Paule Kieny, WHO assistant director-general for health systems and innovation, told a news briefing.

Studies of pregnant Latin American women who are confirmed as having had the zika virus and due to deliver their babies soon should yield evidence, Ms Kieny said, adding that data was also being collected from studies in French Polynesia and Cape Verde.

She said areas hit by the zika virus had also seen increased cases of the neurological disease Guillain-Barre, adding: “The direct causality has still to be demonstrated but the association in time and in location seems to be clear.”

Guillain-Barre syndrome, in which the body’s immune system attacks part of the nervous system, causes weakness in the legs, arms, and upper body and sometimes total paralysis.

The WHO reiterated it was not recommending travel or trade restrictions related to the zika virus, but added: “Women who are pregnant should discuss their travel plans with their health care provider and consider delaying travel to any area where locally acquired zika infection is occurring.”

Brazil, centre of the outbreak that has spread to more than 30 countries, is hosting the Olympics in August.

Ms Kieny said it would take at least 18 months to start large-scale clinical trials of candidate vaccines.

The US-based National Institutes of Health is working on a DNA-based vaccine that uses the same approach as one being developed for West Nile virus.