Zika link to microcephaly and Guillain-Barre syndrome expected to be confirmed ‘within weeks’

Passengers arriving at South Korea's Incheon International Airport, west of Seoul, walk past heat detectors set up at check points as the country strengthens monitoring against the Zika virus. EPA

GENEVA // The World Health Organization (WHO) expects suspected links between the Zika virus and two neurological disorders, microcephaly in babies and Guillain-Barre syndrome, to be confirmed within weeks, a top official said on Friday.

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.

“We have a few more weeks to be sure to demonstrate causality, but the link between Zika and Guillain-Barre is highly probable,” said Marie-Paule Kieny, WHO assistant director-general for health systems and innovation.

WHO has said that Zika’s link with microcephaly, meanwhile, is “strongly suspected”.

While most people infected with Zika have only mild symptoms, rising anxiety about the virus is driven by its strongly suspected link to the two more serious conditions.

Microcephaly can cause babies to be born with abnormally small heads and brains, while Guillain-Barre can cause paralysis or even death.

Ms Kieny said US government scientists and an Indian biotechnology company were currently front-runners in vaccine development, although it would take at least 18 months to start large-scale clinical trials of candidate shots.

“Two vaccine candidates seem to be more advanced: a DNA vaccine from the US National Institutes for Health (NIH) and an inactivated product from Bharat Biotech in India,” she said.

The NIH is working on a DNA-based vaccine that uses the same approach as one being developed for West Nile virus. India’s Bharat said last week that its experimental vaccine would start preclinical trials in animals imminently.

Overall, around 15 groups are working on Zika vaccines, including France’s Sanofi, as well as researchers in Brazil, who announced a new partnership with the University of Texas on Thursday.

The road to developing a preventive shot against the disease is strewn with hurdles, however, not least because the group viewed as most at risk are pregnant women.

Improved diagnostic tests are also viewed as critical to fighting the disease, which is now sweeping through the Americas, and Ms Kieny said new test kits were being rapidly developed and could be available in weeks.

Researchers in Brazil are scrambling to determine whether Zika has caused a major rise in microcephaly, with more than 4,000 suspected cases of the condition reported to date. Brazil has confirmed more than 400 of those cases as microcephaly and has identified the presence of Zika in 17 babies, but a link has yet to be proven.

Still, many scientists are convinced that the link is real and new evidence of Zika in the brain of an aborted foetus, reported on Wednesday, has added to the case.

On Friday, WHO said in new advice that women who are pregnant should consider putting off travel to areas infected with the Zika virus as a precautionary measure.

“Based on the latest evidence that Zika virus infection during pregnancy may be linked to microcephaly in newborns, WHO is issuing further precautionary travel advice to women who are pregnant and their sexual partners,” it said.

“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.”

Governments across Latin America have launched a range of programmes in an effort to contain the spread of Zika, including measures to attack mosquito populations and curb breeding of the insect.

In Brazil, some 220,000 soldiers are set to go door-to-door on Saturday to hand out leaflets advising of a massive insecticide spraying campaign.

Ms Kieny said on Friday that WHO’s “relatively poor knowledge” of Zika had affected research and development (R&D) options to contain the virus and stop its spread.

But, she added, the emergency R&D response systems set up following the Ebola epidemic in West Africa was proving useful and the response to Zika was “proceeding very quickly”.

* Reuters, Agence France-Presse