, GENEVA, Switzerland, Feb 12 – Large-scale trials for Zika virus vaccines are at least 18 months away, while establishing a possible link between the virus and two more harmful conditions will likely only take weeks, the World Health Organization said Friday.
An estimated 15 companies or groups have begun work on a vaccine for the previously obscure virus which has now become a global concern, WHO’s deputy director for health systems and innovation Marie-Paule Kieny told journalists.
There are currently two candidates which appear most promising, including one vaccine being developed by the US National Institutes of Health and another from India-based Bharat biotech, Kieny said.
“In spite of this encouraging landscape, vaccines are at least 18 months away from large-scale trials,” she added.
Meanwhile, Kieny said it would take an estimated “few weeks” to establish whether Zika causes microcephaly and the severe neurological disorder Guillain-Barre syndrome.
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.
WHO has said Zika’s link with microcephaly was “strongly suspected,” while Kieny told journalists Friday that the causal relationship with Guillain-Barre was “highly probable.”
“I think the evidence is building on the causal link,” she added, explaining that an ongoing trial among pregnant woman in Colombia was expected to yield new evidence soon.