LONDON — Scientists are “weeks, not years” from developing a test for the fast-spreading Zika virus, but large-scale clinical trials for a potential vaccine are at least 18 months away, the World Health Organization announced Friday.
The WHO declared Zika a global public health emergency on Feb. 1, only the fourth time it had raised such an alert. The Zika virus — a mosquito-transmitted infection related to dengue, yellow fever and West Nile virus — has spread through Latin America. It was first detected in Brazil in May, and as many as 4 million people worldwide could be infected by year’s end, the health organization has said.
The main public health concern is a suspected link between the virus and two neurological disorders: microcephaly, which is associated with unusually small heads and, often, brain damage in infants; and Guillain-Barré syndrome, in which a person’s immune system attacks part of the nervous system, leaving some almost completely paralyzed for weeks.
Scientists are close to confirming those links, Dr. Marie-Paule Kieny, the WHO assistant director general for health systems and innovation, said at a news conference in Geneva.
There is no reliable test yet for Zika. Ten companies are poised to provide tests that attempt either to use a molecular technique to detect the virus’ presence in blood or to confirm Zika infection by measuring the levels of antibodies in a patient who has been exposed to the virus. Another 10 companies are trying to develop tests using similar approaches.
“It is important to point out, however, that none of these tests have been independently validated and none have regulatory approval,” Kieny said. She added, however, that “we are talking weeks, not years,” for the first commercial and independently validated tests to become available.
There is no vaccine for Zika, although a race to develop one is underway. Kieny pointed to two particularly promising efforts: one by the National Institute of Allergy and Infectious Diseases, in Bethesda, Maryland, and the other by Bharat Biotech, a pharmaceutical company in Hyderabad, India.
“In spite of this encouraging landscape, vaccines are at least 18 months away from large-scale trials,” she said.