GENEVA/CHICAGO • The World Health Organisation (WHO) has declared that Zika no longer constitutes an international emergency, though it stressed a need for a long-term effort to address the virus linked to birth defects and neurological complications.
Officials on WHO's Emergency Committee said the virus, which has been found in 60 countries since the outbreak was identified last year in Brazil, still constitutes a global public health threat.
They warned that it will continue to spread where mosquitoes that carry the virus are present.
Removing the international emergency designation will put Zika in a class with other diseases, such as dengue, that pose serious risks and require continued research, including efforts to develop effective vaccines.
But some public health experts worried that losing the "international emergency" label could slow research into the virus, which continues to cause infections in the United States and elsewhere.
WHO in February declared Zika a public health emergency of international concern - a designation under international law that compels countries to report outbreaks.
The moved was part of an effort to determine if Zika was linked to reports in Brazil of the severe birth defect microcephaly and the neurological disorder Guillain-Barre Syndrome.
Traditionally, Zika had only been thought to cause mild symptoms.
That goal has been met, said Dr David Heymann, chair of the Zika Emergency Committee and a professor of infectious disease at the London School of Hygiene and Tropical Medicine, to reporters .
Because research has now shown that Zika and microcephaly are linked, he said that "the committee felt that what is best now is a very robust technical response to the virus, and that would require work within WHO".
WHO maintained its recommendations, including that people exposed to the Zika virus should take preventive measures for six months to avoid sexual transmission.
Pregnant women should also avoid travelling to areas with local transmission of Zika.
Some experts were concerned that the WHO decision might result in less support for research of the virus.
"Although Zika's spread has waned, it still holds the potential for an explosive epidemic.
"If it were to re-emerge in the Americas or jump to another part of the world, it would significantly threaten a new generation of children born with disabilities such as microcephaly," said Dr Lawrence Gostin, a global health law expert from Georgetown University.
Dr Peter Salama, executive director of WHO's Health Emergencies Programme, insisted that WHO is "not downgrading the importance of Zika".
By framing Zika as a longer programme of work, it is sending the message that Zika is here to stay and that likewise, "WHO's response is here to stay in a very robust manner".