The World Health Organization on Friday declared that Zika no longer constitutes an international emergency, but it stressed a need for a long-term effort to address the virus, which has been linked to birth defects and neurological complications.

Because research has now shown that Zika and microcephaly are linked, "the committee felt that what is best now is a very robust technical response to the virus, and that would require work within WHO," he said.

The U.N. health agency maintained recommendations including that people exposed to the Zika virus should take preventive measures for six months to avoid sexual transmission.