Created in a partnership between drug companies Inovio Pharmaceuticals and GeneOne Life Science, the vaccine, GLS-5700, showed promise when tested in small and large animals.

The vaccine will be tested on approximately 40 patients and results will be announced later this year, the companies said.

Currently, there is no vaccine for Zika, a virus that was first detected in Africa but has spread rapidly through the Americas.

Related to the viruses that cause yellow fever, dengue, and West Nile disease, Zika is spread through mosquito bites or sexual activity. Although symptoms are relatively mild, health officials are alarmed by the disease because it is linked to devastating birth defects.

“We are proud to have attained the approval to initiate the first Zika vaccine study in human volunteers,” Inovio CEO J. Joseph Kim said in a statement. “As of May 2016, 58 countries and territories reported continuing mosquito-borne transmission of the Zika virus; the incidences of viral infection and medical conditions caused by the virus are expanding, not contracting. We plan to dose our first subjects in the next weeks and expect to report phase I interim results later this year.”

Inovio, based in Pennsylvania, and GeneOne Life Science, based in South Korea, have collaborated before on experimental vaccines for Ebola and Middle East respiratory syndrome, or MERS.

Zika has been confirmed in nearly 40 countries in South America, North America and the Caribbean.

The Centers for Disease Control and Prevention announced last week that it believes thousands of pregnant women could be infected by the virus in the coming months.

Scientists have also questioned whether the Summer Olympic Games in Rio de Janeiro should be moved or postponed due to the virus.

Anadolu Agency