Austrian biotech company Themis Bioscience said on Tuesday it had started a clinical trial of an experimental Zika vaccine in healthy volunteers, opening up another front in the race to prevent the spread of the mosquito-borne disease.
Themis's product, which is based on measles immunization technology, is the first vaccine containing attenuated, or weakened, live virus to reach the human testing phase.
Multiple research groups, biotech firms and pharmaceutical companies are working on different Zika vaccine approaches, but only a few have so far advanced into clinical trials.
U.S.-based Inovio Pharmaceuticals announced in December that its experimental vaccine had induced robust immune responses in human volunteers, while U.S. government scientists are beginning the second phase of testing another vaccine.
Among big drugmakers, France's Sanofi has the most advanced Zika vaccine development program.
Themis, which is unlisted, said its Phase I clinical trial would involve 48 healthy volunteers and be conducted at the Medical University of Vienna.
Zika typically causes mild symptoms, but when the virus infects a pregnant women it can be passed to the foetus, causing a variety of birth defects including microcephaly, in which the baby's head is abnormally small.
(Reporting by Ben Hirschler; editing by Jason Neely)