Japan's Takeda Pharmaceutical Co. Ltd. said on Monday the U.S. Food and Drug Administration had granted "fast track" status to its vaccine for the mosquito-borne Zika virus, which erupted as a major public hazard in Brazil three years ago.

The drug, TAK-426, is currently being tested on 240 patients between the ages of 18 and 49 and is in early stages of development.

The virus might be responsible for an increase in birth defects in the United States and its territories, the U.S. Centers for Disease Control and Prevention said in a report last week.

The Zika outbreak was declared an international public health emergency by the World Health Organization in 2016 due to linkages found between the virus and severe birth defects.

The FDA's designation aims to facilitate the development and expedite the review process for certain drugs and vaccines for serious conditions with unmet medical need.