A United States pharmaceutical company and an international DNA vaccine developer have been given the green light to start phase one of a Zika vaccine human trial.

In preclinical testing, the synthetic Zika DNA vaccine (GLS-5700) developed by Inovio Pharmaceuticals and GeneOne Life Science induced robust antibody and T cell responses in small and large animal models, demonstrating the product’s potential to prevent infection.

The human trial will be conducted in the coming weeks with 40 healthy subjects, the companies say, and will evaluate the safety of GLS-5700.