Small bottles labeled with a "Vaccine COVID-19" sticker and a medical syringe are seen in this illustration taken taken April 10, 2020.

 Zydus has received approval from Indian regulators to begin human studies for its COVID-19 vaccine contender, the drugmaker said on Friday, as the novel coronavirus infections continue to surge in the world’s fourth worst-hit nation.

The potential vaccine showed a “strong immune response” in animal studies, and the antibodies produced were able to completely neutralize the wild type virus, Zydus, part of Cadila Healthcare Ltd, said in a statement to Indian stock exchanges.

 approval for Zydus comes days after privately held Bharat Biotech got a similar green light for human studies for its vaccine candidate.

Zydus will begin human trials this month in over 1,000 subjects in multiple sites in India, it said. The company also plans to ramp up its production capacity for the vaccine contender to serve Indian and global demand, it added.

 There were no safety concerns for the vaccine candidate in repeat dose toxicology studies, Zydus said. In rabbits, up to three times the intended human dose was found to be safe, well tolerated and immunogenic.

No vaccine has yet been approved for commercial use against COVID-19, but more than a dozen from over 100 candidates globally are currently being tested in humans, and some have shown potential in early-stage trials.

 The number of coronavirus infections in India surpassed 600,000 on Thursday, resulting in 17,834 deaths as authorities battled to contain the pandemic while easing lockdown rules. Only the United States, Brazil and Russia have reported more cases than India.