American biotechnology firm Moderna on Sunday said that the United States government will provide an additional $472 million (Rs 3,533 crore) for its coronavirus vaccine development programme. The US government had earlier announced $483 million (Rs 3,616 crore) to the company to expedite vaccine development, which now brings the total investment in the programme close to $1 billion (Rs 7,485 crore).

Moderna has received the additional support from the government as it has expanded the third phase of the clinical trial of its vaccine candidate to include 30,000 volunteers. The third phase of the clinical trial will begin on Monday. In its initial smaller trial, the vaccine had been successful in producing antibodies in 45 participants.

Moderna was the first firm to start human testing of a coronavirus vaccine in March. The company had unveiled a plan to conduct the trials at 87 study locations across the US. The Moderna vaccine uses ribonucleic acid or RNA, which is a chemical messenger that contains instructions for making proteins to fight the coronavirus infection.

Researchers across the world are racing to develop a coronavirus vaccine. Last week, a coronavirus vaccine being produced by scientists at the University of Oxford in the United Kingdom was found to be safe, and produced an immune response in early-stage clinical trials in healthy volunteers. The vaccine, called AZD1222, did not cause any serious side effects and elicited antibody and T-cell immune responses.

In India, the All India Institute of Medical Sciences, Delhi, began human trials of indigenous coronavirus vaccine Covaxin on Friday. India’s second vaccine candidate also entered the human trials stage earlier this month.

The coronavirus has infected more than 1.6 crore people globally and claimed over 6.48 lakh lives, according to the Johns Hopkins University. In US, more than 42 lakh people have been infected while over 1.46 lakh have died.