US President Donald Trump on Monday boasted about the early trial results of COVID-19 vaccine developed by US-based biotechnology giant Moderna, saying “these great discoveries” happened on his watch.

"Another Vaccine just announced. This time by Moderna, 95% effective. For those great "historians", please remember that these great discoveries, which will end the China Plague, all took place on my watch!" Trump tweeted.

President-elect Joe Biden said the news is “further reason to feel hopeful" but at the same time he urged Americans to continue to practice social-distancing.

"Today's news of a second vaccine is further reason to feel hopeful. What was true with the first vaccine remains true with the second: we are still months away. Until then, Americans need to continue to practice social-distancing and mask-wearing to get the virus under control,” Biden said.

"Once again, I congratulate the brilliant women and men who produced this breakthrough and have brought us one step closer to beating this virus. I am also thankful for the frontline workers who are still confronting the virus around the clock,” tweeted the President-elect.

Indian-American Dr Vivek Murthy, who is co-chair of the Biden Transition COVID-19 Advisory, described this as a promising news.

"Promising News: early data today from a second #covid19 vaccine shows 94.5% effectiveness. This is very encouraging. FDA evaluation still needed and wide availability is months away, so keep masking, distancing, and hand washing to Stop the Spread,” he said.

Moderna announced on Monday that its COVID-19 vaccine has shown to be 94.5 per cent effective in preventing the deadly disease, bringing a glimmer of hope to a world ravaged by the pandemic.

The National Institute of Health in a statement said that interim review of data suggests that the Moderna vaccine is safe and effective at preventing symptomatic COVID-19 in adults.

So far the coronavirus has infected more than 54 million people around the world even as governments implemented strict lockdowns and restrictions to slow the spread of the virus that originated in the Chinese city of Wuhan.

A second wave of infections is threatening to derail economies and impact lives again as countries have gradually begun to ease restrictions and open up.