"The open-label trial will enroll 45 healthy adult volunteers ages 18 to 55 years over approximately 6 weeks," the US National Institutes of Health (NIH) said in a statement.
"The first participant received the investigational vaccine today."
According to a report by the Associated Press (AP), scientists at the Kaiser Permanente Washington Research Institute in Seattle begin an 'anxiously awaited first-stage study of a potential COVID-19 vaccine developed in record time'.
Forty-three-year-old Jennifer Haller of Seattle, an operations manager at a tech company, received the injection inside an exam room.
Haller, the mother of two teenagers, termed it an "amazing opportunity" for her to "do something".
The said 'vaccine', codenamed mRNA-1273, was developed by the National Institutes of Health (NIH) and Massachusetts-based biotechnology company Moderna Inc.
More than 1,50,000 people have been infected worldwide by the virus which originated in China last December and has claimed the lives of over 7000 people.
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"We are team coronavirus now. Everyone wants to do what they can in this emergency," Kaiser Permanente study leader Dr Lisa Jackson was quoted as saying on the eve of the experiment.
Jackson said that from not even knowing that coronavirus was out there to have any vaccine in testing in about two months is 'unprecedented'. She, although, said that it is not at this stage where it would be "possible or prudent" to give it to the general population.
The tests came amid worldwide attempts to develop the vaccine for the deadly virus.
However, these vaccines are unlikely to be available for widespread use anytime for 12 to 18 months, said Dr Anthony Fauci of the NIH.
Finding a vaccine "is an urgent public health priority," Dr Fauci was quoted as saying.
According to the AP report, most of the vaccine research underway targets a protein aptly named "spike" that studs the surface of the new coronavirus and lets it invade human cells.
Trump says 'promising early results':
The President of US said that he is pleased to report that a vaccine candidate has begun the phase-1 clinical trial.
"I am pleased to report that a vaccine candidate has begun the phase-1 clinical trial. It's one of the fastest vaccine development launches in history. We are also racing to develop anti-viral therapies and other treatments. We have some promising early results," he said.
According to CNN, Trump said as of Monday there are no plans for a nationwide quarantine or curfew.
(with inputs from agencies)