The World Health Organisation (WHO) has said it could take up to a year before a vaccine for coronavirus is available.
A number of vaccine trials have started in various parts of the world, especially in China.
The WHO itself has began 'solidarity trials' - which means a range of countries coming together to test four different drug combinations.
One clinical vaccine trial is also underway in the United States at Kaiser Permanente Washington Health Research Institute (KPWHRI) in Seattle.
The US National Institute of Allergy and Infectious Diseases (NIAID) is funding the trial.
It will enroll 45 healthy adult volunteers ages 18 to 55 years over approximately six weeks.
The first participant received the investigational vaccine on March 16th.
The study is evaluating different doses of the experimental vaccine for safety, and its ability to induce an immune response in participants.
However this is the first of multiple steps in the clinical trial process.
The vaccine, called mRNA-1273, was developed at the biotechnology company Moderna in Massachusetts.
"Finding a safe and effective vaccine to prevent infection with SARS-CoV-2 is an urgent public health priority,” said NIAID director Anthony Fauci.
"This phase one study, launched in record speed, is an important first step toward achieving that goal."
Currently, there is no approved vaccine to prevent COVID-19 infection.
Dr Michael Ryan is head of the WHO's Emergency Health Programme.
Speaking to the BBC, he said people need to continue their efforts to stop the spread.
"The issue with testing is we need to find suspect cases, we need to find people who have the virus and we need to isolate those patients as quickly as possible.
"The physical distancing measures that are in place and the lock downs - separate everybody from everybody else.
"But what we really need to focus on is finding those who are sick, those who have the virus and isolate them, find their contacts and isolate them.
"The danger with the lock downs and all the physical distancing - and people are feeling this now - that's really putting pressure on the economy, it's putting pressure on the social system.
"If we don't put in place the strong public health measures now, when those restrictions are lifted, the danger is the disease will jump back up".
"In China, and in Singapore, in Korea they really focused on having that comprehensive strategy.
"So when they got the flames of the fire were pushed down - through physical distancing or through lock downs - they then went after the virus.
"And we need to actively search for cases of the virus and we need to test every single suspect case.
"We don't need to test everybody, we need to focus on testing those who may have the virus".
On a vaccine, Dr Ryan said: "We are talking a least a year, but that doesn't mean that we're helpless.
"We can do a lot to stop this disease right now, and we can save a lot of lives right now.
"We will work hard on the vaccines, the vaccines will come, but we need to get down and do what we need to do now".