Washington: The first human trial to evaluate a candidate vaccine against coronavirus disease 2019 has begun in Seattle, US health officials said Monday.
"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 adding that the first participant received the investigational vaccine on Monday.
Meanwhile, US President Donald Trump has said the coronavirus pandemic that has killed thousands in countries across the world could be brought to a halt by July in the United States.
"So it seems to me that if we do a really good job... people are talking about July, August, something like that," Trump told reporters at the White House on Monday when asked how long the outbreak might last.
"So it could be right in that period of time where it, I say, it washes through."
Trump, who said the US "maybe" heading into a recession due to the virus, said he was asking Americans to restrict gatherings to groups of fewer than 10 when socializing outside or indoors.
Trump ruled out a national lockdown and said COVID-19 could send the economy into a recession while he announced new guidelines to battle the pandemic that has killed more than 65 Americans and pushed residents across 50 states into a near-total shutdown.
Trump's comments came on a day when the US stock market plunged 12 per cent on its worst day in more than 30 years and millions of Americans hunkered down at home, with the threat of job loss top of mind.
On Monday, the White House coronavirus task force urged older Americans to stay home, asked everyone to avoid groups of more than 10 for at least 15 days, and asked people to avoid going to restaurants and bars.
The guidelines revolve around six pillars: Listen to and follow the directions of your state and local authorities. If you feel sick, stay home. Do not go to work. Contact your medical provider. If your children are sick, keep them at home. Contact your medical provider. If someone in your household has tested positive for the Coronavirus, keep the entire household at home. If you are an older American, stay home and away from other people. If you are a person with a serious underlying health condition such as a significant heart or lung disease-stay home and away from other people.
White House coronavirus co-ordinator Deborah Birx said that if Americans follow these guidelines over the next 15 days, the US will see a clear difference in the trajectory of the pandemic.
"We will rally together as one nation and we will defeat the virus," Trump said. "We can turn the corner and turn it quickly. And then, we'll have a big celebration", Trump said.
Reacting to the new measures, doctors and nurses on the frontlines of America's fight against the coronavirus said that it's "going to be weeks if not months" for America emerge on the other side of the near lockdown situation.
The White House guidelines effectively transform how Americans will live and work and shop starting this week for at least a fortnight as the government scrambles to get its act together on expanding testing facilities.
Asked how the government defines "older Americans" since they are categorised among the high-risk cohort, Birx responded by saying that the difference between physical and physiological age is crucial to assess risk profile. She did not specify a number to describe "older" Americans.
The White House task force called on the country's millennial population, in particular, to follow the guidelines and help communicate key messages on social distancing across what is now America's largest population cohort.
Birx said millennials' ability to communicate successfully and intuitively can be a powerful force to stop the spread of the virus.
"They're a group that communicates successfully independent of picking up a phone. They know how to contact each other without being in large social gatherings. We're asking all of them to hold their gatherings to under 10 people, not just in bars and restaurants but in homes. We really want people to be separate at this time", Birx said.
In the US, a little less than 4,000 cases have been reported and more than 65 people have died from COVID-19.
"When you look at the projections, there's every chance that we could be Italy," Surgeon General Dr. Jerome Adams told Fox News, referring the new epicentre of the virus which began in China last December.
Two weeks ago, Italy had 1,700 cases of novel coronavirus and 34 deaths. Italy's death toll now is more than 1,800.
Anthony Fauci, America's top infectious diseases expert on the White House team, said Americans should not see the new guidelines as an "overreaction" and must take it "very seriously".
"When you're dealing with an emerging infectious diseases outbreak, you are always behind", he said.
"The best way to address it would be doing something that looks like it might be an overreaction but it's not an overreaction. It's a reaction that we feel is connected to what's going on in reality So take a look at the guidelines. Read them carefully. And we hope that the people of the United States will take them very seriously because they will fail if people don't adhere."
(With Agency Inputs)