WASHINGTON, May 3 (Xinhua) -- The lockdown programs in Wuhan and other parts of China have proven successful and helpful for other countries for the effective control and prevention of the coronavirus disease (COVID-19), a world-renowned expert has said.

"I have called them (lockdown programs) before the largest public health experiment in the history of humankind. And you know, I think the experiment was a success, because it clearly, now we have evidence, reduced very much the transmission of this highly contagious virus," William Schaffner, an influential infectious disease specialist, told Xinhua in a recent interview.

Schaffner is professor of Preventive Medicine in the Department of Health Policy as well as Professor of Medicine in the Division of Infectious Diseases at the Vanderbilt University School of Medicine, Nashville, Tennessee.

"And so we're trying to model, what we're doing along the lines of what happened in China. We're not as severe, but the principles are the same and going forward, other countries are also learning from that part of the China experience," said Schaffner, referring to the stay-at-home orders and social distancing measures taken by U.S. states to curb the spread of the COVID-19.

The public health expert cautioned Americans to exercise proper social distancing practices as a number of states began reopening their economies with more set to lift restrictions in the coming week.

"It's no longer a matter of whether we're going to do it, but when and how. So some people have gone first. Perhaps they're a little bit early. But the trick is to balance the medical side with the economic, social, and cultural side," Schaffner said.

"And that's going to be very tricky. If we open up, we have to maintain social distancing. The use of masks, for example, six feet, good hand hygiene, taking temperatures before you go into a store. All of those things will be very important and still, staying home, not going out so much, " he said.

"I think we must still obey the rules and the recommendations and be conservative, not be so eager to get out because we don't want suddenly more coronavirus and then a second wave, right?" he said.

On April 8, China lifted outbound travel restrictions on Wuhan, the city hardest hit by the coronavirus outbreak, ending a lockdown that sealed off around 10 million people from the rest of the world for 76 days.

Over 1.4 million infections and 56,000 deaths might have been avoided as a result of the national and provincial public health measures imposed in late January in China, according to a new study led by Xi Chen, a professor at Yale School of Public Health and published in the Journal of Population Economics on April 9.

"In the face of a previously unknown virus, China has rolled out perhaps the most ambitious, agile and aggressive disease containment effort in history," said a report of the WHO-China Joint Mission on COVID-19 released in late February.