(NewsNation) — As China begins its most extensive coronavirus lockdown in two years Monday, pandemic-weary Americans are watching cautiously.

New York City offers a good example of how American are ready to move on. There are fewer masks, but more vaccinations, which experts say is the key to getting us past the so-called “stealth omicron.”

Where there used to be long lines at mobile testing sites, many are now closed or all but deserted.

States including Colorado and Minnesota are cutting back on testing.

According to the latest Centers for Disease Control and Prevention data, U.S. coronavirus cases are trending down and hospitalizations are way down.

“The virus is still circulating in the community,” said Dr. Dana Hawkinson, infectious disease physician with the University of Kansas Health System. “Right now, cases are still remaining low.”

But for many infectious disease experts, it’s not about what’s here. It’s about what may be coming.

French health authorities said Monday that the number of patients hospitalized for COVID-19 over the past 24 hours jumped by 467 to 21,073, the highest daily rise since Feb. 1.

“As we’ve seen over the past two years, a widespread outbreak like this in Europe has usually been followed by a similar surge here in the U.S.,” said Andrea Garcia, JD, MPH, director of science, medicine & public health at the American Medical Association.

“The most effective way we can prevent further variants of concern from arising is to vaccinate the world,” said Gavin Yamey, director of the Center for Policy Impact in Global Health at Duke Uninversity.

Where the West prefers vaccination, Chinese officials are sticking to a strategy called “zero-covid,” relying on lockdowns and mass testing to ward off a massive increase in cases.

The new measures being enforced in Shanghai aim to “curb the virus spread, protect people’s life and health, and achieve the dynamic zero-COVID target as soon as possible,” Shanghai’s COVID-19 prevention and control office stated in an announcement Sunday evening.

Reporting a new daily record for asymptomatic infections, Shanghai, China’s financial capital and largest city with 26 million people, said that it would lock down the city in two stages over a nine-day period.

The lockdown will be China’s most extensive since the central city of Wuhan was almost completely closed, shortly after the virus was first detected in late 2019.

Residents will be required to stay home and deliveries will be left at checkpoints to ensure there is no contact with the outside world. Offices and all businesses not considered essential will be closed and public transport suspended.

Panic buying was reported Sunday, with supermarket shelves cleared of food, beverages and household items. Additional barriers were being erected in neighborhoods Monday, with workers in hazmat suits staffing checkpoints.

Nationwide, 1,219 new confirmed cases of domestic infection were detected, the National Health Commission reported Monday.

“Only by doing dynamic zero-covid can we eliminate the hidden dangers of the epidemic,” said Zunyou Wu, China CDC’s chief expert of epidemiology.

It’s a very different strategy being employed in the U.S., where smartphone location data shows Americans decreased their movements, on average, by less than 1% during the stay-at-home mandates.

As the U.S. Food and Drug Administration is planning to authorize a fourth dose of the Pfizer and Moderna vaccines for adults older than 50 by the end of the week, U.S., officals are cautiously watching the cases in China and Europe.

The Associated Press and Reuters contributed to this repot.