(CNN) — Covid-19 precautions need to stay consistent — whether or not the numbers are coming down — because the more Americans move around the more the virus does too, a health expert said.

When case numbers start to come down, people tend to interact more, and more movement predicts how the virus will spread, said Dr. Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington.

Though cases have risen to more than 4.9 million and coronavirus deaths have surpassed 161,000, former hotspots like New York are seeing positive changes. But health experts have predicted the national death toll will get worse through the year, and many have called for a stronger national leadership against the virus.

In list ranking countries response to the pandemic assessed by Foreign Policy Magazine, the United States ranks near the bottom.

“If you look at the mobility data collected from cell phones in many parts of the country, we’re almost back to pre-Covid levels of mobility, so we’re just not being as cautious as other people are in other countries,” Murray told CNN’s Wolf Blitzer on Friday.

Precautions can bring and keep the numbers down while the nation waits on a vaccine, US Surgeon General Dr. Jerome Adams said in a news briefing Friday. All it takes is what he calls his “Three W’s.”

“Number one, wash your hands. Number two, watch your distance — meaning stay at least six feet from others and avoid crowded places. And number three, wear a face mask,” Adams said.

Rethinking testing

One important factor to reopening the US while maintaining safety is rethinking the national strategy on testing for the virus, said Dr. Rajiv Shah, president of the Rockefeller Foundation and former USAID administrator.

Currently, only symptomatic people are frequently tested, meaning 40% to 50% of all spreaders, those who don’t show symptoms, aren’t being tested and told they may be contagious, he said.

“You have to know that as soon as possible, and then limit transmission from that node of contagion,” he said during an Aspen Ideas webinar on Friday. “That’s the whole ball game.”

But even testing primarily symptomatic people been impacted by backlog, many states report.

The Virginia Department of Health reported a sharp increase of cases on Friday, but that increase came from a technical issue and a backlog from the two days prior, according to a statement.

And Miami-Dade County, the hotspot for cases in Florida, continues to struggle with a lag in testing results, according to state data obtained by CNN.

One day in the past week, testing labs reported that 19.2% of test results took more than seven days to deliver. On a different day, 45% of test results took between four and seven days.

Precautions matter for children, too

As schools reopen for the new school year, researchers are learning more about how the virus spreads among children.

A new report from the Centers for Disease Control and Prevention supports the early belief that most coronavirus cases in children appear to be either asymptomatic or mild. But, the report said, when children are hospitalized, they need the intensive care unit as often as adults do.

To slow the pandemic, the CDC said children should be encouraged to wash their hands often, keep a good physical distance away from others, and if they are 2 years of age or older, they should wear a mask when they are around people outside of their family members.

One rare but serious complication children can develop from a coronavirus infection is known as multisystem inflammatory syndrome, or MIS-C, and at least 570 cases have been reported, the CDC said.

As the pandemic continues, health care providers should be on the lookout for the syndrome that most commonly causes abdominal pain, vomiting and a skin rash.

More than 74% of the cases were among Hispanic and Black children, the CDC said.

Pandemic highlights racial disparities

For communities of color, Covid-19 has been a “double whammy” that shows the work the US needs to do to correct disparities in health and health care, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said on Friday.

For example, Black Americans are more likely to have jobs that are considered essential, Fauci said, which leads to a much greater risk of being infected.

“Then there’s the other thing that is really the chronic and decades-old dilemma of the social determinants of health, which is why African Americans have a higher degree of diabetes, of hypertension, of obesity, of heart disease, of chronic lung disease, of kidney disease,” Fauci said. “That does not need to be. But to get corrected, you have to make a decades-long commitment to change that.”

Part of that commitment has to include making resources like immediate testing and results as well as access to health care concentrated in demographics at higher risk of infection.

Trials for vaccines for Operation Warp Speed will be inclusive and diverse, chief adviser Moncef Slaoui said Friday. And once it is complete, he said they will be distributed widely.

“We are extremely cognizant of the importance of making sure that the vaccines, if and when they become available, are appropriately allocated in the population, on the basis of data … and on the basis of need,” he said.

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