Now, the bad news: "Our levels are still far too high," said Dr. Megan Ranney, an emergency physician at Lifespan Health System and associate professor at Brown University.
"We need those masks. We need those large social gatherings, honestly, shut down for the time being, until our country can come up with a comprehensive national strategy to get this virus under control."
More than 4.6 million Americans have been infected with Covid-19, and more than 154,000 have died from the disease, according to data from Johns Hopkins University.
The relentless death toll is projected to reach 173,000 by August 22, according to a new composite forecast from the US Centers for Disease Control and Prevention. That's an average of almost 1,000 US deaths every day for the next 30 days.
Across the country, public health experts are pleading for Americans to not let their guard down as social gatherings -- especially among younger people -- are fueling the crisis.
"What we are seeing today is different from March and April," Dr. Deborah Birx, the White House coronavirus response coordinator, told CNN's Dana Bash on Sunday. "It is extraordinarily widespread."
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Test positivity surges, but testing doesn't
It's not just recent spikes in new cases, hospitalizations and deaths that have doctors concerned. It's also the test positivity rate -- which is generally a good indicator of how rampantly the virus is spreading.
As of Sunday morning, the test positivity rate was rising in most states compared to last week, and 34 states had higher-than-recommended test positivity rates, according to Johns Hopkins.
"There are two things that are going on," said Dr. Ashish Jha, director of the Harvard Global Health Institute.
"One is the underlying level of infection is rising, which is obviously the thing we are most concerned about," Jha said.
"But in about 18 to 20 states, the number of tests that are being done is actually falling. And it's falling because our testing system is under such strain that we just can't even deliver the tests today that we were doing two weeks ago in about 18 to 20 states. That's very concerning because when cases are rising, and your number of tests are falling, that's a recipe for disaster."
Going backward
The CDC says new deaths are likely to increase in Alabama, Kentucky, New Jersey, Tennessee and Washington. Some of these states previously reported progress in their Covid-19 numbers, but are facing trouble again.
In New Jersey, officials reported "an extraordinary milestone" Thursday -- no new Covid-19 deaths in hospitals for at least 24 hours.
But Gov. Phil Murphy said the number of new Covid-19 cases jumped to an average of about 550 at the end of July -- up from around 350 per day at the end of June.
"We are standing in a very dangerous place," the governor said. New Jersey officers recently broke up a party of about 700 people, despite the state's restric
