The coronavirus death toll in the U.S. had barely surpassed 100 in March when a group of counties in the San Francisco Bay Area enacted a sweeping “shelter-in-place” order.

The order had residents going to Google to find out what it meant. Fast-forward a month, and more than 310 million Americans are familiar with what at first seemed like a drastic response, with just eight states holding out against “stay-at home” orders amid this public health emergency.

The March 16 order was called "unprecedented" at the time by county public health officer Dr. Sara Cody, The Mercury News of San Jose reported.

That decisive early action – followed soon by Gov. Gavin Newsom – has California confident in its fight against the novel coronavirus, despite the state having the country’s second-most populated city in Los Angeles, said Dr. Josh Salomon, a professor of medicine at Stanford University.

“One thing that I think is known is that the earlier you’re able to act decisively to stop rise in infectious, the more that that will pay off in terms of higher impact in flattening the curve,” said Salomon, also the director of the Prevention Policy Modeling Lab at Stanford Medicine.

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"I think the move to make these decisions quickly, to avoid further delays once the extent of spread and its rise became clear, have been absolutely vital and deserve a lot of the credit for us being at a place right now that’s much better than where we might have been had the epidemic continued to spread," Salomon said.

California is projected to reach its peak for COVID-19 deaths on Wednesday, with an estimated 66 deaths, according to the University of Washington’s Institute for Health Metrics and Evaluation (IHME). New York state, which has become the epicenter of the country's coronavirus outbreak, by comparison, had nearly 800 deaths on Wednesday and, according to the IHME's data, hit its daily death peak on Thursday.

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California reported its first coronavirus case on Jan. 26 – New York reported its first case more than a month later on March 1. Newsom enacted California’s stay-at-home order on March 19; New York’s order came three days later.

At the time, Newsom said about 56% of the state’s population of nearly 40 million would contract the virus, according to data analyzed by his office. He added about 19,543 people would have to be hospitalized under that assumption, well beyond the existing surge capacity of California’s system, which includes about 10,000 beds across 416 hospitals.

Newsom's office did not respond to USA TODAY's request for comment.

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“If we meet this moment, we can truly bend the curve to reduce the need to surge," he said at the time. "To reduce the need to have to go out and begin to cobble all those assets together — though I want you to know we’re doing just that.”

He added, “I can assure you home isolation is not my preferred choice. I know it’s not yours. But, it’s a necessary one.”

Los Angeles has been equally decisive in its action against the spread of coronavirus.

The Centers for Disease Control and Prevention on April 3 recommended people wear cloth masks while engaging in public. Four days later, Los Angeles Mayor Eric Garcetti made that recommendation a citywide mandate. The city's "Safer At Home" order, originally planned to end April 19, was also recently extended to May 15.

“We need to protect every worker on the front lines of this crisis,” Garcetti said in a statement. “Each one of us is a first responder in this emergency. Every employer should keep employees safe, and so should Angelenos patronizing these businesses. Cover up. Keep your distance. Save lives. It’s that simple.”

As of Sunday night, Los Angeles had about 8,900 confirmed COVID-19 cases, according to data from Johns Hopkins University. New York City, on the other hand, had more than 100,000 confirmed cases and nearly 7,000 deaths.

Salomon, who lives in Santa Clara County, didn’t want to compare California’s response to New York’s but said the Golden State’s actions served as an example for other states.

“We do know that earlier action in trying to curb the spread as the epidemic is rising at this very steep, exponential rate, is very important and delay of even a few days can make a profound difference even a week or two later in terms of where the epidemic is and where it’s heading,” he said.

'Worst mistake' US could make now is to end social distancing too soon

Now, with millions of Americans out of work, President Donald Trump is pushing to “reopen” the country. Doing so too soon, however, could have dire consequences, Salomon said.

“The worst mistake we could make right now would be to lift the current public health orders too quickly,” Salomon said. “I think one thing that’s almost guaranteed is that if we lift the orders too quickly, there will be a resurgence in the spread of cases.”

Salomon called for "systems that bolster the health care system" and nationwide testing. The latter point was one Trump on Thursday said was unnecessary.

"We want to have it and we’re going to see if we have it," Trump said during a coronavirus task force briefing. "Do you need it? No. Is it a nice thing to do? Yes. We’re talking about 325 million people and that’s not going to happen, as you can imagine and it would never happen with anyone else, either."

Being able to test people for the coronavirus and effectively quarantine people who are infected is critical to being able to lift the current social distancing measures, Salomon said.

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"We need more information that will let us know what is going on with ongoing spread in the community," Salomon said. "Right now, case counts give us a quite imperfect signal of that because they reflect testing volume, which is inadequate. They reflect delays to when people are symptomatic and able to be detected.

"Right now, case counts don’t give us the signal we’d like to have, which is, what is the ongoing risk in communities."

California is 'aggressively preparing' for a surge of coronavirus cases

Last week, Newsom tweeted that California isn't "waiting around, hoping we'll get the equipment we need" and told MSNBC the state had secured "upwards of 200 million masks."

Shortages of personal protective equipment (PPE) have been well-documented in the nation throughout the coronavirus crisis.

He said the supplies will come to the state over the next few weeks and added he's looking at potentially exporting the masks to other states in need. The state last week sent 500 state-owned ventilators to the Strategic National Stockpile.

“We still have a long road ahead of us in the Golden State — and we’re aggressively preparing for a surge — but we can’t turn our back on Americans whose lives depend on having a ventilator now," Newsom said in a press release when the ventilators were sent out.

"We’re meeting this moment with compassion. I know that if the tables were turned and we were experiencing a hospital surge, other states would come to our aid and provide ventilators just as we are today.”

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IHME's projections say California's peak for resource use is coming Monday. Last week, Newsom announced the state secured more than 4,600 additional hospital beds at alternate care sites. Overall, the goal is to add 50,000 beds to the state's capacity, which is nearly 75,000 beds, according to the governor's office.

The U.S. Naval Ship Mercy is already docked at the Port of Los Angeles.

"This is an all hands on deck effort, and I am extremely grateful to all of our partners in the medical community, the private sector and across government for helping us get this far," Newsom said in a press release. "All of these efforts will only pay off if we continue to slow the spread of the virus."