(CNN) When Covid-19 suddenly ravaged New York, hospitals looked "apocalyptic." Refrigerated trucks turned into morgues because there wasn't enough space for all the victims.
That was March. Three months later, the state had "done a full 180, from worst to first," Gov. Andrew Cuomo said.
Now, the rates of infection, hospitalizations or deaths have plummeted in New York and several other states -- paving the way for full economic reopenings.
It's the opposite of what's happening in most of the US, where the virus is surging and more than half the states have paused or backtracked their reopenings.
Here's how some states have helped get coronavirus under control -- and what they're doing to make sure it stays that way:
How well the state is doing:
Connecticut has lowest test positivity rate in the US -- a remarkable 0.8% as of Tuesday. That means of all the Covid-19 diagnostic tests performed, only 0.8% turn out to be positive.
Most other states have test positivity rates higher than 5%, which is above the World Health Organization's recommended threshold for reopening.
Connecticut has also maintained some of the lowest rates of transmission (R numbers) in the country. An R number represents how many people each infected person, on average, is likely to go on and infect.
Connecticut has kept its R number under 1.0 for more than three months, from April 3 through at least July 20. That means fewer and fewer people are getting infected in the state.
How they tried to get their numbers down:
Connecticut started requiring face masks statewide on April 20. Many other states didn't start mandating masks until two months later.
It also reopened later than many states, starting on May 20.
And like New York and New Jersey, Connecticut has required visitors from states with high rates of Covid-19 to quarantine for 14 days
How they're planning to keep a lid on the virus:
Even though Connecticut had some of the best numbers in the US, Gov. Ned Lamont decided not to move forward with Phase 3 reopening plans on July 6. That meant bars must remain closed, and restaurants must stay at 50% capacity.
"Look, I like a beer at the bar as much as the next person. I know how frustrating this can be," Lamont said. "But right now, with this pandemic flaring up in a majority of other states, this is not the time to take a risk."
Lamont also said the state would hold off on allowing outdoor gatherings of more than 100 people.
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How well the state is doing:
Vermont reached an extraordinary milestone this week, with no new Covid-19 deaths reported for an entire month. From June 19 through at least July 20, the state's death toll stayed the same -- 56.
It also has the 2nd-lowest test positivity rate in the nation -- 0.81% as of Tuesday, according to Johns Hopkins data. The Green Mountain State has the 2nd-lowest number of coronavirus cases per capita.
How they helped keep their numbers low:
Contact tracing has steadily improved in Vermont -- from an average of 2.7 contacts made per case in April to 4.8 contacts made per case in June.
As of this month, at least 2,469 contacts have been identified, the Vermont Department of Health said.
"172 contacts became a COVID-19 case," the health department said. "This means that this group of people knew to stay home, and likely did not spread the virus further."
How they're planning to keep Covid-19 under control:
When schools reopen this fall, "All staff and students are required to wear facial coverings while in the building, as well as outside where physical distancing cannot be maintained," according to guidance issued last month by state health and education officials. That guidance could change before the school year starts.
And despite much better Covid-19 rates than most of the country, Gov. Phil Scott announced last week that Vermont's state of emergency will be extended for another month.
"It's the vehicle we need to keep certain protections in place (and) control outbreaks as they come up, so we can keep the economy open and manage this ongoing crisis," Scott said.
"As long as the data stays consistent, we will stick with our effort to incrementally lift restrictions and get closer to a point where this order is no longer necessary."
How much the state improved:
New York started Phase 2 of its reopening on May 29, allowing office-based work, in-store retail shopping and some barbershop services to resume in much of the state.
Yet between May 29 and July 10, average daily new cases in New York state has dropped about 55% -- from about 1,447 new cases a day to 651 cases a day, according to data from Johns Hopkins.
New York has by far the most Covid-19 deaths in the country, with more than 32,000 since the pandemic began.
But on July 13, New York City reported no new deaths from Covid-19 for the first time in months.
What New York state did:
On March 20, as Covid-19 was spiraling out of control in New York, Gov. Andrew Cuomo announced all employees of nonessential businesses must stay home. It was one of the earliest shutdown mandates in the country.
"If someone is unhappy, if somebody wants to blame someone, or complain about someone, blame me. There is no one else who is responsible for this decision," Cuomo said that day. "This is not life as usual. And accept it and realize it and deal with it."
And at a time when testing was scarce across the country, New York tried to ramp up capabilities on its own. With FDA approval, New York state announced on March 13 it could authorize 28 public and private labs to start testing for coronavirus -- the first state to do so.
"We're hunting positives," Cuomo said in March. "We're hunting positives so we can isolate them and reduce the spread."
New Yorkers tuned into Cuomo's daily briefings for updates on the virus and how to stay safe. During his 111th and final daily briefing on June 19, Cuomo said the state had gone "from worst to first."
He credited residents who kept social distancing, stayed home, and wore masks when they had to go out in public.
"This wasn't only about what government did. This was about what people did," Cuomo said. "Together, New Yorkers bent the curve because we acted responsibly and we looked out for each other. Now, we must stay the course."
How they're planning to stay the course:
As a popular tourist destination, New York is trying to prevent visitors from spreading the virus. So anyone coming from a state where coronavirus is surging must quarantine for 14 days upon arrival.
"The quarantine applies to any person arriving from a state with a positive test rate higher than 10 per 100,000 residents over a 7-day rolling average or a state with a 10% or higher positivity rate over a 7-day rolling average," the governor's office said.
As of Tuesday, 22 states were on that travel advisory. Those arriving at a New York airport must fill out a traveler form.
"Travelers who leave the airport without completing the form will be subject to a $2,000 fine and may be brought to a hearing and ordered to complete mandatory quarantine," the governor's office said.
New York also released concrete metrics for when to allow schools to reopen, and when classes would need to go virtual if the situation gets worse.
While some have accused Cuomo of prematurely taking a victory lap, the governor's website stresses the fight is not over:
"Coronavirus is still active in New York," the top of the website reads. "We have to be smart. Wear a mask and maintain 6 feet distance in public."
How well the state has cracked down on Covid-19:
Maine's 1% test positivity rate Tuesday was the third best in the country. Hospitalizations keep going down. And Covid-19 deaths have dropped 40% this past week compared to the previous week as of Monday.
Overall, Maine is one of the best-performing states in several metrics, according to CovidExitStrategy.org, which tracks each state's progress on the White House gating criteria.
How they helped clamp down the virus:
Despite improving numbers by late April, Gov. Janet Mills decided to extend her stay-at-home order for another month -- though some types of businesses were allowed to reopen with stringent safety measures. She also enacted one of the earliest mask mandates, which took effect May 1.
And state health officials addressed racial and ethnic disparities, working directly with leaders of minority and tribal groups.
"Here in Maine, black people comprise only 1.4% of the population, but account for about 24% of all COVID-19 cases," the health department said in late June.
The state health department "also translated public health information about COVID-19 into as many as 11 different languages to ensure that everyone in Maine knows how to stay safe," spokesperon Jackie Farwell said.
How they plan to keep Covid-19 under control:
It can be difficult or impossible for coronavirus patients to safely isolate if they live in crowded homes or with high-risk individuals. So working with the state housing authority, Maine established safe quarantine and isolation sites in several cities "for individuals who lack the ability to safely quarantine or isolate at home."
Maine has also postponed the reopening of indoor bar service until further notice after seeing other states' spikes in Covid-19 cases -- including new outbreaks that were linked to indoor bars.
But as its Covid-19 numbers have improved, "Maine has reopened the majority of its economy."
How much the state improved:
Massachusetts started reopening on May 25. But since then, the rate of new cases has gone down, not up.
Between May 25 and July 10, the rate of daily new cases in Massachusetts has dropped by 75%, according to data from Johns Hopkins University.
Between April 15 and July 14, Covid-19 hospitalizations have dropped by about 84%, and the rate of new deaths has dropped by about 95%, according to data from the Massachusetts Department of Health.
How they helped quell coronavirus:
Massachusetts waited to start reopening and was one of the last states to do so.
It also enacted a mask mandate before most other states did, on May 6. But unlike some states, the mandate in Massachusetts also applies to outdoor public areas where it might not be possible to stay 6 feet away from others.
How they're planning to keep Covid-19 under control:
Massachusetts is doubling down on testing to try to snuff out coronavirus in the state.
This month, Gov. Charlie Baker announced a "Stop the Spread" testing initiative that will last until mid-August.
The effort will focus on eight communities where the rates of Covid-19 are higher than the statewide average.
"The goal of this initiative is to provide widespread asymptomatic testing in an easy-to-access location within these communities" to help stop community spread, Baker said.
And Massachusetts is aiming to resume classroom education this fall -- but with face masks and distancing rules.
"Students in grade 2 and above are required to wear a mask/face covering that covers their nose and mouth," according to initial guidance from the state education department. The same applies to teachers and staff members.
For those unable to wear a mask, face shields may be used. And mask breaks should occur throughout the day if there's adequate distancing or ventilation.
How the state has improved:
New Jersey was hit hard early in this pandemic, with hospitalizations and deaths soaring. The state has seen the highest rate of Covid-19 deaths per capita: 177 per 100,000 people.
But the rate of new Covid-19 deaths has improved dramatically, according Covid19-projections.com, a data tracking resource cited by the Centers for Disease Control and Prevention.
As of Monday, the number of new Covid-19 deaths from the past week dropped by 53% compared to the previous week. Hospitalizations are also going down.
New Jersey also has one of the lowest test positivity rates in the country -- about 1.4% as of Tuesday.
How New Jersey helped changed its course:
In mid-March, Gov. Phil Murphy activated the National Guard and issued sweeping orders, including:
-- The closure of all schools and universities starting on March 18
-- The closure of all casinos, racetracks, theaters and gyms
-- The closure of all nonessential retail, recreational and entertainment businesses after 8 p.m. each day
New Jersey was the first state to issue a mask mandate, back on April 8.
Businesses must provide masks to employees and deny entry to any customer who refuse to wear them inside the business. Those riding public transit in the state must also wear face masks.
New Jersey also joined forces with New York and Connecticut on requiring visitors from hot-spot states to quarantine for 14 days.
How New Jersey is trying to keep Covid-19 under control:
Officials are urging residents not to get complacent just because the numbers have improved.
"Our rate of transmission is in a good place today, but only a week ago ... it was above 1.0," the governor said last week.
"And if we change course, it's going to not only rise, but so will the number of positive test results, so will the number of hospitalizations, and so will the number, sadly, of residents who pass."