Wellington, New Zealand CNN  — 

After weeks of lockdown, New Zealand has achieved its ambitious goal of eliminating the coronavirus.

But the country isn’t celebrating yet.

Over the past few days, newly diagnosed infections have been in the single digits. And on Monday, New Zealand reported just one new case.

“That does give us confidence that we’ve achieved our goal of elimination, which never meant zero but it does mean we know where our cases are coming from,” Ashley Bloomfield, New Zealand’s Director General of Health, said on Monday, adding that there was only one case since April 1 where authorities were still investigating the source of infection.

Monday was the final day of almost five weeks of strict level four lockdown measures, which New Zealand’s Prime Minister Jacinda Ardern described as “the strictest constraints placed on New Zealanders in modern history.”

On Tuesday, the country eased into a less restrictive lockdown, with 400,000 more New Zealanders heading back to work and 75% of the country’s economy operating, according to Ardern. The new level three restrictions also mean that New Zealanders will be able to hold small funerals and buy takeaways.

New Zealand has reported 19 deaths and 1,472 confirmed and probable coronavirus cases, according to Johns Hopkins University. Of those, 1,214 – of 82% of confirmed and probably cases – have recovered, the Ministry of Health said Tuesday.

But while New Zealand’s success in eliminating the virus might seem like cause for celebration, Ardern is still urging vigilance.

“We are not out of the woods,” she said at a press conference Tuesday. “(Level three) is a recovery room of sorts to assess if the incredible work that New Zealanders have done … has worked.”

Jacinda Ardern facebook live
Jacinda Ardern hosts coronavirus Facebook Live from her home
01:32 - Source: CNN

When it comes to what worked, New Zealand had some advantages in tackling the virus. It had the benefit of time – New Zealand confirmed its first case of coronavirus on February 28, well over a month after the United States confirmed its first case.

It’s a relatively remote island nation, and relatively few flights transit through New Zealand. It’s also centrally governed, meaning it doesn’t have states like the US or its neighbor Australia.

But the real key to New Zealand’s success appears to be an approach that could be applied anywhere – moving swiftly, testing widely, and relying heavily on good science.

Moving swiftly

Like many countries, New Zealand had models that showed that a potential coronavirus outbreak could be devastating if no action was taken. Unlike some other countries, New Zealand responded relatively fast.

When Ardern announced on March 14 that anyone entering the country would need to self isolate for two weeks, it was among the toughest border restrictions in the world. At the time, the country had six cases.

When, on March 19, Ardern banned foreigners from entering the country, there were 28 confirmed cases.