BERLIN (AP) — For a time, Germany seemed to have solved the puzzle of how to quell COVID-19.

Germans enjoyed a largely relaxed summer with many restrictions lifted, the dividend of a rapid response to the initial outbreak and a reliance on early and aggressive testing that won wide praise. That brought the number of daily COVID-19 cases down from a peak of more than 6,000 in late March to the mere few hundreds by the warmer months.

After closing all non-essential shops, as well as schools, bars, restaurants and clubs, and banning gatherings of more than two people in public at the end of March, Germany’s 16 states were able to gradually restart public life in May.

Many schools squeezed in a few lessons before summer break and then began reopening fully by the end of August. Restaurants resumed serving customers . And with the borders again open, holiday-happy Germans took to the roads, desperate to get out after being cooped up.

Government rules on social distancing, hygiene measures and mask wearing remained in place but, as Germans' early vigilance slid into complacency, adherence began to slip and pictures of young people partying in tight groups and other violations prompted Chancellor Angela Merkel to issue a plea for people to fall back in line.

“We don’t want to be a country in which the streets and transport systems only belong to the toughest and the youth and everyone else, especially the elderly, hardly dare come out because they fear the infection,” she said in July.

Those entreaties were not enough, and cases began to rise exponentially as fall set in, prompting officials to institute a “wave-breaker” partial shutdown on Nov. 2. Scientists warned that if the trend was not broken, the country was on pace to see 400,000 new daily cases by Christmas.

“In order to get the pandemic in control, we needed to pull the emergency brake,” said Health Minister Jens Spahn, who himself was infected with and recovered from COVID-19. “The situation is serious.”

Drawing on lessons learned in the country’s first lockdown, mask regulations were extended to include some crowded streets, restaurants were again closed for in-house dining, and restrictions were placed on how many people could gather together. Schools and shops, however, were allowed to remain open.

Infections continued to rise to new daily records nearly four times the March peak, then leveled off by the end of November — a sign the measures were working. But cases remained high, prompting the government to extend the restrictions until Jan. 10 and then impose stricter measures.

Despite the recent rise, Germany is still the envy of many, with a third of the deaths of Britain and Italy, and just under a third of those of France — all of which have smaller populations.

By mid-December, Germany had reported 1,588 cases and 26.2 deaths per 100,000 population.

A robust hospital and health care system — in the past derided by economists as bloated and overly expensive — has meant that in both phases of the pandemic, Germany always had beds available and has even been able to take in critical patients from its European neighbors.

Years of running a budget surplus, widely criticized as slowing economic growth, meant that the government was able to announce rescue plans for business in March totaling more than 1 trillion euros ($1.18 trillion). That was followed by a 130 billion-euro stimulus package.

Germany also has kept unemployment down through extensive use of a salary-support program that has been in place for years, which sees the federal labor agency pay at least 60% of the salary of employees who are on reduced or zero hours.

From the start of the crisis, Merkel’s background as a scientist before she entered politics and her cautious, matter-of-fact approach has resonated with most Germans.

The latest polls show more than 80% approve of the lockdown measures or think they should be stricter. Less than 15% say they go too far.

“The winter will be difficult — four long difficult months,” Merkel said bluntly as the restrictions were enacted. “But it will end.”