COVID-19 ended the year in Minnesota with an 8% increase in cases in December compared to last year, when vaccines were just beginning to become available.

The late 2021 reversal was a marked contrast from six months ago, when many Minnesotans were feeling optimistic that the pandemic would finally fade away.

Masks had come off, restaurants and bars were busy and fans enjoyed the normalcy of watching the Twins at Target Field.

June saw just 4,231 new COVID-19 cases in the state, an 80% drop from May and the lowest monthly tally since the pandemic was first detected here in March 2020.

But COVID-19 continued to surprise, as it has done all along, and 2021 stopped being a year of hope with the virus offering up two new highly contagious variants, the second even more infectious than the first.

"2021 was the year of hope and optimism with the vaccines and that was a really important pivot point because all of a sudden we have a tool that could change the landscape," said Minnesota infectious disease director Kris Ehresmann.

From her perspective as an epidemiologist, the relaxation of COVID-19 safety measures and the desire to move on from a relentless disease put everyone at risk.

"It was too early for some of those decisions and I think we were a little concerned about how that would play," she said. "We saw with delta ... and the elimination of most of the mitigation, it was kind of a perfect storm for that variant to gain a foothold."

In August nearly 42,000 cases were diagnosed— 10 times what had been detected in June as the delta variant became the predominant strain in Minnesota.

The delta-fueled wave peaked in November at 123,000 cases. Although that was below the peak of 180,000 infections in November 2020, it still turned nearly 5,500 people with COVID-19 complications into patients at the state's hospitals and started a bed space capacity crunch that remains to this day.

"We were thinking maybe we were starting to see the light at the end of the tunnel," said Rich Danila, an infectious disease epidemiologist at the Minnesota Department of Health. "Then delta came and it was just a punch in the gut. Delta truly changed everything."

Every day since the pandemic began, Danila writes down the names of those who have lost their lives to COVID-19.

"People get so immune to the numbers," he said. "Each person left behind somebody."

The deadliest COVID-19 day in 2021 was Nov. 26, when 50 people died from the disease. It was the day after Thanksgiving. A day earlier, 35 people with COVID-19 died on the holiday.

"This pandemic is a tragedy. When we look back on it we see what a tragic loss of life it has been," Danila said.

But as more Minnesotans got one vaccine dose, then a second and then boosters, the death toll subsided 22% in 2021, according to preliminary data. Some deaths have yet to be reported to state health officials.

Since late March 2020, Minnesota had at least one COVID-19 death every day for 459 consecutive days. That ended July 1, which was the first of five days that month to record zero COVID-19 deaths.

The average age of those who die from COVID-19 has steadily fallen as more of Minnesota's senior population has become vaccinated.

"In 2020, particularly in the spring and early summer, we saw cases on fire in our long-term care facilities and we really saw the impact on our elders," said Ehresmann. "With the vaccination in 2021, that has really muted and it has made a huge difference in terms of mitigating against cases."

Of those 65 and older, 93% are fully vaccinated, compared to 65% for the 18 to 49 age group and 23% for those 5 to 11.

"We've seen over a 10-year drop in the average age of death," Ehresmann said. "We are seeing many more deaths in our younger, unvaccinated population than we saw before."

Minnesota ended 2021 with a pandemic total of 1,022,212 cases and 10,516 deaths. On average, 49,500 people were diagnosed with COVID-19 each month in 2021, exceeding the 2020 average of 42,800, even though most people were not vaccinated in the first year of the pandemic.

The stay-at-home orders and the closure of many businesses in 2020 account for some of the difference. But the virus became more virulent in 2021 and the introduction of omicron is likely to spark a new surge of cases in 2022.

The Mayo Clinic is estimating through its COVID-19 model that Minnesota's case rate could jump significantly. At the end of 2021, the state was seeing about 56 cases per 100,000 people, but that rate could increase to between 100 and 200 in the near future. At Minnesota's peak in 2020, the case rate topped at around 125 per 100,000.

State health officials agree.

"Given the virus' high level of activity we are not going to be able to avoid it," said Ehresmann. "The extent to which we see it is going to depend on how seriously people take it."

Staff writer Christopher Snowbeck contributed to this report.