The finding in Minnesota last week of the nation's first COVID-19 infection from a more contagious Brazilian variant is raising concerns that pandemic cases could accelerate, although more information is needed on the exact nature of the threat.
As with variants that have emerged in the United Kingdom and South Africa, scientists believe the strain spreads more easily and quickly than others, potentially sickening more people.
But health officials don't know for sure if it's spreading in Minnesota. The state Department of Health said last week that it identified the strain in a specimen from a resident who recently traveled to the South American nation. It's also not clear the extent to which immune system protection that's been stimulated by vaccines or a previous SARS-CoV-2 infection will work against the Brazil variant.
Worries over the variants come amid otherwise encouraging signs about the pandemic in Minnesota, with thousands of residents being vaccinated each day and a recent decline in new cases.
"We are in a very, very difficult period," said William Hanage, an epidemiologist with the Harvard T.H. Chan School of Public Health. "The variants of concern are ... serious causes of concern, but we don't know enough about them at the moment to be able to be definitive.
"And this is happening at a time when vaccines are beginning to become available and people are starting to feel like they're going to be able to relax. That's dangerous for a lot of reasons."
Minnesota reported on Saturday 1,087 new coronavirus cases and 19 more deaths due to complications from COVID-19. The seven-day rolling average for new cases fell to about 1,002 per day — the lowest reading since late September, according to the Star Tribune's coronavirus tracker.
The statewide tally for people who've received at least one vaccine dose increased by 35,568 in the latest data release, for a total of 381,204 people. That's about 6.7% of the state's population — up from 4% a week ago, according to Star Tribune estimates.