Lt. Gov. Peggy Flanagan has tested positive for a breakthrough case of COVID-19, she announced Saturday.

Flanagan received the positive test after caring for her 8-year-old daughter Siobhan, who tested positive on Oct. 22, she wrote on Twitter.

The lieutenant governor received the Moderna COVID-19 vaccine last spring.

"While I'm under the weather, our family is doing well, and we're thankful for the support of friends and family," she said in a series of tweets. "I'll be continuing to stay home to recover and make sure I don't get anyone else sick."

Flanagan said she and her husband, Tom, had been staying home for the past week to care for their daughter and avoid exposing others to the virus.

"I've experienced a lot of extreme feelings over the course of this pandemic, but nothing has compared to how I felt when our baby said she didn't feel well," she said. "Like many parents, I'm so grateful that vaccines will soon be available for our 5-11 year olds."

Her daughter had just started feeling better when Flanagan began experiencing cold-like symptoms, she said. A rapid test came back positive on Friday, and a PCR test, considered the most accurate way to detect COVID, confirmed that she had the virus.

"I want to be clear: This pandemic is not over, and we have to keep doing everything we can to keep our kids safe," Flanagan wrote. "Getting vaccinated isn't just about you — it's about protecting our little ones who are not yet eligible to be vaccinated."

Flanagan's brother Ron, who was in his 50s and battling cancer, died of COVID in 2020.

State breakthrough data last week showed a total of 51,586 COVID infections in nearly 3.2 million fully vaccinated Minnesotans — about 1.4% of that population. That included 5,759 breakthrough infections identified the week before, or about 36% of the total infections newly reported in that seven-day time frame.

The state also reported that 331 fully vaccinated Minnesotans had died of COVID, or 0.008% of all those who were vaccinated. COVID hospitalizations and deaths remain much more common in the unvaccinated population in Minnesota, according to state charts documenting the trends in severe pandemic activity by vaccination status.

COVID promises to be one of the issues on which Flanagan and Gov. Tim Walz will campaign as they seek re-election next year, when they plan to contrast the "tough calls" they say they made against the positions of Republicans they say moved Minnesota backward.

"Their dangerous views discouraging vaccines and masking and downplaying COVID put politics ahead of science and put lives at risk," Flanagan said earlier this month.