By Erin Hassanzadeh

MINNEAPOLIS (WCCO) — More than 65,000 vaccinated Minnesotans have contracted COVID-19, according to health officials. These breakthrough cases account for about 2% of the more than 3 million Minnesotans who’ve been vaccinated against the virus.

Currently, the state is giving out more booster shots than first doses. Doctors say that the boosters will help keep more breakthrough cases out of already crowded hospital rooms.

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More than 660,000 Minnesotans have received a booster shot — that’s about 20% of the fully-vaccinated population in Minnesota. With those figures, Minnesota is third in the nation for the percentage of the population with boosted COVID immunity.

Still, there are restrictions in Minnesota on who can get a booster dose. For those who got the Pfizer or Moderna shots, boosters are only available for those who are seniors, living in long-term care facilities or are at risk of certain underlying conditions.

Meanwhile, all Minnesotans who got the Johnson & Johnson shot are encouraged to get a booster at least two months after their first dose.

So, when does the effectiveness of the initial COVID-19 vaccine shots begin to wear off?

“It does actually look like antibody levels start to fall around that four to six month window,” said Dr. Mark Sannes, an infections disease expert with HealthPartners. “I think we’re starting to see the clinical cases correspond with that.”

Sannes says that the combination of waning immunity and the highly-contagious Delta variant is causing the current surge of COVID-19 cases in Minnesota.

Dr. Susan Kline, the director of the infectious disease division at the University of Minnesota, says that more breakthrough cases are being seen with people who got the Pfizer vaccine.

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“With the Moderna vaccine, the immunity seems to be lasting a little longer,” she said.

States like Colorado are making booster shots available to anyone over the age of 18. However, health leaders in Minnesota are more hesitant to make booster shots more widely available.

“There’s concern that if there were potential side effects from the vaccine, you have to weight the potential side effects against the potential benefits,” Kline said.

Still, experts say they could imagine Minnesota lowering restrictions on booster shots in the near future.

“I think that would be something to watch for in the next several days,” Sannes said.

WCCO reached out to the Minnesota Department of Health and asked about expanding booster eligibility. Health officials said they’ll make that decision based on guidance from the Centers for Disease Control and Prevention and the U.S. Food and Drug Administration.

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Erin Hassanzadeh