Variant strains now dominate new COVID-19 cases, but vaccines are holding them off so far

State health officials say a majority of Minnesota’s positive COVID-19 cases are now variants of the virus.

According to recent data released by the CDC, about 72% of positive COVID-19 cases are the B117 variant.

The Minnesota Department of Health reports similar numbers. MDH officials estimate about 75% of new positive infections in Minnesota are from the B117 variant, first detected in the United Kingdom, and as much as 85% of positive cases overall are due to variants.

“It is a concern because these variants are more transmissible at the least,” said Dr. Frank Rhame, an infectious disease specialist with Allina Health.

While there is still ongoing research on how effective the COVID-19 vaccines are against the variants, Rhame says for those vaccinated who still get “breakthrough” infections, the data shows a majority of those cases have recovered just fine.

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“The people are generally quite well. In fact, usually asymptomatic,” Rhame said. “The bottom line is there are going to be ‘breakthrough’ infections in people that have relatively normal immune systems, even if they have COVID, the vaccine or both. But if your immune system is anywhere near decent, it’s not going to be a severe illness.”

But with questions on how long protection against COVID-19 could last with the variants circulating, two encouraging new studies suggest people who recovered from the virus had some immunity long after antibodies faded — even a year later.

Some experts now suggest the vaccine might give a super-charged immunity to people who had the virus.

Earlier this week, Dr. Anthony Fauci, White House chief medical advisor, says it’s unclear when Americans might need a booster shot.

"I don’t anticipate that the durability of the vaccine protection is going to be infinite. It’s just not," Fauci said. "So I would imagine we will need at some time a booster."