Of the 1.7 million people who are fully vaccinated in Michigan, 246 people tested positive for COVID-19

• Out of 1.7 million fully vaccinated people in Michigan, 246 tested positive for COVID-19.
• That places the breakthrough rate of fully-vaccinated cases at a fraction of a percent.
• As of April 4, nearly 3 million Michigan residents have received at least one vaccine dose.

Less than 250 of the 1.7 million fully vaccinated people in Michigan have tested positive for COVID-19, state officials said Monday, a finding that supports the findings of clinical studies that the vaccines are extremely effective.

The Michigan Department of Health and Human Services said 246 cases were reported between January 1 and March 31, and that they had tested positive 14 or more days after their second dose of the COVID-19 vaccine - meaning a fraction of a percent of those who were fully vaccinated are contracting the virus.

Essentially, .0001% of those in Michigan who have had both doses have tested positive for COVID-19, according to Fox 2 Detroit.

No vaccine 100% guarantees that someone who receives it will never get ill. But those developed for COVID-19 come close, with the shots from Pfizer-BioNTech and Moderna both coming in at a roughly 95% efficacy rate in clinical trials. The real world is, of course, different, and the US Centers for Disease Control and Prevention, among others, is continuing to assess how the vaccines perform outside clinical settings.

While national data is limited, the available evidence indicates that so-called "breakthrough" cases are far from the norm. In Minnesota, for example, only 89 out of 800,000 fully vaccinated people tested positive, a figure so low it shocked local health officials.

There are also other factors to consider, such as whether the rare positive cases post-vaccination are among people who were exposed to the virus before they were fully inoculated.

In Michigan, MDHHS spokeswoman Lynn Sutfin told the Detroit News that hospitalization data was available for 117 of those who tested positive - 11 were hospitalized, 103 were not, and the status of three remains unknown.

"Some of these individuals may ultimately be excluded from this list due to continuing to test positive from a recent infection prior to being fully vaccinated," Sutfin told the outlet in an email.

"These cases are undergoing further review to determine if they meet other CDC criteria for determination of potential breakthrough, including the absence of a positive antigen or PCR test less than 45 days prior to the post-vaccination positive test," she continued. "In general, these persons have been more likely to be asymptomatic or mildly symptomatic compared with vaccinated persons."

As of April 4, nearly 3 million Michigan residents - about 36.7% of the state's population - have been vaccinated with at least one dose, according to state data.

According to data collected by The New York Times, the six metropolitan areas with the highest rates of new reported cases are in Michigan.

FOX 2 reported some of those who are fully vaccinated and have tested positive for COVID-19 "may have been continuing to test positive from a recent infection prior to being fully vaccinated," according to health officials.

The news comes after 89 fully vaccinated people tested positive for COVID-19 in Minnesota last month, out of the 800,000 who have received both doses of the vaccine at the time. The breakthrough rate of the Minnesota cases was around 0.01%.

"That's well below one-tenth of one percent - an incredibly small number of cases that dramatically illustrates how effective these vaccines are," state infectious disease director Kris Ehresmann said in a March 24 briefing of the Minnesota incident.