At least 89 people in Minnesota who have completed the vaccine series have tested positive for COVID-19.
Called "breakthrough" cases by Minnesota Department of Health infectious disease expert Kris Ehresmann, these cases represent a microscopic proportion of the nearly 800,000 Minnesotans who have been fully vaccinated for more than two weeks.
As of Mar. 22, the state reported that 862,955 people are completely vaccinated, meaning they received both doses of the Pfizer or Modern vaccine, or the single-shot Johnson & Johnson vaccine.
It's been at least two weeks since completing the vaccination process for approximately 800,000 of those Minnesotans, which represents the time needed to allow the second dose (or single-dose J&J shot) to take maximum effect.
The Moderna and Pfizer vaccines are approximately 95% effective in preventing the original COVID-19 strain, while trials of the J&J vaccine in the U.S. were 72% effective, so it would be expected that at least five of every 100 people vaccinated would still potentially contract COVID-19 if exposed to the virus.
Eighty-nine cases from 800,000 people equates to 0.011125% testing positive after vaccination, or about one in every 9,000 people.
That said, this figure isn't a true representation of how effective the vaccine is, as it's unknown how many of those 800,000 fully vaccinated people have been exposed to COVID-19 since they got their shots.
Nonetheless, Ehresmann said "we should not be fooled" into seeing breakthrough cases as a reason "to doubt the vaccine effectiveness."
More encouraging than the number of people getting COVID-19 after being vaccinated is that none of the 89 patients who tested positive after completing the vaccine series have died. In addition, only 30 of the 72 patients the health department interviewed said they were symptomatic, the Star Tribune reports.
As well as reducing the risk of getting COVID in the first place, the three vaccines available in the U.S. currently are also effective at reducing severe illness from the virus.
State officials are encouraging all Minnesotans who are eligible for the vaccine to get the shot, with state epidemiologist Dr. Ruth Lynfield saying Tuesday that it's a race between the vaccine and the more contagious B.1.1.7 variant of the coronavirus, which is now confirmed as the dominant strain in Minnesota.
"We have now identified 479 cases of this variant. We estimated that 50-65% of Covid-positive specimens tested Mar. 16-20 were B.1.1.7. This is an increase compared with specimens tested Mar. 10-15 in which 38-44% of those specimens were estimated to be B.1.1.7," said Lynfield.
Studies have shown that vaccines are effective against the B.1.1.7 variant, which is known to be more transmissible and capable of causing more severe illness than the SARS-CoV-2 strain that started the pandemic.