A small minority of fully vaccinated people living in Minnesota have tested positive for COVID-19, though officials say the "breakthrough" infections are not especially worrisome, reports The Star Tribune.
None of the 89 infections in fully vaccinated Minnesotans have accounted for any of the state's COVID-19 deaths.
"Yes, people get COVID, but people in general do overall better," said Andrew Olson, MD, Minneapolis-based M Health Fairview's medical director for COVID-19 hospital medicine. "We have seen that both in patients in our system who are hospitalized and patients who are not hospitalized."
Minnesota reported March 24 that 1,454,834 residents had received at least one dose, with around 800,000 Minnesotans fully vaccinated, reports the Tribune. Based on the 800,000 estimate, the 89 known cases would equal about one infection per every 9,000 vaccinated.
State officials interviewed 72 of the fully vaccinated patients and found 30 had symptomatic COVID-19. Many were identified through routine testing in long-term care facilities.
The small fraction of fully vaccinated people who contract COVID-19 was expected, said Kris Ehresmann, RN, state infectious disease director. Clinical trials suggested the Pfizer and Moderna vaccines were 95 percent effective. Out of caution, the state is reviewing the cases to see if they have anything in common, such as a handling problem.
Two studies published March 23 in the New England Journal of Medicine and cited by The New York Times reflect similar findings. Only a small minority of those fully vaccinated test positive, and for those that do, cases tend to be mild.
The CDC is studying breakthrough cases, said Kristen Nordlund, agency spokesperson. The researchers are considering whether particular variants may play a role in such cases.
"Currently, there is no evidence that COVID-19 after vaccination is occurring because of changes in the virus," Ms. Nordlund told the Times.