Health officials have said since the introduction of the COVID-19 vaccines that they are extremely effective in preventing the virus and its symptoms, but that they are not 100%.
 
 Indeed, there have been rare cases where fully vaccinated people later get COVID-19, including in Minnesota, and health officials are investigating those cases to get a better understanding of the virus.
 
 In early March, the Minnesota Department of Health said it identified 14 of what are being called “Vaccine breakthrough cases” in the state. These are cases where an individual tests positive for COVID-19 14 days after receiving the two-dose series of vaccinations.
 
 Those individuals in Minnesota who have been identified as vaccine breakthrough cases have had either mild or no symptoms from the virus.
 
 Even so, health officials are investigating the cases to more fully understand the length of immunity from the vaccines. It could also help understand immune responses from specific groups of people with certain health issues… and if COVID variants impact susceptibility to COVID-19 infection after vaccination.
 
 Just over 500,000 people are fully vaccinated so far in Minnesota.
 
 Meanwhile, Johnson and Johnson’s one-dose vaccine has arrived in Minnesota and will be administered to health care workers and those over 65 years of age and older.
 
 While it’s been found to be less effective in preventing COVID symptoms when compared to Pfizer's and Moderna's vaccines, it has about the same effectiveness, over 90%, in preventing severe symptoms and death.*