According to MDHHS, 246 people have had a positive test 14 or more days after receiving their second dose of the vaccine as of the end of March. The people who have tested positive have been asymptomatic or have had milder symptoms compared to unvaccinated people.
So far, more than 1.7 million Michigan residents have received complete doses of the vaccine. This means that .0001 of those vaccinated have gotten sick. Pfizer and Moderna vaccines are considered 95% and 94% effective respectively, meaning that the vaccines are not 100% effective, but if people do get sick, the infections tend to be less severe.
Of the positive cases, 129 had no data entered about hospitalizations, while 117 did have that information. Eleven were hospitalized, 103 were not, and three were marked as unknown.
This data contradicts a statement made by Gov. Gretchen Whitmer said last week.
"Zero percent of the people in our hospitals right now have been vaccinated, which tells you the vaccines work," she said.
Additionally, according to MDHHS, three people older than 65 have died. Two of those deaths were within three weeks of completion of vaccination.
Officials said the majority of the population develops full immunity within 14 days of completion of their vaccine series, but a small proportion appears to take longer to get a full antibody response.
The CDC is working to understand the risk characteristics of this group, MDHHS said.
The health department reiterated that the proportion of vaccinated people who have been symptomatic, hospitalized, or have died are lower than those who are unvaccinated.
Also, health officials said some of those people who have tested positive for COVID after getting vaccinated may have been continuing to test positive from a recent infection prior to being fully vaccinated.
The cases are being reviewed 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.