Vax and Unvaxed Cases

As Dave’s notes indicate, he got an updated file from DOH.  We still are puzzled by some of the data and suspect either continuing processing lags or some unspecified errors.  Note that the charts show just absolute numbers, the vaxed population is larger than the unvaxed, so the per capita rate of cases is actually significantly lower.

Dave’s notes:

• MDH sent us refreshed breakthrough case data on 3/18/2022 in response to our Government Data Practices Act request, a week earlier than we expected based upon the agreed don monthly data set.
• We subtracted the daily breakthrough cases from the total daily cases downloaded from the Situation Update for COVID-19 web page https://www.health.state.mn.us/diseases/coronavirus/situation.html, resulting in the daily cases among the unvaccinated. We then computed a 7 day running average of cases among the vaccinated and unvaccinated for the charts below.
• There are some date mismatches in either the daily cases or the daily breakthrough cases. On a total of 15 days, mainly during the Omicron surge, have more reported daily breakthrough cases than total daily cases. Plotting 7 day running averages smooths out these inconsistencies.
• Starting on 12/25/2021 the average daily cases among the vaccinated exceeds the average daily cases among the unvaccinated.
• It is curious that the peak of Omicron cases among the vaccinated peaks on 1/07/2022 at 7466 cases per day, while the cases among the unvaccinated peaks 6 days later on 1/13/2022 at 6684 cases. It is unclear if the difference in peak dates is a epidemiology effect, or an artifact of MDK’s reporting. We also note that vaccinated cases far exceed unvaccinated cases  on the way up to the Omicron peak on 1/07/2022, but vaccinated and unvaccinated cases are much closer to equal on the way back down. MDH had admitted to  large backlog in processing case reports during Omicron, and it is possible that they still have not completely caught up in matching cases to vaccination records. This would account for the mismatch in peak dates among the vaccinated and unvaccinated, and minimal difference in cases after the Omicron peak.