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Event Rates by Vax Status, Ages 50 to 64

By May 16, 2023Commentary

Once more on the 50 to 64 age group.

Dave’s notes:

  1. With the data release on 5/04/2023, the Minnesota Department of Health (MDH) changed the vaccination categories used to report breakthrough Covid cases, hospital admissions, and deaths. Prior to 5/04, the categories were Not Fully Vaccinated (those who are unvaccinated or only received one shot of the two shot vaccination series), Fully Vaccinated (received both primary series vaccination shots), and Boosted (those who had one or more booster shots, either the original booster or the new bivalent booster). The new categories published on 5/04 are Unvaccinated (not having received any vaccination shots), Vaccinated Without Bivalent Booster (those who received the two original vaccination shots and may have also received one or more of the original monovalent booster shots, Bivalent Boosted (received at least one bivalent booster).
  2. Note that those who received only one of the 2 original booster shots are not included in the new reporting categories. After an email exchange with MDH, we can confirm that the cases, hospital admissions, and deaths that occurred in the population who had only received 1 or 2 primary Covid vaccinations are not reported in the new version of the breakthrough data.
  3. The old category of “Not Fully Vaccinated” also included those with a single vaccination shot. Assuming that the single vaccination provided some protection, we would expect the new category of “Unvaccinated” to have higher rates of cases, admissions, and deaths per 100k since the new category excludes partially vaccinated individuals.
  4. As always, natural immunity from prior infections in not considered in this analysis. Despite repeated requests, MDH has not provided (and claims they do not possess) data on the vaccination status and reinfection status of Covid cases.
  5. By comparing the weekly data published on 4/27 using the old categories, and on 5/04 using the new categories, we are able to generate data for a total of 5 vaccination categories, 1). Unvaccinated (directly from the new data file), 2). Partially Vaccinated (the “Not Fully Vaccinated” category minus the new “Unvaccinated” category), 3). Fully Vaccinated (from the old data file), 4). Monovalent Boosted (from the old data file), and 5). Bivalent Boosted (from the new data file). The 4/27/23 data file ends 4/2/23. In subsequent weeks there are typically a small number of changes to the prior reported data. By combining the data from 2 weeks as we did we are potentially missing these minor changes, but we expect them to be of a relatively small magnitude.
  6. Note that this will be the only time we can generate these types of charts with all 5 vaccination categories. Since MDH will only publish the 3 new vaccination categories going forward we won’t be able generate the partially vaccinated category in the future, and the categories we have taken from the old reporting (fully vaccinated and monovalent boosted) will be obsolete in future weeks.
  7. Fig.1, Minnesota Covid Cases Per Week by Vaccination Status, 50-64 Age Group: In raw numbers of cases, the unvaccinated have not had the highest number  of weekly cases since the summer of 2021. There are very few partially vaccinated cases likely because most people in this age group who got the first vaccination shot went on to get the second as well.
  8. Fig. 2, Minnesota Covid Cases Per Week Per 100k by Vaccination Status, 50-64 Age Group: In this chart we convert the raw number of cases in Fig. 1 to cases per 100k. For this age group the unvaccinated had the highest case rate only until December 2021, after that time the vaccinated and then the boosted narrowly had higher case rates. Since May of 2022 the partially vaccinated have consistently had the lowest case rates, by a small margin.
  9. Fig. 3, Minnesota Covid Hospital Admissions Per Week by Vaccination Status, 50-64 Age Group: This group is fairly highly vaccinated and boosted, causing the raw numbers of admissions to be highest among the monovalent boosted.
  10. Fig. 4, Minnesota Covid Hospital Admissions Per 100k Per Week by Vaccination Status, 50-64 Age Group: The unvaccinated had the highest hospital admission rates until February 2022. Since then admissions rates have been roughly the same regardless of vaccination status.
  11. Fig. 5, Minnesota Covid Deaths Per Week by Vaccination Status, 50-64 Age Group: As with hospital admissions, the unvaccinated had the highest number of deaths until February 2022, and since then there have been very few Covid deaths in this age group for any vaccination status.
  12. Fig. 6, Minnesota Covid Deaths Per 100k Per Week by Vaccination Status, 50-64 Age Group: Very low deaths rates regardless of vaccination status since February 2022.

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