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Who Is Contracting Covid-19 in NC? Post-Vaccinated, Reinfected, and the Not Fully Vaccinated

Yesterday’s NC Threat-Free Index included the following findings:

  • As of November 8, there had been 12,293 reinfections for those with prior lab-confirmed cases of Covid-19, and the estimated reinfection rate was just over 0.8% (note: for reasons discussed here, the actual reinfection rate is likely much lower than the estimated rate)
  • As of October 23, per the most recent update from DHHS, there had been 91,047 post-vaccination infections, and the estimated post-vaccination infection rate was nearly 1.7%  (note: given how strictly DHHS defines a “post-vaccination infection” — someone must be at least two weeks past receiving the second of two injections; anyone with only one injection or within two weeks of receiving the second “counts” as an unvaccinated case of Covid — the actual post-vaccination infection rate could be much higher than the estimated rate)

I started compiling these statistics after the state Department of Health and Humans Services (DHHS) started reporting data on reinfections and post-vaccination infections. In October, DHHS began to identify reinfections among its daily case counts. DHHS’ weekly counts of post-vaccination infections lag by a few weeks, but the two data counts overlap sufficiently now to produce the following graph.

It shows how three weeks’ worth of lab-confirmed Covid-19 infections break down according to three categories: reinfections, post-vaccination cases, and cases to unvaccinated or not fully vaccinated individuals.*

Who Is Contracting Covid-19 in NC? Cases from Oct. 2–23


Source: DHHS (Daily cases, total cases by specimen date, and Respiratory Surveillance: October 24 – October 30, 2021); data as published on Nov. 8, 2021

Here are the raw numbers behind the graph covering the period from Oct. 2–23:

  • Total cases by specimen date: 51,801
  • Post-vaccinated infections: 13,797 (26.63%)
  • Reinfections: 962 (1.86%)
  • Cases to unvaccinated or not fully vaccinated* individuals: 37,042 (71.51%)

Some highlights from those numbers:

  • There were about 2.7 times more lab-confirmed Covid-19 cases to unvaccinated or not fully vaccinated* individuals than there were to fully vaccinated individuals
  • There were about 14.3 times more lab-confirmed Covid-19 cases to vaccinated individuals than there were to people with prior infection
  • There were about 38.5 times more lab-confirmed Covid-19 cases to unvaccinated or not fully vaccinated* individuals than there were to people with prior infection

*Caveat: this category must be “unvaccinated or not fully vaccinated individuals” because DHHS defines someone as “unvaccinated” if the person has received only one of two injections or if the person is within two weeks of receiving the second injection. So some unknown proportion of cases has occurred to people in definitional limbo somewhere between the first injection and up to 13 days after receiving the second one.

Jon Sanders / Research Editor and Senior Fellow, Regulatory Studies

Jon Sanders studies regulatory policy, a veritable kudzu of invasive government and unintended consequences. As director of regulatory studies at the John Locke Foundation, Jo...