by Jon Sanders
Research Editor and Senior Fellow, Regulatory Studies, John Locke Foundation
Note: I noticed yesterday that the NC Office of State Budget and Management had on February 18 updated the July 2021 population estimate I have been using (10,753,496). I am now using the new population estimate of 10,658,717.
Here is the NC Threat-Free Index for the week ending March 21:
DHHS lists that as of March 22, 28% of the state population 18+ year of age has been at least partially vaccinated, and that 17.8% of this population has been fully vaccinated. I don’t know how much overlap there is between recoveries and vaccinations. If people who have recovered from the virus (i.e., a natural vaccination) were a completely separate population from those who have been vaccinated, that would suggest that as of March 22, just over 24.2% of the state population was immune.
Even that statistic would likely be vastly undercounting state immunity, given how many mild infections (never diagnosed), exposures fought off due to preexisting immunity, and SARS-CoV-2 infections that people had prior to the virus being officially identified (diagnosed as influenza-like illnesses) there must have been.
With respect to immunity via previous SARS-CoV-2 infections and vaccinations, newly published research (March 19, 2021) in the Journal of the American Medical Association confirms expectations: antibodies from recovering from an infection and from the vaccine not only rapidly appear and persist for months and months, but also they ward off virus infections from new variants. Here’s the main finding:
This study found neutralizing activity of infection- and vaccine-elicited antibodies against 4 SARS-CoV-2 variants, including B.1, B.1.1.7, and N501Y. Because neutralization studies measure the ability of antibodies to block virus infection, these results suggest that infection- and vaccine-induced immunity may be retained against the B.1.1.7 variant. As additional variants emerge, neutralizing-antibody responses after infection and vaccination should be monitored.