Natural Immunity Protects Against Severe Infection Throughout Pandemic

Study Indicates Prior Infection, Milder Strains were Protective while Vaccination Backfired and Increased Risk of Hospitalization

By Peter A. McCullough, MD, MPH

When a patient called from from 2022 forward with a new episode of COVID-19, the first thing I asked them was “have you had COVID-19 in the past?” This is such an important question because that natural immunity has been powerful in mitigating risks of future COVID-19 hospitalization.

Uuskula et al leveraged a nationwide database in Estonia to give critical information on the changing waves of COVID-19 infection:

“Vaccination in Estonia began in January 2021, with a cumulative vaccination uptake about 70% among adult population by June 2022. Within the time period of data underlying the present study, Estonia had three large pandemic waves: the first was from March to June 2020 (SARS-CoV-2 pre-variant of concern era); the second was from November 2020 to May 2021 (first the Alpha variant, then the Delta variant); and the third was from December 2022 (Omicron variant). Our analysis used data derived from the nationwide and population-based universal tax-funded Estonian health care system. We conducted a retrospective cohort study (N=329,496 adults which allowed 246,113 individuals being matched into the three cohorts) based on linking individual-level data on laboratory-confirmed COVID-19, SARS-CoV-2 vaccination status, and health care utilization between 26 February 2020 and 23 February 2022 from the national e-health records.”