As new forms of the coronavirus took middle stage in the course of the COVID-19 pandemic, the chances of creating lengthy COVID dropped. Those that had been vaccinated in opposition to the virus noticed the largest plunge over time.
For each 1,000 unvaccinated individuals, 104 developed lengthy COVID as much as one 12 months after an an infection in the course of the pre-delta part of the pandemic. That fell to 95 per 1,000 in the course of the delta variant’s period and 78 throughout omicron’s reign. Amongst vaccinated individuals, simply 53 out of 1,000 developed lengthy COVID as much as a 12 months after an infection throughout delta and solely 35 throughout omicron, researchers report July 17 within the New England Journal of Medication.
The research of U.S. Division of Veterans Affairs Well being Care System information checked out individuals who had a COVID an infection from March of 2020 — the month the pandemic started — to the top of January in 2022. The researchers, from the Veterans Affairs St. Louis Well being Care System, in contrast the charges of lengthy COVID throughout three phases of the pandemic amongst those that had and had not gotten vaccinated. The first COVID vaccine was launched in December of 2020 (SN: 12/11/20). The delta variant dominated the US in the summertime of 2021, with the omicron variant taking on starting in December 2021 (SN: 7/2/21; SN: 12/21/21).
Falling charges
The speed of lengthy COVID fell because the coronavirus developed in the course of the pandemic, particularly for vaccinated individuals. The evaluation centered on near 450,000 U.S. veterans contaminated with COVID from March 2020 to January 2022.
A comparability of omicron infections with infections from prior eras discovered that 72 p.c of the drop within the lengthy COVID price throughout omicron was attributable to vaccines. The rest was as a result of modifications within the virus and enhancements in medical care and the usage of antiviral therapies in the course of the omicron part.
Even with the steep decline within the incidence of lengthy COVID for vaccinated individuals, there’s nonetheless a danger, the researchers write. With “the massive numbers of ongoing new infections and reinfections, and the poor uptake of vaccination,” they proceed, this “might translate right into a excessive variety of individuals” with lengthy COVID.
