Having two doses of a COVID-19 vaccine has been linked with negative protection against the disease, scientists say, while a previous infection without vaccination offers around 50 percent immunity, according to a study analyzing the Omicron wave in Qatar.
The study, published in the New England Journal of Medicine on June 15, examined the Omicron wave in Qatar that occurred from around December 2021 to February 2022, comparing vaccination rates and immunity among more than 100,000 Omicron infected and non-infected individuals.
The authors of the study found that those who had a prior infection but no vaccination had a 46.1 and 50 percent immunity against the two subvariants of the Omicron variant, even at an interval of more than 300 days since the previous infection….