People who have been infected with a pre-Omicron variant of COVID-19 have high protection against hospitalizations caused by the Omicron variant, according to a study published last Friday.
The study carried out last winter by a team from the National Institute of Public Health of Quebec (INSPQ), Laval University and other research establishments in Canada adds that in unvaccinated people, a pre -Omicron reduces the risk of infection from Omicron by 44% and lowers the risk of hospitalization from Omicron by 81%.
Protection is higher in people who have been vaccinated. Indeed, the combination of pre-Omicron infection and vaccination provides the highest protection against hospitalizations: 86% with one dose, 94% with two doses and 97% with three doses.
The study also observed that the protection conferred against Omicron by a previous infection decreases over time.
The leader of the study, Gaston De Serres, professor at Laval University and chief physician of the scientific group in immunization at the INSPQ, reports that vaccinated people who have not been infected with the virus have less durable protection. against the risk of hospitalization. If they are 60 or older or have a chronic illness, it is important that they receive the prescribed booster doses, in his opinion.
Dr. De Serres adds in an article published by Laval University that if future studies show that a previous infection protects well against the main variant now circulating in Quebec, the recommendations could be revised to take into account the protective effect. caused by a COVID-19 infection.
The study involved nearly 697,000 people aged 12 and over; it was conducted between December 26 and March 12.
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