Covid immunity lasts at least a year after infection plus shots: Study

People who have been both previously infected and vaccinated against Covid-19 get long-lasting protection against severe disease and hospitalization, a large international study found.

The combination prevented more than 97 per cent of severe disease or hospitalization for up to 12 months after infection or initial immunization, whichever was most recent, according to a report from the World Health Organization. Boosters conferred an additional 6 months of protection. Meanwhile, infection alone was just under 75 per cent protective over a year.  

The report was based on a review of more than two dozen studies from January 2020 to