Preliminary findings from a study suggest that infection with the Omicron variant of coronavirus could boost a person’s immunity against the more severe Delta variant.

South African scientists at the Africa Health Research Institute in Durban examined 33 unvaccinated and vaccinated individuals who had contracted the Omicron variant, Reuters reported. They found that people who were infected with Omicron developed enhanced immunity to the Delta variant. Their immunity was even stronger if they had previously been vaccinated against COVID-19.

The study, which has not yet been peer-reviewed, also finds that Omicron could displace Delta as the dominant coronavirus variant.