A three-dose course of AstraZeneca's Covid-19 vaccine is effective against the Omicron coronavirus variant, the pharmaceutical company said on Thursday, citing data from an Oxford University lab study.

The study, yet to be published in a peer-reviewed medical journal, showed antibody levels against Omicron after the booster shot were higher than antibodies in people who had been infected with and recovered naturally from Covid-19.

After a three-dose course...