Preliminary data from a study conducted at the University of Oxford indicates that the Covid-19 vaccine developed by AstraZeneca PLC is effective against the P1, or Brazilian, variant, a source with knowledge of the study told Reuters yesterday. The data indicates that the vaccine will not need to be modified in order to protect against the variant, which is believed to have originated in the Amazonian city of Manaus, said the source. The source did not provide the exact efficacy of the vaccine against the variant. They said the full results of the study should be released soon, possibly in March. Early results indicated the AstraZeneca vaccine was less effective against the South African variant, which is similar to P1. South Africa subsequently paused the use of the vaccine in the country.