High effectiveness of mix-and-match COVID-19 vaccines

People who had received a first dose of the Oxford-AstraZeneca COVID-19 vaccine and received an mRNA vaccine for their second dose had a lower risk of infection compared to people who had received both doses of the Oxford-AstraZeneca vaccine. This is shown in a nationwide study performed by researchers at Umeå University, Sweden.

source https://medicalxpress.com/news/2021-10-high-effectiveness-mix-and-match-covid-vaccines.html