Sinovac's two-dose Covid-19 vaccine followed by a booster Pfizer-BioNTech shot showed a lower immune response against the Omicron variant compared with other strains, according to a study by researchers.

The study, which has not been peer-reviewed yet, was conducted by researchers from Yale University, the Dominican Republic's Ministry of Health and other institutions.

The Sinovac two-dose regimen along with the Pfizer shot produced an antibody response similar to a two-dose mRNA vaccine, according to the study...