 This study compares the effectiveness of four different COVID-19 vaccines in neutralizing SARS, COV-2 variants of concern, VOCs, in a prospective cohort of 165 healthcare workers in the Netherlands. The results show that mRNA vaccines, BNT162B2 and mRNA-1273, induce higher neutralizing antibody titers against VOCs than adenovirus vector-based vaccines, AZD1222 and AD26.COV2.S. The study also shows that the booster BNT162B2 vaccination increases in neutralizing antibody titers for all groups, with substantial improvement against the VOCs including the Omicron variant. Overall, this study suggests that mRNA vaccines may be more effective in inducing neutralizing antibodies against VOCs than adenovirus vector-based vaccines and could be used for both initial and booster vaccination. This article was authored by Marjay Vangils, Aysha Laville, Karlyn Dander-Stratten and others. We are article.tv, links in the description below.