Hennings and Kanikas study on the new SARS-CoV2 Variant - Omicron - is now online

mRNA booster immunization elicits potent neutralizing serum activity against the SARS-CoV-2 Omicron variant

Henning Gruell#, Kanika Vanshylla#, Pinkus Tober-Lau, David Hillus, PhilippSchommers, Clara Lehmann, Florian Kurth#, Leif E. Sander#, Florian Klein#



The Omicron variant of SARS-CoV-2 is causing a rapid increase in infections in various countries. This new variant of concern carries an unusually high number of mutations in key epitopes of neutralizing antibodies on the spike glycoprotein, suggesting potential immune evasion. Here we assessed serum neutralizing capacity in longitudinal cohorts of vaccinated and convalescent individuals, as well as monoclonal antibody activity against Omicron using pseudovirus neutralization assays. We report a near-complete lack of neutralizing activity against Omicron in polyclonal sera after two doses of the BNT162b2 vaccine, in convalescent individuals, as well as resistance to different monoclonal antibodies in clinical use. However, mRNA booster immunizations in vaccinated and convalescent individuals resulted in a significant increase of serum neutralizing activity against Omicron. Our study demonstrates that booster immunizations will be critical to substantially improve the humoral immune response against the Omicron variant.