Related Experiment Video
Updated: Jun 21, 2025
Author Spotlight: Advancing Immune Monitoring in Critical Care Patients Using Whole Blood Assays
Published on: September 20, 2024
Immunogenicity, reactogenicity, and safety of a second booster with BNT162b2 or full-dose mRNA-1273: A randomized
Jannik Stemler1, Lusine Yeghiazaryan2, Christoph Stephan3
1University of Cologne, Institute of Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany; University of Cologne, Faculty of Medicine, and University Hospital Cologne, Department I of Internal Medicine, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD) and Excellence Center for Medical Mycology (ECMM), Cologne, Germany; German Centre for Infection Research (DZIF), Partner Site Bonn Cologne Department, Cologne, Germany.
Objectives:
To assess the safety and immunogenicity of a fourth vaccination (second booster) in individuals aged ≥75 years.
Methods:
Participants were randomized to BNT162b2 (Comirnaty, 30 µg) or messenger RNA (mRNA)-1273 (Spikevax, 100 µg). The primary end point was the rate of two-fold antibody titer increase 14 days after vaccination, targeting the receptor binding domain (RBD) region of wild-type SARS-CoV-2. The secondary end points included changes in neutralizing activity against wild-type and 25 variants. Safety was assessed by monitoring solicited adverse events (AEs) for 7 days.
Results:
A total of 269 participants (mean age 81 years, mRNA-1273 n = 135/BNT162b2 n = 134) were included. Two-fold anti-RBD immunoglobulin (Ig) G titer increase was achieved by 101 of 129 (78%) and 116 of 133 (87%) subjects in the BNT162b2 and the mRNA-1273 group, respectively (P = 0.054). A second booster of mRNA-1273 provided higher anti-RBD IgG geometric mean titer: 21.326 IU/mL (95% confidence interval: 18.235-24.940) vs BNT162b2: 15.181 IU/mL (95% confidence interval: 13.172-17.497). A higher neutralizing activity was noted for the mRNA-1273 group. The most frequent AE was pain at the injection site (51% in mRNA-1273 and 48% in BNT162b2). Participants in the mRNA-1273 group had less vaccine-related AEs (30% vs 39%).
Conclusions:
A second booster of either BNT162b2 or mRNA-1273 provided substantial IgG increase. Full-dose mRNA-1273 provided higher IgG levels and neutralizing capacity against SARS-CoV-2, with similar safety profile for subjects of advanced age.
Related Concept Videos
01:51Vaccinations
01:23Immunological Memory
What is Immunological Memory?
Immunological memory is an integral function of the immune system that allows it to recognize and react more rapidly and effectively to pathogens previously encountered. This feature...
01:26Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and...
00:42Cross-reactivity
01:24B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...