Related Experiment Video
Updated: Jul 8, 2025
Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity
Published on: June 25, 2015
Long-term immune response to Omicron-specific mRNA vaccination in mice, hamsters, and nonhuman primates
Yi Wu1,2, Namei Wu1, Xiaoying Jia3
1Department of Laboratory Medicine The First Affiliated Hospital of USTC Division of Life Sciences and Medicine University of Science and Technology of China Hefei Anhui P. R. China.
Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron and its subvariants (such as BQ.1, XBB and the latest variants, including XBB.1.16, EG.5, and BA.2.86), as the dominant variants, currently account for almost all new infections in the world due to their high transmissibility and immune escape ability. Omicron-specific mRNA vaccines showed great potential to protect against Omicron infections. However, whether the vaccine could provide long-term protection is unknown. Toward this goal, we evaluated the immunogenicity of a preclinical Omicron (BA.1)-specific mRNA vaccine (SOmicron-6P) in different animal models. SOmicron-6P induced the highest levels of antibody titers at 1-2 weeks in different animals after the second dose. Even 9 months after the immunization, we observed modest neutralizing activity against Omicron subvariants in macaques. In addition, immunological memory cells can be rapidly reactivated upon stimulation. SOmicron-6P at concentrations higher than 10 μg effectively protected hamsters from BA.1 challenge 253 days after the first immunization, which could be attributed to the reactivation of immune systems. In addition, the toxicity tests conducted in rats revealed a highly favorable biosafety profile for SOmicron-6P, even at high dosages. Our data suggest that the Omicron-specific mRNA vaccine is highly effective and safe in animal models and provides long-term immunologic protection against SARS-CoV-2 Omicron infections.
Insights
An Omicron-specific mRNA vaccine demonstrated long-term protection against SARS-CoV-2 Omicron variants in animal models. The vaccine was found to be safe and effective, inducing robust immune responses and memory cell reactivation.
Area of Science:
- Immunology
- Vaccinology
- Virology
Background:
- Omicron and its subvariants are dominant SARS-CoV-2 strains due to high transmissibility and immune evasion.
- Omicron-specific mRNA vaccines show promise, but long-term protection remains unevaluated.
Purpose of the Study:
- To assess the immunogenicity and long-term protective efficacy of a preclinical Omicron (BA.1)-specific mRNA vaccine (SOmicron-6P).
Main Methods:
- Evaluated SOmicron-6P in various animal models (mice, hamsters, macaques).
- Assessed antibody titers, neutralizing activity, immunological memory, protection against viral challenge, and biosafety.
- Measured immune responses at different time points post-vaccination.
Main Results:
- SOmicron-6P induced peak antibody titers 1-2 weeks after the second dose.
- Modest neutralizing activity against Omicron subvariants persisted for 9 months in macaques.
- Effective protection against BA.1 challenge was observed in hamsters 253 days post-immunization, linked to immune system reactivation.
- Toxicity tests in rats showed a favorable biosafety profile, even at high doses.
Conclusions:
- The Omicron-specific mRNA vaccine (SOmicron-6P) is highly effective and safe in preclinical animal models.
- The vaccine provides sustained immunologic protection against SARS-CoV-2 Omicron infections, likely through immune memory.
- Further investigation into long-term efficacy and human application is warranted.
More Related Videos
11:07Whole-animal Imaging and Flow Cytometric Techniques for Analysis of Antigen-specific CD8+ T Cell Responses after Nanoparticle Vaccination
Published on: April 29, 2015
08:15In Vitro Cellular Activity Evaluation of the Nanoemulsion Vaccine Adjuvant Ophiopogonin D
Published on: December 9, 2022
