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An Improved and High Throughput Respiratory Syncytial Virus RSV Micro-neutralization Assay
Published on: January 26, 2019
mRNA-1273 and BNT162b2 mRNA vaccines have reduced neutralizing activity against the SARS-CoV-2 Omicron variant
Abstract:
The BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines generate potent neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the global emergence of SARS-CoV-2 variants with mutations in the spike protein, the principal antigenic target of these vaccines, has raised concerns over the neutralizing activity of vaccine-induced antibody responses. The Omicron variant, which emerged in November 2021, consists of over 30 mutations within the spike protein. Here, we used an authentic live virus neutralization assay to examine the neutralizing activity of the SARS-CoV-2 Omicron variant against mRNA vaccine-induced antibody responses. Following the 2nd dose, we observed a 30-fold reduction in neutralizing activity against the omicron variant. Through six months after the 2nd dose, none of the sera from naïve vaccinated subjects showed neutralizing activity against the Omicron variant. In contrast, recovered vaccinated individuals showed a 22-fold reduction with more than half of the subjects retaining neutralizing antibody responses. Following a booster shot (3rd dose), we observed a 14-fold reduction in neutralizing activity against the omicron variant and over 90% of boosted subjects showed neutralizing activity against the omicron variant. These findings show that a 3rd dose is required to provide robust neutralizing antibody responses against the Omicron variant.
Insights
mRNA vaccines (BNT162b2, mRNA-1273) showed reduced neutralizing activity against the Omicron variant. A third vaccine dose is necessary for robust antibody responses against SARS-CoV-2 Omicron.
Area of Science:
- Immunology
- Virology
- Vaccinology
Background:
- The emergence of SARS-CoV-2 variants, particularly Omicron with over 30 spike protein mutations, poses a challenge to existing mRNA vaccine-induced neutralizing antibody responses.
- Understanding the impact of these mutations on vaccine efficacy is crucial for public health strategies.
Approach:
- An authentic live virus neutralization assay was employed to assess the neutralizing activity of sera from individuals vaccinated with BNT162b2 or mRNA-1273 against the SARS-CoV-2 Omicron variant.
- Evaluations were conducted after the second vaccine dose, six months post-second dose, and after a third booster dose.
Key Points:
- A 30-fold reduction in neutralizing activity against Omicron was observed after the second vaccine dose.
- Six months after the second dose, no neutralizing activity was detected in sera from naive vaccinated subjects against Omicron.
- Recovered vaccinated individuals showed a 22-fold reduction, with over half retaining neutralizing antibodies.
- Following a third dose, a 14-fold reduction in neutralizing activity was noted, with over 90% of boosted subjects showing response.
Conclusions:
- The SARS-CoV-2 Omicron variant significantly reduces the neutralizing activity of antibodies induced by two doses of mRNA vaccines.
- A third vaccine dose is essential to restore robust neutralizing antibody responses against the Omicron variant.
- These findings underscore the importance of booster vaccinations in maintaining protection against evolving SARS-CoV-2 variants.
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