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Coronaviruses

Reduced Neutralizing Activity Against Omicron Variant Observed in mRNA-Vaccinated Individuals

Strategic Insights

— 1 min read

According to a new study published in Cell Reports Medicine, researchers at Emory University have found that mRNA-vaccinated individuals have significantly reduced neutralizing activity against the SARS-CoV-2 omicron variant. The study used serum from mRNA-vaccinated individuals to measure neutralizing activity against omicron in a live-virus assay. The research was supported by the NIH National Institute of Allergy & Infectious Diseases (NIAID) and the Oliver S. and Jennie R. Donaldson Charitable Trust, among others.

Key Takeaways:

  • At 2-4 weeks after a primary series of vaccinations, mRNA-vaccinated individuals show a 30-fold reduction in neutralizing activity against omicron.
  • Six months after the initial two-vaccine doses, sera from naive vaccinated subjects show no neutralizing activity against omicron.
  • In contrast, COVID-19-recovered individuals 6 months after receiving the primary series of vaccinations show a 22-fold reduction, with the majority of the subjects retaining neutralizing antibody responses.
  • In naive individuals following a booster shot (third dose), researchers observed a 14-fold reduction in neutralizing activity against omicron, and over 90% of subjects show neutralizing activity.
  • The study concluded that a third dose is required to provide robust neutralizing antibody responses against the omicron variant.

Statistics:

  • 30-fold reduction in neutralizing activity against omicron observed in mRNA-vaccinated individuals 2-4 weeks after primary vaccinations.
  • 22-fold reduction in neutralizing activity against omicron observed in COVID-19-recovered individuals 6 months after primary vaccinations.
  • 14-fold reduction in neutralizing activity against omicron observed in naive individuals following a booster shot (third dose).
  • 90% of naive individuals exhibited neutralizing activity against omicron after receiving the third dose.

Sources:

  • Mrna-1273 and Bnt162b2 Mrna Vaccines Have Reduced Neutralizing Activity Against the Sars-cov-2 Omicron Variant. Cell Reports Medicine, 2022;3(2).
  • NewsRx. Data on COVID-19 Described by Researchers at Emory University (Mrna-1273 and Bnt162b2 Mrna Vaccines Have Reduced Neutralizing Activity Against the Sars-cov-2 Omicron Variant). Medical Letter on the CDC & FDA. April 3, 2022; p 220.

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