Journal article

At Least Three Doses of Leading Vaccines Essential for Neutralisation of SARS-CoV-2 Omicron Variant

NB Singanallur, PJ van Vuren, AJ McAuley, MP Bruce, MJ Kuiper, SM Gwini, S Riddell, S Goldie, TW Drew, KR Blasdell, M Tachedjian, S Mangalaganesh, S Chahal, L Caly, JD Druce, JA Juno, SJ Kent, AK Wheatley, SS Vasan

Frontiers in Immunology | Published : 2022

Abstract

Plasma samples taken at different time points from donors who received either AstraZeneca (Vaxzevria) or Pfizer (Comirnaty) or Moderna (Spikevax) coronavirus disease-19 (COVID-19) vaccine were assessed in virus neutralization assays against Delta and Omicron variants of concern and a reference isolate (VIC31). With the Pfizer vaccine there was 6-8-fold reduction in 50% neutralizing antibody titres (NT50) against Delta and VIC31 at 6 months compared to 2 weeks after the second dose; followed by 25-fold increase at 2 weeks after the third dose. Neutralisation of Omicron was only consistently observed 2 weeks after the third dose, with most samples having titres below the limit of detection at ..

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Grants

Awarded by Alexander von Humboldt-Stiftung


Funding Acknowledgements

This work was supported by funding (Principal Investigator: SV) from the CSIRO's Precision Health & Responsible Innovation Future Science Platforms, National Health and Medical Research Council (grant MRF2009092), and United States Food and Drug Administration (FDA) Medical Countermeasures Initiative (contract 75F40121C00144). JJ, SK, and AW are grateful to the National Health and Medical Research Council (for grants GNT2002073, MRF2005544, GNT1149990, fellowships and an investigator grant). We also thank the Victorian Government, especially the Victorian Department of Health and Human Services, the major funder of the Victorian Infectious Diseases Reference Laboratory and Barwon Health. The article reflects the views of the authors and does not represent the views or policies of the funding agencies including the FDA.