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 (NT 50 ) 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 earlier timepoints. Moderna results were similar to Pfizer at 2 weeks after the second dose, while the titres for AstraZeneca samples derived from older donors were 7-fold lower against VIC31 and below the limit of detection against Delta and Omicron. Age and gender were not found to significantly impact our results. These findings indicate that vaccine matching may be needed, and that at least a third dose of these vaccines is necessary to generate sufficient neutralising antibodies against emerging variants of concern, especially Omicron, amidst the challenges of ensuring vaccine equity worldwide.
Keywords: AlphaFold; COVID-19; SARS-CoV-2; biomolecular modelling; neutralising antibody titres; spike protein; vaccines; variants of concern.
【저자키워드】 COVID-19, SARS-CoV-2, Vaccines, Spike protein, biomolecular modelling, variants of concern., AlphaFold, neutralising antibody titres, 【초록키워드】 coronavirus disease, Vaccine, Neutralising Antibodies, variants of concern, Delta, Gender, omicron, Omicron variants, variants, Spike protein, Pfizer, Coronavirus disease-19, neutralising antibody, limit of detection, donors, neutralisation, AstraZeneca, Moderna, Donor, dose, neutralising antibody titres, equity, followed by, Older, titres, second dose, different time points, plasma samples, titre, timepoints, virus neutralization assays, significantly, generate, reduction in, different time point, neutralizing antibody titre, virus neutralization assay, were assessed, 【제목키워드】 leading, Essential,