Vaccination- and/or natural infection-induced immune responses against SARS-CoV-2 Omicron subvariants biorxivpreprint immune SARSCoV2 vaccination immunity COVID19 coronavirus covid
By Pooja Toshniwal PahariaOct 27 2022Reviewed by Danielle Ellis, B.Sc. In a recent study posted to the bioRxiv* preprint server, researchers comparatively evaluated the neutralization antibody titers for severe acute respiratory syndrome coronavirus 2 Omicron VOC subvariants BA.1, BA.2, BA.4/5 among individuals with ancestral B.1 strain infections, vaccinated individuals, or with hybrid immunity from breakthrough infections and vaccinations with Delta or Gamma VOCs.
The team compared the neutralization ability of sera obtained from 58 unvaccinated and D614G-infected coronavirus disease 2019 patients , 14 booster-vaccinated individuals, and 16 vaccinated and Delta-infected or Gamma-infected BTI patients against D614G, Delta and Omicron BA.1, BA.2, BA.4/5 strains.
Nasopharyngeal swabs were obtained from the participants for virological assays, and next-generation sequencing was performed. To evaluate SARS-CoV-2 VOC and sub-VOC neutralization, live virus neutralization assays and human immunodeficiency virus pseudotype-based neutralization assays were performed. The 50% tissue culture infectious dose , the half-maximal inhibitory concentration , and the 50% neutralizing titer values were determined.
Moderate COVID-19 convalescents showed better neutralization responses. BA.1 and BA.2 showed the greatest resistance and sensitivity, respectively, against all sera. Omicron BA.5 escaped neutralization responses of vaccinated individuals better than natural infection-induced and hybrid immunity-induced responses.