Fig 2. Viral-neutralization effects of UB-612 booster vaccination against wild type, Delta, Omicron BA.1 and BA.2 variants.
Viral-neutralizing titers against SARS-CoV-2 wild-type, Delta, Omicron BA.1, and BA.2 variants were investigated during the infection pandemic that BA.1/BA.2 dominated. Serum samples from 41 participants (n = 27 for 18–65 years; n = 14 for 65–85 years) collected at 14 days post-booster were subjected to a live virus or pseudovirus-luciferase neutralization assay. (A) Live virus assay for Wuhan wild type WT vs. Delta for all ages and (B) live virus assay for WT vs. Delta for young adults and the elderly. (C) Pseudovirus assay for WT vs. BA.1 for all ages and (D) Pseudovirus assay WT vs. BA.1 for young adults and the elderly. (E) Pseudovirus assay for WT vs. BA.2 for all ages and (F) Pseudovirus assay WT vs. BA.2 for young adults and the elderly. The 50% viral-neutralizing antibody geometric mean titers (GMT, 95% CI) were measured, VNT50 for live virus and pVNT50. Statistical analysis was performed by the Student’s t-test (ns, p>0.05; ****, p<0.0001). No significant difference is notable between the two age groups in neutralization effect against WT, Delta, BA.1, and BA.2.