Fig. 1.

Neutralizing antibody titers against the variants of concern, _{Reciprocal titers of neutralizing antibodies against the Alpha, Beta and Delta lineages in the serum pool of Primary 2 doses of BIBP-CORV vaccine and in the serum pool after booster dose of the same vaccine. t-test was used test the difference in titers between the two vaccine cohorts. The mean titers of BBIBP-CorV two doses cohort against alpha, beta and delta lineages were 138.46 ± 94.68, 34.12 ± 21.52 and 45.78 ± 29.96 repectively, similarly the mean titers of BBIBP-CorV three doses cohort against alpha, beta and delta lineages were 289.23 ±186.30, 103.53 ± 62.94 and 156.89 ± 104.44 respectively}