Table 2.
SARS-CoV-2 neutralizing antibody titers (PRNT50 assay) against ancestral (Wuhan) virus at Days 0 and 42, and Omicron sub-lineages BA.5 at Days 0 and 42, two weeks after the second vaccination with intranasal BBV154 or intramuscular Covaxin.
| GMT ratio (BBV154:Covaxin) | |||||||
|---|---|---|---|---|---|---|---|
| Vaccine | n | GMT | (95% CI) | GMFR | Ratio | (95% CI) p value | |
| Ancestral (Wuhan) virus – whole population | |||||||
| Day 0 | BBV154 | 481 | 26.1 | (18.7‒36.6) | – | 0.7 |
(0.04‒1.37) p = 0.30 |
| Covaxin | 159 | 37.0 | (20.9‒65.4) | – | |||
| Day 42 | BBV154 | 481 | 768.5 | (665.1‒888.0) | 29.4 | 1.5 |
(1.11‒1.88) p = 0.006 |
| Covaxin | 159 | 531.0 | (425.9‒662.1) | 14.4 | |||
| Ancestral (Wuhan) virus – seronegative at Day 0 | |||||||
| Day 0 | BBV154 | 138 | 0.09 | (0.09‒0.09) | |||
| Covaxin | 39 | 0.09 | (0.09‒0.16) | ||||
| Day 42 | BBV154 | 138 | 471.1 | (300.0‒739.7) | 5234 | 1.4 |
(0.61–3.12) p = 0.43 |
| Covaxin | 39 | 340.6 | (171.5‒676.2) | 3784 | |||
| Omicron BA.5 | |||||||
| Day 0 | BBV154 | 159 | 10.2 | (6.1‒17.1) | 2.4 |
(0.72–8.06) p = 0.15 |
|
| Covaxin | 50 | 4.2 | (1.4‒12.6) | ||||
| Day 42 | BBV154 | 161 | 170.8 | (137‒213) | 16.7 | 2.1 | (1.18–3.64) |
| Covaxin | 50 | 82.4 | (48.9‒139) | 19.6 | p = 0.02 | ||
Neutralizing responses expressed as PRNT50 (reciprocal of dilution achieving 50% neutralization).
Superiority was concluded if either the lower limit of the two-sided 95% CI for the ratio of GMTs (BBV154 GMT: Covaxin® GMT) was ≥1.0.
GMFR geometric mean-fold rise from baseline to Day 42.