Table 2.
Immune responses by vaccine schedule at 28 days post boost dose (56 days post prime) in the 28-day prime-boost interval study groups
|
Prime with ChAd |
Prime with BNT |
||||||
|---|---|---|---|---|---|---|---|
| ChAd/ChAd | ChAd/BNT | GMR* | BNT/BNT | BNT/ChAd | GMR* | ||
| Per-protocol analysis | |||||||
| N | 104 | 104 | .. | 109 | 109 | .. | |
| SARS-CoV-2 anti-spike IgG, ELU/mL | 1392 (1188 to 1630) | 12 906 (11 404 to 14 604) | 9·2 (97·5% CI 7·5 to ∞) | 14 080 (12 491 to 15 871) | 7133 (6415 to 7932) | 0·51 (97·5% CI 0·43 to ∞) | |
| Modified intention-to-treat analysis | |||||||
| N | 105 | 108 | .. | 110 | 109 | .. | |
| SARS-CoV-2 anti-spike IgG | |||||||
| n | 105 | 108 | .. | 110 | 109 | .. | |
| Concentration, ELU/mL | 1387 (1186 to 1623) | 12 995 (11 520 to 14 660) | 9·3 (95% CI 7·7 to 11·4) | 13 938 (12 358 to 15 719) | 7133 (6415 to 7932) | 0·51 (95% CI 0·44 to 0·60) | |
| Live virus neutralising antibody | |||||||
| n | 98 | 104 | .. | .. | .. | .. | |
| Normalised NT50 | 201 (171 to 235) | 1269 (1107 to 1454) | 6·4 (95% CI 5·2 to 7·8) | .. | .. | .. | |
| Pseudotype virus neutralising antibody | |||||||
| n | 101 | 101 | .. | 102 | 104 | .. | |
| NT50 | 61 (50 to 73) | 515 (430 to 617) | 8·5 (95% CI 6·5 to 11·0) | 574 (475 to 694) | 383 (317 to 463) | 0·67 (95% CI 0·51 to 0·88) | |
| Cellular response | |||||||
| n | 104 | 108 | .. | 110 | 109 | .. | |
| SFC per million PBMCs | 48 (37 to 61) | 184 (152 to 223) | 3·9 (95% CI 2·9 to 5·3) | 80 (63 to 101) | 97 (76 to 125) | 1·2 (95% CI 0·87 to 1·7) | |
Data shown are geometric mean (95% CI) for continuous variables. ChAd=ChAdOx1 nCoV-19 vaccine, AstraZeneca. BNT=BNT162b2 vaccine, Pfizer–BioNTech. GMR=geometric mean ratio. ELU=ELISA laboratory units. NT50=50% neutralising antibody titre. SFC=spot-forming units. PBMC=peripheral blood mononuclear cell.
*
GMRs were adjusted for randomisation stratification variables, including study site and cohort, with one-sided 97·5% CIs in per-protocol analyses and two-sided 95% CIs in the modified intention-to-treat analyses; the non-inferiority margin was 0·63.