Table 3.
Immune responses by vaccine schedule at weekly timepoints post prime dose in the 28-day prime-boost interval study groups
|
Prime with ChAd |
Prime with BNT |
||||||
|---|---|---|---|---|---|---|---|
| ChAd/ChAd (n=105) | ChAd/BNT (n=108) | p value* | BNT/BNT (n=110) | BNT/ChAd (n=109) | p value* | ||
| SARS-CoV-2 anti-spike IgG | |||||||
| Day 7†‡ | |||||||
| n | 21 | 19 | .. | 23 | 23 | .. | |
| Median, ELU/mL | 25 (25–25) | 25 (25–25) | .. | 25 (25–25) | 25 (25–25) | 0·95 | |
| ≥50·3 ELU/mL | 0 (0%, 0–16) | 0 (0%, 0–18) | >0·99 | 2 (9%, 1–28) | 2 (9%, 1–28) | >0·99 | |
| Day 14† | |||||||
| n | 21 | 19 | .. | 23 | 23 | .. | |
| Geometric mean, ELU/mL | 87 (54–141) | 198 (96–408) | 0·041 | 967 (718–1304) | 735 (495–1092) | 0·39 | |
| ≥50·3 ELU/mL | 14 (67%, 43–85) | 16 (84%, 60–97) | 0·28 | 23 (100%, 85–100) | 23 (100%, 85–100) | >0·99 | |
| Day 28 | |||||||
| n | 105 | 108 | .. | 110 | 109 | .. | |
| Geometric mean, ELU/mL | 501 (394–638) | 613 (485–776) | 0·22 | 1487 (1233–1795) | 1715 (1447–2033) | 0·28 | |
| ≥50·3 ELU/mL | 100 (95%, 89–98) | 104 (96%, 91–99) | 0·75 | 110 (100%, 97–100) | 109 (100%, 97–100) | >0·99 | |
| Day 35† | |||||||
| n | 22 | 20 | .. | 22 | 24 | .. | |
| Geometric mean, ELU/mL | 1151 (825–1605) | 15 365 (11 764–20 068) | <0·0001 | 17011 (12 446–23 248) | 6798 (5060–9133) | <0·0001 | |
| ≥50·3 ELU/mL | 22 (100%, 85–100) | 20 (100%, 83–100) | >0·99 | 22 (100%, 85–100) | 24 (100%, 86–100) | >0·99 | |
| Cellular response | |||||||
| Day 14† | |||||||
| n | 21 | 19 | .. | 23 | 23 | .. | |
| Geometric mean, SFC per million PBMCs | 182 (133–251) | 136 (83–223) | 0·21 | 37 (17–64) | 32 (20–51) | 0·92 | |
| ≥4 SFC per million PBMCs | 21 (100%, 84–100) | 19 (100%, 82–100) | >0·99 | 22 (96%, 78–100) | 23 (100%, 85–100) | >0·99 | |
| ≥24 SFC per million PBMCs | 21 (100%, 84–100) | 17 (89%, 67–99) | 0·22 | 12 (52%, 31–73) | 12 (52%, 31–73) | >0·99 | |
| Day 28 | |||||||
| n | 103 | 107 | .. | 109 | 108 | .. | |
| Geometric mean, SFC per million PBMCs | 53 (41–69) | 52 (41–66) | 0·98 | 15 (12–18) | 16 (13–20) | 0·81 | |
| ≥4 SFC per million PBMCs | 101 (98%, 93–100) | 107 (100%, 97–100) | 0·24 | 101 (93%, 86–97) | 97 (90%, 83–95) | 0·48 | |
| ≥24 SFC per million PBMCs | 74 (72%, 62–80) | 75 (70%, 60–79) | 0·88 | 34 (31%, 23–41) | 35, (32%, 24–42) | 0·88 | |
| Day 42† | |||||||
| n | 22 | 18 | .. | 22 | 23 | .. | |
| Geometric mean, SFC per million PBMCs | 97 (60–157) | 375 (266–528) | 0·0022 | 135 (83–219) | 130 (69–243) | 0·87 | |
| ≥4 SFC per million PBMCs | 22 (100%, 85–100) | 18 (100%, 81–100) | >0·99 | 22 (100%, 85–100) | 22 (96%, 78–100) | >0·99 | |
| ≥24 SFC per million PBMCs | 19 (86%, 65–97) | 18 (100%, 81–100) | 0·24 | 19 (86%, 65–97) | 20 (87%, 66–97) | >0·99 | |
Data shown are geometric mean (95% CI) for continuous variables, and n (%, 95% CI) for binary variables, unless otherwise indicated; 50·3 ELU/mL was the LLOQ for SARS-CoV-2 anti-spike IgG; 4 SFC per million PBMCs was the LLOD and 24 SFC per million PBMCs was the LLOQ for cellular response. ChAd=ChAdOx1 nCoV-19 vaccine, AstraZeneca. BNT=BNT162b2 vaccine, Pfizer–BioNTech. ELU=ELISA laboratory units. SFC=spot-forming units. PBMC=peripheral blood mononuclear cell. LLOQ=lower limit of quantification. LLOD=lower limit of detection.
For continuous variables, p values were reported using linear regression model adjusting for age, sex, study site, and cohort (where applicable); Fisher's exact test was used to report p values for binary variables.
Immunology cohort only.
Data shown are median (IQR) due to a high proportion of censored data; p values were reported using Mann-Whitney U test.