Table 4.
Mean vaccine effectiveness against infection for rounds 13 and 14* of REACT-1
|
Test negatives (%) |
Test positives (%) |
Vaccine effectiveness (95% CI) | Interaction p value† | |||||
|---|---|---|---|---|---|---|---|---|
| Round 13 | Round 14 | Total | Round 13 | Round 14 | Total | |||
| Full population | ||||||||
| Unvaccinated | 2907 (73·9%) | 1026 (26·1%) | 3933 | 44 (77·2%) | 13 (22·8%) | 57 | ·· | ·· |
| All vaccines | ||||||||
| Round | 34 853 (41·2%) | 49 688 (58·8%) | 84 541 | 144 (30·5%) | 328 (69·5%) | 472 | 66·3% (55·3–74·7) | 0·05 |
| Round, age, and sex | 34 853 (41·2%) | 49 688 (58·8%) | 84 541 | 144 (30·5%) | 328 (69·5%) | 472 | 61·4% (47·5–71·6) | 0·11 |
| Round, age, sex, IMD, region, and ethnicity | 34 853 (41·2%) | 49 688 (58·8%) | 84 541 | 144 (30·5%) | 328 (69·5%) | 472 | 62·8% (49·3–72·7) | 0·09 |
| AstraZeneca vaccine | ||||||||
| Round | 24 934 (44·3%) | 31 290 (55·7%) | 56 224 | 109 (30·5%) | 248 (69·5%) | 357 | 62·3% (49·7–71·8) | 0·02 |
| Round, age, and sex | 24 934 (44·3%) | 31 290 (55·7%) | 56 224 | 109 (30·5%) | 248 (69·5%) | 357 | 41·8% (18·5–58·4) | 0·13 |
| Round, age, sex, IMD, region, and ethnicity | 24 934 (44·3%) | 31 290 (55·7%) | 56 224 | 109 (30·5%) | 248 (69·5%) | 357 | 44·8% (22·5–60·7) | 0·11 |
| Pfizer–BioNTech vaccine | ||||||||
| Round | 6500 (33·5%) | 12 888 (66·5%) | 19 388 | 26 (31·7%) | 56 (68·3%) | 82 | 70·7% (57·5–79·7) | 0·51 |
| Round, age, and sex | 6500 (33·5%) | 12 888 (66·5%) | 19 388 | 26 (31·7%) | 56 (68·3%) | 82 | 70·0% (55·0–80·0) | 0·56 |
| Round, age, sex, IMD, region, and ethnicity | 6500 (33·5%) | 12 888 (66·5%) | 19 388 | 26 (31·7%) | 56 (68·3%) | 82 | 71·3% (56·6–81·0) | 0·49 |
| Moderna vaccine | ||||||||
| Round | 24 (2%) | 1 197 (98·0%) | 1 221 | 0 (0·0%) | 4 (100·0%) | 4 | 74·4% (21·9–91·6) | 0·98 |
| Round, age, and sex | 24 (2%) | 1 197 (98·0%) | 1 221 | 0 (0·0%) | 4 (100·0%) | 4 | 76·4% (27·6–92·3) | 0·98 |
| Round, age, sex, IMD, region, and ethnicity | 24 (2%) | 1 197 (98·0%) | 1 221 | 0 (0·0%) | 4 (100·0%) | 4 | 75·1% (22·7–92·0) | 0·98 |
| Unknown | ||||||||
| Round | 3395 (44·0%) | 4313 (56·0%) | 7 708 | 9 (31·0%) | 20 (69·0%) | 29 | 74·9% (59·8–84·3) | 0·15 |
| Round, age, and sex | 3395 (44·0%) | 4313 (56·0%) | 7 708 | 9 (31·0%) | 20 (69·0%) | 29 | 68·1% (46·6–81·0) | 0·28 |
| Round, age, sex, IMD, region, and ethnicity | 3395 (44·0%) | 4313 (56·0%) | 7 708 | 9 (31·0%) | 20 (69·0%) | 29 | 67·1% (44·1–80·6) | 0·16 |
| Symptomatic positives only‡ | ||||||||
| Unvaccinated | 2907 (73·9%) | 1026 (26·1%) | 3 933 | 44 (77·2%) | 13 (22·8%) | 77 | ·· | ·· |
| All vaccines | ||||||||
| Round | 34 853 (41·2%) | 49 688 (58·8%) | 84 541 | 64 (22·2%) | 224 (77·8%) | 288 | 67·8% (53·0–77·9) | 0·03 |
| Round, age, and sex | 34 853 (41·2%) | 49 688 (58·8%) | 84 541 | 64 (22·2%) | 224 (77·8%) | 288 | 64·4% (46·8–76·2) | 0·04 |
| Round, age, sex, IMD, region, and ethnicity | 34 853 (41·2%) | 49 688 (58·8%) | 84 541 | 64 (22·2%) | 224 (77·8%) | 288 | 66·4% (49·6–77·6) | 0·04 |
| AstraZeneca vaccine | ||||||||
| Round | 24 934 (44·3%) | 31 290 (55·7%) | 56 224 | 49 (21·7%) | 177 (78·3%) | 226 | 62·3% (44·9–74·3) | 0·01 |
| Round, age, and sex | 24 934 (44·3%) | 31 290 (55·7%) | 56 224 | 49 (21·7%) | 177 (78·3%) | 226 | 42·4% (11·0–62·7) | 0·05 |
| Round, age, sex, IMD, region, and ethnicity | 24 934 (44·3%) | 31 290 (55·7%) | 56 224 | 49 (21·7%) | 177 (78·3%) | 226 | 45·5% (15·5–64·9) | 0·06 |
| Pfizer–BioNTech vaccine | ||||||||
| Round | 6500 (33·5%) | 12 888 (66·5%) | 19 388 | 9 (21·4%) | 33 (78·6%) | 42 | 76·5% (61·1–85·8) | 0·23 |
| Round, age, and sex | 6500 (33·5%) | 12 888 (66·5%) | 19 388 | 9 (21·4%) | 33 (78·6%) | 42 | 74·2% (55·4–85·1) | 0·34 |
| Round, age, sex, IMD, region, and ethnicity | 6500 (33·5%) | 12 888 (66·5%) | 19 388 | 9 (21·4%) | 33 (78·6%) | 42 | 76·6% (59·0–86·6) | 0·32 |
| Moderna vaccine§ | ||||||||
| Round | 24 (2%) | 1197 (98%) | 1 221 | 0 | 0 | 0 | ·· | ·· |
| Unknown | ||||||||
| Round | 3395 (44·0%) | 4313 (56·0%) | 7708 | 6 (30·0%) | 14 (70·0%) | 20 | 70·2% (46·3–83·4) | 0·30 |
| Round, age, and sex | 3395 (44·0%) | 4313 (56·0%) | 7708 | 6 (30·0%) | 14 (70·0%) | 20 | 59·9% (23·2–79·1) | 0·53 |
| Round, age, sex, IMD, region, and ethnicity | 3395 (44·0%) | 4313 (56·0%) | 7708 | 6 (30·0%) | 14 (70·0%) | 20 | 61·1% (23·7–80·2) | 0·36 |
Data are means (95% CIs), and adjusted for round and further adjusted for age and sex, and index of multiple deprivation (IMD), region, and ethnicity for participants aged 18–64 years and those reporting at least one symptom in month before swabbing.
Of the participants aged 18–64 years with valid swabs from round 13 (n=57 457) and round 14 (59 655), 49 923 consented to have their data linked in round 13, as did 52 219 in round 14.
p value for the multiplicative interaction term assessing possible modification of the effect of vaccination status by round.
Symptomatic positive individuals are defined as those with a positive swab having reported at least one of 29 surveyed symptoms in the month before swabbing.
No symptomatic positive swab was observed in rounds 13 and 14; we therefore did not calculate vaccine effectiveness in this instance.