Table 2.
Predictors of positive IgG, IgA, and neutralising antibodies following vaccination
|
Total positive IgG*(week 3†; n=698) |
Total positive neutralisation*(week 3†; n=261)‡ |
Total positive IgA*(week 4†; n=324)‡ |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Number of individuals assessed (%) | Odds ratio (95% CI) | p value | Number of individuals assessed (%) | Odds ratio (95% CI) | p value | Number of individuals assessed (%) | Odds ratio (95% CI) | p value | ||
| Sex | ||||||||||
| Female | 552 (78%) | 1 (ref) | .. | 215 (79%) | 1 (ref) | .. | 259 (79%) | 1 (ref) | .. | |
| Male | 146 (22%) | 0·65 (0·38–1·11) | 0·115 | 46 (22%) | 0·57 (0·31–1·04) | 0·066 | 65 (21%) | 0·78 (0·38–1·61) | 0·497 | |
| Age (years) | ||||||||||
| 18–45·99 | 324 (43%) | 1 (ref) | <0·0001§ | 133 (44%) | 1 (ref) | <0·0001§ | 150 (42%) | 1 (ref) | 0·0108§ | |
| 46–65·99 | 332 (49%) | 0·17 (0·09–0·34) | <0·0001 | 105 (41%) | 0·47 (0·27–0·83) | 0·009 | 120 (39%) | 0·33 (0·15–0·72) | 0·006 | |
| ≥66 | 42 (8%) | 0·06 (0·02–0·14) | <0·0001 | 23 (15%) | 0·16 (0·08–0·35) | <0·0001 | 54 (19%) | 0·28 (0·11–0·72) | 0·008 | |
| BMI (kg/m2) | ||||||||||
| <25 | 396 (55%) | 1 (ref) | 0·1986§ | 155 (57%) | 1 (ref) | 0·4600§ | 192 (57%) | 1 (ref) | 0·3892§ | |
| 25–29·99 | 195 (30%) | 0·68 (0·34–1·38) | 0·069 | 71 (28%) | 1·17 (0·65–2·11) | 0·59 | 89 (29%) | 0·72 (0·36–1·43) | 0·35 | |
| ≥30 | 107 (15%) | 0·62 (0·37–1·04) | 0·284 | 35 (15%) | 0·71 (0·35–1·44) | 0·348 | 43 (14%) | 0·57 (0·24–1·35) | 0·198 | |
| Comorbidities | ||||||||||
| No hypertension | 623 (88%) | 1 (ref) | .. | 234 (86%) | 1 (ref) | .. | 282 (85%) | 1 (ref) | .. | |
| Hypertension | 75 (12%) | 1·56 (0·79–3·10) | 0·204 | 27 (14%) | 0·73 (0·36–1·47) | 0·379 | 42 (15%) | 1·02 (0·46–2·24) | 0·966 | |
| No autoimmune disease | 650 (93%) | 1 (ref) | .. | 226 (87%) | 1 (ref) | .. | 281 (87%) | 1 (ref) | .. | |
| Autoimmune disease | 48 (7%) | 0·63 (0·27–1·48) | 0·292 | 35 (13%) | 0·67 (0·32–1·38) | 0·278 | 43 (13%) | 0·89 (0·35–2·26) | 0·812 | |
| No diabetes | 663 (95%) | 1 (ref) | .. | 249 (93%) | 1 (ref) | .. | 308 (92%) | 1 (ref) | .. | |
| Diabetes | 35 (6%) | 0·92 (0·39–2·19) | 0·855 | 12 (7%) | 0·53 (0·21–1·30) | 0·166 | 16 (8%) | 0·30 (0·13–0·73) | 0·008 | |
| No lung disease | 672 (96%) | 1 (ref) | .. | 249 (95%) | 1 (ref) | .. | 310 (95%) | 1 (ref) | .. | |
| Lung disease | 26 (4%) | 0·88 (0·28–2·81) | 0·831 | 12 (5%) | 0·89 (0·31–2·60) | 0·838 | 14 (5%) | 0·61 (0·19–1·98) | 0·408 | |
| No heart disease | 680 (97%) | 1 (ref) | .. | 253 (96%) | 1 (ref) | .. | 313 (95%) | 1 (ref) | .. | |
| Heart disease | 18 (3%) | 0·81 (0·30–2·16) | 0·674 | 8 (4%) | 1·42 (0·45–4·49) | 0·553 | 11 (5%) | 0·63 (0·20–1·93) | 0·414 | |
| No immunosuppression | 688 (98%) | 1 (ref) | .. | .. | .. | .. | .. | .. | .. | |
| Immunosuppression¶ | 10 (2%) | 0·07 (0·02–0·24) | <0·0001 | .. | .. | .. | .. | .. | .. | |
Data are from the multivariate logistic regression analysis model. IgM antibodies were detected in very few individuals and for only a short time and are therefore not included in the table. ref=reference value. BMI=body-mass index. ..=data not available.
IgG >0·62, IgA >1·1, and neutralising antibodies >10 were considered positive.
Week 3 refers to the week that the second vaccination dose was administered. Week 4 refers to the week following the second vaccination dose.
IgA and neutralising antibodies were assessed in the enriched subgroup and not the full cohort.
Global p value.
Immunosuppression included organ transplantation; being on biologic therapy, chemotherapy, or steroids; and splenectomy.