Linear regression models of variables affects the magnitude of the antibody response against the SARS-CoV-2 spike glycoprotein
| Variable | IgG ratio | IgA ratio | IgM ratio | ||||||
| OR (95% CI) | t | P value | OR (95% CI) | t | P value | OR (95% CI) | t | P value | |
| Age | 0.03 (0.01 to 0.05) | 2.89 | 0.0043 | 0.01 (−0.01 to 0.03) | 1.21 | 0.26 | 0.00 (−0.01 to 0.02) | 0.03 | 0.97 |
| Sex (female) | −0.02 (−0.51 to 0.48) | 0.07 | 0.95 | 0.17 (−0.27 to 0.60) | 0.78 | 0.45 | 0.14 (−0.19 to 0.48) | 0.84 | 0.4 |
| Ethnicity (BAME) | 0.98 (0.49 to 1.47) | 3.95 | 0.0001 | −0.05 (−0.46 to 0.35) | 0.25 | 0.8 | 0.42 (0.09 to 0.76) | 2.53 | 0.02 |
| BMI | 0.07 (0.03 to 0.11) | 3.62 | 0.0004 | −0.02 (−0.05 to 0.01) | 1.42 | 0.15 | 0.00 (−0.03 to 0.04) | 0.22 | 0.83 |
| Time from symptom onset | −0.01 (−0.03 to 0.01) | 1.27 | 0.22 | −0.02 (−0.04 to −0.01) | 2.76 | 0.007 | −0.01 (−0.02 to 0.01) | 1 | 0.32 |
| Index of multiple deprivation | 0.16 (−0.13 to 0.45) | 1.09 | 0.28 | −0.10 (−0.36 to 0.16) | 0.78 | 0.44 | −0.17 (−0.41 to 0.07) | 1.43 | 0.32 |
| Primary symptoms | 0.19 (−0.03 to 0.66) | 0.78 | 0.44 | 0.27 (−0.14 to 0.67) | 1.31 | 0.19 | 0.25 (−0.16 to 0.65) | 1.24 | 0.22 |
The IgG, IgA and IgM ratios were used as dependent variables and participants’ age, sex, ethnicity, body mass index, time from symptom onset, the index of multiple deprivation score, whether an individual isolated because they directly experienced symptoms or isolated because a family member experienced symptoms and public transport use in the 2 weeks prior to isolation were used as independent variables. ORs and 95% CIs are provided. For continuous variables, the OR represents the increase in immunoglobulin ratio associated with each unit increase in that variable. For categorical variables, the OR represents the increase in immunoglobulin ratio associated the variable in parenthesis.
BAME, black, Asian and minority ethnic; BMI, body mass index.