Table 3.

IgG and neutralising antibody titres (ratio of means) following vaccination

	IgG, weeks 0–3*(n=793)	Neutralisation, weeks 0–3*(n=368)	IgG, weeks 3–5*(n=1395)	Neutralisation, weeks 3–4*(n=419)
Sex
Male (vs female)	0·77 (0·67–0·88)	0·7 (0·50–0·97)	1·09 (0·92–1·28)	0·77 (0·52–1·14)
Age (years)
46–65·99 (vs 18–45·99)	0·52 (0·46–0·58)	0·57 (0·43–0·75)	1·66 (1·43–1·93)	1·04 (0·74–1·46)
≥66 (vs 18–45·99)	0·25 (0·19–0·31)	0·28 (0·18–0·42)	2·66 (2·00–3·53)	0·93 (0·57–1·51)
BMI (kg/m2)
25–29·99 (vs <25)	0·92 (0·80–1·05)	0·99 (0·73–1·34)	1·14 (0·97–1·33)	0·80 (0·56–1·14)
≥30 (vs <25)	1·15 (0·97–1·37)	0·92 (0·62–1·35)	0·91 (0·74–1·12)	0·61 (0·39–0·96)
Comorbidities
Hypertension	0·99 (0·82–1·20)	0·89 (0·59–1·34)	0·89 (0·71–1·13)	1·72 (1·07–2·79)
Autoimmune disease	0·87 (0·70–1·09)	0·78 (0·53–1·13)	0·94 (0·70–1·26)	0·97 (0·61–1·55)
Diabetes	1·03 (0·80–1·32)	0·83 (0·50–1·38)	0·84 (0·62–1·14)	0·70 (0·38–1·28)
Lung disease	0·74 (0·55–0·99)	0·64 (0·36–1·14)	1·56 (1·06–2·29)	1·21 (0·61–2·40)
Heart disease	0·69 (0·49–0·96)	0·92 (0·47–1·80)	1·28 (0·86–1·93)	0·64 (0·29–1·41)
Immunosuppression†	0·21 (0·14–0·31)	..	2·45 (1·35–4·45)	..

Data are ratios of means (95% CI) from the linear mixed analysis model. BMI=body-mass index. ..=data not available.

^*The inductions in IgG and neutralising antibody titres were measured 3 weeks after the first vaccination dose (first-dose effects); and between 3 and 5 weeks for IgG, or between 3 and 4 weeks for neutralising antibodies for the second-dose effects (neutralising antibodies were not assessed at 5 weeks). Week 3 refers to the administration of the second vaccination dose, and weeks 4 and 5 are the first and second weeks following the second vaccination dose, respectively.

^†Immunosuppression included organ transplantation; being on biologic therapy, chemotherapy, or steroids; and splenectomy.