| Study | Population | n | Anti-TNF type (n) | Duration anti-TNF | Methotzrexate(%) | Mean age(years) | GMTs* | Protection rates† | Author conclusions |
| Gelinck (present study) | Mixed | 64 | i/e/a (29/14/21) | 2y | 65 | 51 | −60/−35/−57 | −6/−5/−9 | “significant inhibition of GMTs by anti-TNF, without lowering protection rates” |
| 48 | – | – | 76 | 47 | Reference group | ||||
| HC | 18 | – | – | – | 47 | +25/+35/+14 | +11/+5/+1 | ||
| Kaine 20077 | RA | 99 | a | 1 week (40 mg) | 56 | 52 | −22/−14/−20 | −19‡ | “adalimumab does not diminish humoral response, the majority of patients are protected” |
| 109 | – | – | 54 | 51 | Reference group | ||||
| Kapetanovic 20068 | RA | 50 | i/e (37/13) | 0.7y | 100 | 53 | −42/−70/−49 | −26/−42/−12 | “immune response sufficiently large, regardless of treatment” |
| 62 | i/e (27/35) | 1.1y | 0 | 54 | +12/−60/−39 | −3/−35/−8 | |||
| 37 | – | – | 100 | 61 | Reference group | ||||
| HC | 18 | – | – | – | 30§ | −15/−31/−61 | −5/−12/−29 | ||
| Fomin 20069 | RA | 27 | i/e (22/5) | ⩾3mo | 68 | 59 | Not reported separately | +31/+27/+18¶ | “infliximab does not affect the humoral response” |
| 55 | – | – | reference group | ||||||
| HC | 30 | – | – | – | 53 | +9/+9/+15 | +2/+28/+30** | ||
The study outcomes are expressed as percentage higher (+) or lower (–) post-vaccination outcomes in the different study groups as compared with a reference patient group.
*Relative percentage higher or lower post-vaccination GMTs as compared with reference patient group (for, respectively, influenza A/H3N2, A/H1N1 and influenza B); “−70” indicates a post-vaccination titre 70% lower than the reference group.
†Relative percentage higher or lower protection rate as compared with reference patient group (for, respectively, influenza A/H3N2, A/H1N1 and influenza B), unless stated otherwise; “+10” indicates a (relative) 10% higher protection rate as compared with the reference group.
‡Pooled data of three antigens (protective antibodies against ⩾2 of 3 influenza antigens).
§Based on mean age of 47 healthy controls in pneumococcal vaccination study.
¶Difference (%) in percentage of responders (defined as either seroconversion or a fourfold titre increase in patients with a protective titre before vaccination) in patients treated with infliximab (n = 22) versus no infliximab (n = 60, including five patients with etanercept).
**Difference (%) in percentage of responders (defined as either seroconversion or a fourfold titre increase in patients with a protective titre before vaccination) in all patients (n = 82) versus healthy controls (n = 30)
anti-TNF, anti-tumour necrosis factor α therapy; GMT, geometric mean titre; RA, rheumatoid arthritis; HC, healthy control; i, infliximab; a, adalimumab; e, etanercept; y, years; mo, months.