Summary of findings for the main comparison. Live zoster vaccine versus placebo for preventing herpes zoster in older adults.
| Live zoster vaccine versus placebo for preventing herpes zoster in older adults | ||||||
| Patient or population: healthy older adults aged ≥ 60 years Settings: outpatients Intervention: live zoster vaccine versus placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No. of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Control | Live zoster vaccine versus placebo | |||||
| Incidence of herpes zoster, 3.1 years follow‐up Clinical or laboratory criteria Follow‐up: mean 3.1 years | 33 per 1000 | 16 per 1000 (14 to 19) | RR 0.49 (0.43 to 0.56) | 38,546 (1 study) | ⊕⊕⊕⊝ moderate1 | NNTB = 50 |
| Participants with adverse events Clinical or laboratory criteria Follow‐up: mean 3.1 years | 344 per 1000 | 584 per 1000 (553 to 615) | RR 1.71 (1.38 to 2.11) | 7119 (5 studies) | ⊕⊕⊕⊝ moderate1 | NNTH = 4.3 |
| Death Clinical criteria Follow‐up: mean 3.1 years | 32 per 1000 | 32 per 1000 (29 to 35) | RR 1.01 (0.92 to 1.11) | 50,820 (5 studies) | ⊕⊕⊕⊝ moderate1 | |
| Participants with adverse events: 1 or more serious adverse events regardless of type of storage of the vaccine Clinical or laboratory criteria Follow‐up: mean 3.1 years | 22 per 1000 | 23 per 1000 (21 to 26) | RR 1.08 (0.95 to 1.21) | 51,029 (6 studies) | ⊕⊕⊕⊝ moderate1 | |
| Participants with adverse events ‐ systemic adverse events Clinical or laboratory criteria Follow‐up: mean 42 days | 227 per 1000 | 241 per 1000 (222 to 263) | RR 1.24 (0.82 to 1.87) | 7119 (5 studies) | ⊕⊕⊕⊝ moderate1 | |
| Participants with adverse events ‐ injection site adverse events Clinical criteria Follow‐up: mean 7 days | 161 per 1000 | 480 per 1000 (441 to 522) | RR 3.73 (1.93 to 7.21) | 7040 (4 studies) | ⊕⊕⊕⊝ moderate1 | NNTH = 3.6 |
| Dropouts Clinical or laboratory criteria Follow‐up: mean 3.1 years | 48 per 1000 | 47 per 1000 (43 to 51) | RR 0.99 (0.90 to 1.08) | 38,916 (3 studies) | ⊕⊕⊕⊝ moderate1 | |
| *The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; NNTB: number needed to treat for an additional beneficial outcome; NNTH: number needed to treat for an additional harmful outcome; RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1Most data came from a large study, and the quality of the evidence was downgraded because the trial did not describe the method used for random sequence generation.