Summary of findings for the main comparison.
Available live attenuated VZV zoster vaccine versus placebo for preventing herpes zoster in older adults
| Available live attenuated VZV zoster vaccine versus placebo for preventing herpes zoster in older adults | ||||||
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Patient or population: healthy older adults Settings: outpatients Intervention: available live attenuated VZV zoster vaccine Comparison: 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 | |||||
| Placebo | Available live attenuated VZV zoster vaccine | |||||
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Incidence of herpes zoster Clinical and laboratory criteria Follow‐up: median 3.1 years |
Study population | RR 0.49 (0.43 to 0.56) | 38,546 (1 study) | ⊕⊕⊕⊝ moderate1 | Absolute risk for available live attenuated VZV zoster vaccine = 1.6% Absolute risk for placebo group = 3.3% |
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| 33 per 1000 | 16 per 1000 (14 to 19) | |||||
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Participants with AEs: ≥ 1 serious AE regardless of type of storage of the vaccine Clinical and laboratory criteria Follow‐up: median 3.1 years |
Study population | RR 1.08 (0.96 to 1.2) | 50,896 (4 studies) | ⊕⊕⊕⊝ moderate1 | Absolute risk for available live attenuated VZV zoster vaccine = 2.3% Absolute risk for placebo group = 2.2% |
|
| 22 per 1000 | 23 per 1000 (21 to 26) | |||||
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Participants with AEs: hospitalised Number of participants hospitalised Follow‐up: median 3.1 years |
Study population | RR 1.00 (0.93 to 1.07) | 6616 (1 study) | ⊕⊕⊕⊝ moderate1 | Absolute risk for available live attenuated VZV zoster vaccine = 34.1% Absolute risk for placebo group = 34.1% |
|
| 341 per 1000 | 341 per 1000 (317 to 365) | |||||
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Participants with AEs: injection site AEs Clinical and laboratory criteria Follow‐up: median 3.1 years |
Study population | RR 2.99 (2.75 to 3.26) | 6986 (3 studies) | ⊕⊕⊕⊝ moderate1 | Absolute risk for available live attenuated VZV zoster vaccine = 47.9% Absolute risk for placebo group = 16.0% |
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| 160 per 1000 | 479 per 1000 (440 to 521) | |||||
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Drop‐outs: death Number of deaths Follow‐up: median 3.1 years |
Study population | RR 1.01 (0.92 to 1.11) | 50,687 (3 studies) | ⊕⊕⊕⊝ moderate1 | Absolute risk for available live attenuated VZV zoster vaccine = 3.3% Absolute risk for placebo group = 3.2% |
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| 32 per 1000 | 33 per 1000 (30 to 36) | |||||
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. 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). AE: adverse event; CI: confidence interval; 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. | ||||||
1Did not describe random sequence generation.