4. Results of all the safety outcomes (adverse events, pregnancy outcomes).
| Outcomes | Absolute risk/ per 10,000 | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | |
| placebo | vaccinated | ||||
| Analysis 7.1Overall local/injection site adverse events | 6847 | 8080 |
1.18 (1.16 to 1.20) |
18,113 (8 studies) | ⊕⊕⊕⊝ moderate2 |
| Analysis 7.2Pain at injection site | 6505 | 8782 |
1.35 (1.23 to 1.49) |
25,691 (13 studies) | ⊕⊕⊕⊝ moderate2 |
| Analysis 7.3Swelling at injection site | 1582 | 2737 |
1.73 (1.32 to 2.27) |
22,106 (9 studies) | ⊕⊕⊕⊝ moderate2 |
| Analysis 7.4Redness at injection site | 1938 | 3333 |
1.72 (1.50 to 1.97) |
19,996 (6 studies) | ⊕⊕⊕⊝ moderate2 |
| Analysis 7.5Overall systematic event and general symptoms | 6102 | 6224 |
1.02 (0.98 to 1.07) |
18,191 (8 studies) | ⊕⊕⊕⊝ moderate2 |
| Analysis 7.6Serious adverse events | 605 | 611 |
1.01 (0.95 to 1.07) |
6978 (21studies) | ⊕⊕⊕⊕ high |
| Analysis 7.7Deaths | 11 | 13 |
1.25 (0.81 to 1.93) |
71,452 (23 studies) |
⊕⊕⊝⊝ low2,4,† |
| Analysis 8.1Normal infant | 7171 | 7171 |
1.00 (0.97 to 1.02) |
8782 (8 studies) | ⊕⊕⊕⊕ high |
| Analysis 8.2Spontaneous abortion/miscarriage | 1618 | 1424 |
0.88 (0.68 to 1.14) |
8618 (9 studies) | ⊕⊕⊕⊕ high |
| Analysis 8.3Elective termination/induced abortion | 931 | 838 |
0.90 (0.80 to 1.02) |
10.909 (9 studies) | ⊕⊕⊕⊕ high |
| Analysis 8.4Stillbirth | 70 | 78 |
1.12 (0.68 to 1.83) |
8754 (6 studies) | ⊕⊕⊕⊝4 moderate |
| Analysis 8.5Abnormal infant | 205 | 250 |
1.22 (0.88 to 1.69) |
9252 (5 studies) | ⊕⊕⊕⊝4 moderate |
| 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. *The attribution of "high quality" depends on the following conditions: well‐conducted randomized trials, with consistent findings, direct outcome, precise estimates (narrow confidence intervals), absence of reporting bias (Guyatt 2008). 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. | |||||
1In case of study flaws as assessed by Cochrane's tool for assessing risk of bias in randomised trials (Higgins 2011b), not observed but calculated outcome
2 Substantial heterogeneity defined as I2 > 30%, when multiple studies were available for the considered outcome
3When only one study was retrieved for the outcome
4Imprecision, when the width of the 95% confidence interval around RR > 0.60
† inter‐age group heterogeneity, absence of pattern in causes of deaths