Summary of findings 12. NVX‐CoV2373 – Novavax compared to placebo for vaccination against COVID‐19a.
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with NVX‐CoV2373 | |||||
| Confirmed SARS‐CoV‐2 infection | Outcome not yet measured or reported | |||||
| Confirmed symptomatic COVID‐19b | 1140 per 100,000 | 195 per 100,000 (67 to 564) |
VE 82.91 (50.49 to 94.10) |
42,175 (3 RCTs)c | ⊕⊕⊕⊖ Moderated,e | Substantial heterogeneity (I² = 65%) between included studies: Dunkle 2021 (VE 90.40%, 95% CI 82.88 to 94.62%; n = 25,452); Heath 2021 (VE 89.70%, 95% CI 80.20% to 94.60%; n = 14,039); Shinde 2021 (VE 49.40%, 95% CI 6.10% to 72.80%; n = 2684) |
| Severe or critical COVID‐19 | 172 per 100,000 | 0 per 100,000 (0 to 22) | VE 100.00 (86.99 to 100.00) | 25,452 (1 RCT)f | ⊕⊕⊕⊖ Moderated,g | — |
| All‐cause mortalityh | 51 per 100,000 | 46 per 100,000 (15 to 136) | RR 0.90 (0.30 to 2.68) | 29,582 (1 RCT)f | ⊕⊕⊖⊖ Lowd,i | 1 additional study reported on this outcome in 14,039 participants (7020 NVX‐CoV2373 versus 7019 placebo) (Heath 2021). There were no events in either group and the trial did not contribute to the pooled effect estimate. |
| Systemic reactogenicity eventsj | 363 per 1000 | 439 per 1000 (425 to 454) | RR 1.21 (1.17 to 1.25) | 31,063 (3 RCTs)k | ⊕⊕⊕⊕ Highl | — |
| Any adverse eventm | 173 per 1000 | 199 per 1000 (182 to 218) | RR 1.15 (1.05 to 1.26) | 46,231 (5 RCTs)n | ⊕⊕⊕⊖ Moderatel,o | Substantial heterogeneity (I² = 57%) between the 5 included studies. |
| Serious adverse eventsm | 777 per 100,000 | 715 per 100,000 (575 to 886) | RR 0.92 (0.74 to 1.14) | 38,802 (4 RCTs)p | ⊕⊕⊖⊖ Lowi,q | 1 additional trial reported on this outcome in 52 participants (29 NVX‐CoV2373 versus 23 placebo) (Keech 2020). There were no events in either group and the trial did not contribute to the pooled effect estimate. |
| Local reactogenicity eventsj | 191 per 1000 | 532 per 1000 (381 to 742) | RR 2.78 (1.99 to 3.88) | 31,063 (3 RCTs)k | ⊕⊕⊕⊕ Highl,r | — |
| *The risk in the intervention group (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). COVID‐19: coronavirus disease 2019 CI: confidence interval; RCT: randomized controlled trial; RR: risk ratio; SARS‐CoV‐2: severe acute respiratory syndrome coronavirus 2; VE: vaccine efficacy. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
aLast updated: 2 June 2022 bFollow‐up: from seven days after second dose up to three months (median) cDunkle 2021; Heath 2021; Shinde 2021 dDespite some concerns with deviations from intervention, not downgraded for risk of bias. eInconsistency: downgraded one level (I² = 65%). fDunkle 2021 gIndirectness: downgraded one level as outcome in this trial included participants with moderate severity. hFollow‐up: two months (median) iImprecision: downgraded two levels due to wide CIs consistent with the possibility of benefit and the possibility of harm and few events. jFollow‐up: seven days kDunkle 2021; Frenck 2021; Shinde 2021 lDespite some concerns with adequate randomisation and missing data, not downgraded for risk of bias. mUnsolicited adverse events, follow‐up to three months (median) nDunkle 2021; Formica 2021; Heath 2021; Keech 2020; Shinde 2021 oInconsistency: downgraded one level (I² = 57%). pDunkle 2021; Formica 2021; Heath 2021; Shinde 2021 qDespite some concerns with adequate randomisation, deviation from intended intervention and missing data, not downgraded for risk of bias. rDespite I² = 86%, not downgraded for inconsistency, as the same direction of effect in both effect estimates.