Table 1 Characteristics of the studies selected in the systematic review and meta-analysis
| Â | Authors | Date | Study Design | Vaccine | Viral variant | Study population | Patients (age) | Adverse events | Level of evidence: preventing MIS-C | Level of evidence: safety |
|---|---|---|---|---|---|---|---|---|---|---|
Studies focusing on effectiveness of COVID-19 vaccination against MIS-C. | Â | |||||||||
1 | Zambrano et al.(29) | 2022, January | Case-control study | BNT162b2 (Pfizer-BioNTech); 2 doses | Delta | 102 MIS-C cases, 5 fully vaccinated, 97 unvaccinated. United States. | 12–18 years | - | 2B | NA |
2 | Levy et al.(28) | 2021, December | Cohort study | BNT162b2 (Pfizer-BioNTech; > 95%), mRNA-1273 (Moderna; < 5%), and other COVID-19 vaccines (< 1%) | Delta | 33 MIS-C cases, none fully vaccinated, 7 partially vaccinated, 26 unvaccinated. France. | 12–18 years | - | 2B | NA |
3 | Nygaard et al.(30) | 2022, May | Cohort study | BNT162b2 (Pfizer-BioNTech) | Delta | 52 MIS-C cases, 1 fully vaccinated, 52 unvaccinated. Denmark. | Unvaccinated: < 18 years Vaccinated: 12–18 years | - | 2 C | NA |
4 | Miller et al.(32) | 2022, June | Case-control study | mRNA vaccine | Delta; Omicron | 763 MIS-C cases, 23 fully vaccinated, 40 partially vaccinated, 697 unvaccinated. United States. | 5–20 years | - | 2B | NA |
5 | Oliver et al. (39,48) | 2021, December | Risk-benefit analysis | BNT162b2 (Pfizer-BioNTech) | - | 130 MIS-C cases prevented. United States. | 5–11 years | - | 2 C | NA |
6 | Stein et al.(34) | 2022, January | Project report | BNT162b2 (Pfizer-BioNTech) | - | 220 MIS-C cases, 1 fully vaccinated. Israel. | Unvaccinated: < 18 years Vaccinated: 12–18 years | - | 2 C | NA |
Studies focusing on MIS-C as a possible side effect of COVID-19 vaccination. | Â | |||||||||
7 | Ouldali et al. (36) | 2022, April | Population-based surveillance | BNT162b2 (Pfizer-BioNTech); mRNA-1273 (Moderna) | - | 12 cases of hyperinflammation syndrome. | 12–17 years | - | 2 C | NA |
8 | Yousaf et al. (35) | 2022, February | Surveillance study | BNT162b2 (Pfizer-BioNTech); mRNA-1273, Ad26.COV2.S | Delta | 1 MIS-C case per million individuals receiving one or more doses. | 12–20 years | - | 2 C | NA |
9 | Hoste et al. (37) | 2022, May | Cross-sectional survey | mRNA vaccine | - | 273 patients with a MIS-C history, no relapse. | - | No relapses in individuals with history of MIS-C. | 2Â C | NA |
Studies about COVID-19 vaccine safety, immunogenicity and efficacy. | Â | |||||||||
10 | Creech et al.(3) | 2022, May | RCT | mRNA-1273 (Moderna) | Delta | - | 6–11 years | No cases of MIS-C were reported. | NA | 1B |
11 | Walter et al.(2) | 2022, April | RCT | BNT162b2 (Pfizer-BioNTech) | Delta | - | 5–11 years | No cases of MIS-C were reported. | NA | 1B |
Other. | ||||||||||
12 | Curatola et al. (45,49) | 2022, February | Brief report | - | Omicron | - | - | - | - | - |
13 | Mangat et al. (38) | 2022, March | Editorial letter | - | Omicron | - | - | - | - | - |