Authors | Study design | Study participants | Sample size | Time from vaccination to onset of symptoms (Days) | Findings | Limitations |
---|---|---|---|---|---|---|
Parry et al. 2021 [8] | Observational | Older adults (80–99-years-old) | 165 | - | Antibody response in a large majority Enhanced T-cells response in ChAdOx1 than in BNT162b2 mRNA recipients | Small sample size Not peer-reviewed (as at the time of this review) |
Muller et al. 2021 [9] | Observational | Older persons (≥ 60-years-old) | 176 | - | After 2 doses of BTN162b2 mRNA vaccine, SARS-CoV-2 spike protein specific IgG antibody was lower in older persons (> 80-years-old) Detectable neutralising antibody titre was absent in many older persons, compared to younger persons | Small sample size |
Scully et al. 2021 [15] | Observational | 23 | 6 – 24 days after vaccination with ChAdOx1 | Vaccine-induced immune thrombotic thrombocytopeania (VITT) after ChAdOx1 vaccine Presence of Platelet Factor 4 (PF4) | Potential risk of ascertainment bias in associating adverse events with vaccination | |
Shultz et al. 2021 [17] | Observational | Persons of 32–52-years-old | 5 | 7 – 10 days after vaccination with ChAdOx1 | Suggests a possible development of vaccine-induced immune thrombotic thrombocytopenia after ChAdOx1 vaccine Presence of Platelet Factor 4 (PF4) | Potential risk of ascertainment bias |
Greinacher et al. 2021 [18] | Observational | Persons from Austria and Germany | 11 | 5 -16 days of vaccination ChAdOx1 | Development of immune thrombotic thrombocytopenia (ITT) after vaccination with ChAdOx1 nCov-19 Seen mostly in females Highly elevated D-dimer levels and low fibrinogen | Potential risk of ascertainment bias. Potential under-reporting of cases following passive surveillance |
Yocum et al. 2021 [19] | Case report | A 62-year-old female | 1 | 37 days of vaccination with Ad26.COV2-S | Low fibrinogen, low platelets and negative tests for PF4 (37 days after Ad26.COV2-S vaccine administration) Suspected vaccine-induced thrombotic thrombocytopenia | Potential risk of ascertainment bias |
Blauenfeldt et al. 2021 [21] | Case report | A 60-year-old woman | 1 | 7 days of vaccination with ChAdOx1 | Presence of IgG platelet factor 4. increase in D-dimer, thrombocytopenia and haemorrhage | Potential risk of ascertainment bias |
Wolf et al. 2021 [22] | Case series | Women between 22 and 46-years-old | 3 | 4 – 17 days after vaccination with ChAdOx1 | Elevated D-dimer, Presence of IgG platelet factor 4, presence of SARS-CoV-2 spike IgG | Potential risk of ascertainment bias |
See et al. 2021 [23] | Case series | Women of 18–< 60-years-old | 12 | 6 – 15 days after vaccination with Ad26.COV2.S | Positive results for Heparin–platelet factor 4 antibody, abnormal levels of D-dimer and fibrinogen, thrombocytopenia and haemorrhage | Potential risk of incomplete data from retrospective data collection |