Characteristics of two cases of breakthrough SARS-CoV-2 infections 14+days after the third dose of mRNA vaccine
| Case 1 | Case 2 | |
| Type of SARS-CoV-2 vaccine | mRNA-1273 (Moderna) | BNT162b2 (Pfizer-BioNTech) |
| Date of mRNA vaccine #1 | 29 January 2021 | 21 January 2021 |
| Date of mRNA vaccine #2 | 26 February 2021 | 11 February 2021 |
| Date of mRNA vaccine #3 | 22 August 2021 (T) | 25 August 2021 (T) |
| Date of breakthrough testing and type | 23 September 2021 Antigen test (Lumiradx) | 10 September 2021 qRT-PCR |
| Time from third mRNA dose to SARS-CoV-2 positive test | T+32 days | T+16 days |
| Days from symptom onset to SARS-CoV-2 positive test | 1 day | 2 days |
| Age at breakthrough infection | 31 years | 51 years |
| Sex | Female | Male |
| Race/ethnicity | White | White |
| Type of SARD | Juvenile idiopathic arthritis/seronegative inflammatory arthritis | Seropositive rheumatoid arthritis |
| SARD duration | 23 years | 14 years |
| Immunosuppressive medications | Adalimumab 40 mg SC every other week | Certolizumab pegol 200 mg SC every other week |
| Smoking status | Never smoker | Never smoker |
| Comorbidities | None | Hypertension, hyperlipidaemia, obesity, obstructive sleep apnoea |
| Body mass index (kg/m2) | 24.1 | 35.6 |
| Symptoms of COVID-19 | Rhinorrhoea, sore throat, dry cough, fever, fatigue, headache, diarrhoea, dysgeusia, anosmia | Fever, sore throat, dry cough, chest pain |
| Treatment of COVID-19 | Monoclonal antibody (casirivimab/imdevimab) on T+34 days | Supportive care |
| COVID-19 severity and course | Not hospitalised/fully recovered | Not hospitalised/fully recovered |
mRNA, messenger ribonucleic acid; SARD, systemic autoimmune rheumatic disease; SC, subcutaneous.