Objectives Describe the outcomes of patients treated at the Myasthenia Centre at Oxford University Trust who developed COVID-19 during the first year of the pandemic.

Methods Retrospective audit of patients diagnosed with COVID-19 between 31^st January 2020 – 31^st January 2021. Outcomes of COVID-19 complications, including relapse of myasthenia gravis (MG), were analysed.

Results The Myasthenia Centre treated 487 patients, including 370 with acetylcholine receptor (AChR) MG, 74 sero-negative MG, 20 MuSK MG and 23 Lambert-Eaton Myasthenic Syndrome (LEMS). COVID-19 was diagnosed in a total of twelve patients (2.5%) including ten AChR, one MuSK and one LEMS patient, with a mean age of 63.8 years (range 20 – 92 years). Five patients were asymptomatic of MG prior to the diagnosis of COVID-19. Treatments prior to diagnosis included pyridostigmine (8/12), prednisolone (7/12), azathioprine (3/12), mycophenolate (1/12) and rituximab (1/12). The majority (8/12) had at least one other co-morbid risk factor for severe COVID-19.

COVID-19 resulted in hospital admission in six patients, with three requiring intensive care treatment. One patient with AChR MG (with NHL and NMO treated with rituximab) died from COVID-19 without MG relapse. Two elderly patients developed moderate COVID-19 after a single dose BioNTech vaccination without MG relapse.

MG relapse occurred in four patients post COVID-19, with two requiring inpatient management including IVIG.

Conclusion COVID-19 disease was associated with relapse of MG, with all patients in this group surviving. Further research is required to establish if COVID-19 precipitates MG relapse at a different rate compared to other infectious diseases.