You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

AIM OF THE STUDY: Coronavirus disease 2019 (COVID-19) incidence, mortality, recovery and hospitalisation rates vary in different countries. This study aimed to present the clinical characteristics of a sample of unvaccinated Polish myasthenia gravis (MG) patients during the first year of the COVID-19 pandemic, taking into account the number of MG exacerbations, a detailed description of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection course, and the need to modify immunosuppressive therapies. Clinical rationale for the study: To assess the impact of the first COVID-19 pandemic year on MG course in a sample of unvaccinated patients. MATERIALS AND METHODS: A retrospective observational study involving 30 unvaccinated Polish MG patients consulted in a neurological outpatient clinic on 11-31 March, 2020 (baseline) and 11-31 March, 2021 (endpoint). RESULTS: During the period of evaluation, exacerbation of MG requiring hospitalisation was reported in 11 patients. Among them, four were treated with intravenous immunoglobulin and another six required plasma exchange. In the study group, COVID-19 was identified in 10 patients. Of them, seven experienced a mild course of SARSCoV-2 infection with spontaneous recovery. In the remaining three patients, both MG exacerbation and SARS-CoV-2 infection were reported. These patients experienced MG exacerbation in the preceding month or concurrently with COVID-19 and were aged over 50 years. Due to the SARS-CoV-2 infection, they required antibiotic and oxygen therapy, and hospitalisation was necessary in the case of two obese patients. None of the patients died due to COVID-19, and nor did any require discontinuation of immunosuppressive therapies during the study period. In total, 12 patients in the study group experienced neither MG exacerbation nor SARS-CoV-2 infection. CONCLUSIONS: In the presented sample of Polish MG patients, favourable outcomes of COVID-19 were observed. Further studies are needed to evaluate the reliable course of COVID-19 taking into account international differences, the types of treatment applied, and the ratio of vaccinated to unvaccinated MG patients.
["Treatment", "Diagnosis"]