Coronaviruses are a large group of viruses known to cause disease in patients with different clinical symptoms ranging from the common cold to severe lung infections, such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) and the new coronavirus found in Wuhan this time. Therefore, its recurrence needs to be judged on a case-by-case basis. For Middle East Respiratory Syndrome (MERS), patients often present with symptoms such as fever, cough and shortness of breath, and pneumonia is often found on examination. Severe cases can lead to respiratory failure. There is no available vaccine or specific treatment for this disease, and supportive treatment is often used based on the patient’s clinical status. In patients who recover from Middle East respiratory syndrome, the disease can also recur once there is residual Middle East respiratory syndrome virus. In the case of severe acute respiratory syndrome (SARS), the disease first emerged in the winter of 2003. Patients often present with high fever, chills, headache, cough, and in severe cases, acute respiratory distress syndrome and organ failure. Whether there is seasonality in the disease and whether it recurs is uncertain, so more work in scientific research is needed. Similar to severe acute respiratory syndrome (SARS), the pathogen causing the novel coronavirus pneumonia this time is a new species of coronavirus that has not yet been identified in humans – the novel coronavirus. Regarding the recurrence of this virus, Liang Zong’an, director of the Department of Respiratory and Critical Care Medicine at West China Hospital of Sichuan University, said that patients will produce protective antibodies after infection and will be relatively safe for a period of time (usually several months). However, patients may still be re-infected in the following two situations: 1. The patient’s general health is poor and the concentration of antibodies produced in the body is low, which may lead to re-infection onset; 2. The virus has mutated and the antibodies are unable to recognize it, resulting in the previously produced antibodies being ineffective against the mutated virus, which leads to re-infection. Content source: Dr. You Lai Reference: National Health and Wellness Commission “Middle East Respiratory Syndrome Related Knowledge Q&A” National Health and Wellness Commission “Public Protection Guidelines for Pneumonia with Novel Coronavirus Infection” Chinese Center for Disease Control and Prevention “Coronavirus