The original strain of New Coronary Pneumonia appeared early as a virus containing a mutation in the stinger protein, which continued to mutate after the epidemic, and the mutation gave rise to mutant strains such as Delta, Ramada, Alpha, Beta, etc. The clinical symptoms of mutant strains are generally not specific, and the early symptoms are mostly atypical. The mutated strains that have appeared in China are Delta and Ramada, and the early symptoms of infection with these two mutated viruses are more clearly understood, while other mutated strains are still under study: 1. Delta: Generally, the early symptoms of patients infected with Delta virus are not typical, and many patients only show weakness, smell impairment, mild muscle aches, etc. A few patients will have nasal congestion, sore throat, conjunctivitis, diarrhea, etc. A few patients may develop nasal congestion, sore throat, conjunctivitis and diarrhea. The symptoms are more insidious than those of the primary strain, so when the above symptoms appear, it is necessary to consult a doctor in time to determine whether there is an infection with the Delta mutant strain; 2. Ramada: The Ramada mutant strain is exported from outside China and introduced into China. The Ramada mutant strain is more similar to the Delta virus, and the infected person will have symptoms such as cough, fever, taste and smell impairment, as well as body pain and shortness of breath. Although the Ramada strain is not endemic in China, it is important to take protective measures to prevent the virus from invading.