This round of Tianjin epidemic began on August 27, 2022. According to the report of Tianjin Epidemic Prevention and Control Center, the whole genome sequencing of August 27 epidemic virus shows that it is highly homologous to the recently uploaded strains abroad. The frozen products produced in China collected from the homes of early positive infected people were positive, and the whole gene sequencing of the virus was consistent, confirming that the epidemic came from abroad.