Clinical characteristics of 909 cases infected by Omicron BF.7 variant in Hohhot of China: A retrospective study

A clinical survey on 909 patients with SARS-CoV-2 subvariant BF.7 infection was conducted in Hohhot First Hospital in Hohhot, China, from October 3 to October 22, 2022. Medical records of patients were reviewed by 2 physicians, respectively. The majority of cases (over 80%) showed mild symptoms, while 25% had a history of chronic medical illness or comorbidities, including cardiovascular and cerebrovascular diseases (14%), metabolic disease (7%), obesity (4%) and others. Common symptoms of BF.7 infection included cough (70%), sore throat (53%), expectoration (51%), and fever (41%). Around 75% of patients were discharged within 2 weeks of noninvasive mechanical ventilation and traditional Chinese medicine treatment. This study also resulted in that vaccination was ineffective against BF.7 virus infection, while elderly patients with incomplete COVID-19 vaccination and preexisting chronic diseases were at higher risk for moderate or severe BF.7 infection. In conclusion, this study analyzed clinical characteristics of patients infected by BF.7 virus, emphasizing the imperative to further explore effective vaccine and develop novel prevention and treatment strategies to cope with such a continuously mutating and evolving RNA virus infection and to minimize its threat and impact on human health, especially for vulnerable population.