Omicron BF.7 became the predominant SARS-CoV-2 variant in Beijing after the adjustment of COVID-19 response strategies in December 2022. The ability of antibodies elicited by BF.7 infection to cross-react with SARS-CoV-2-like viruses is unknown. This study aimed to investigate the cross-reactive neutralizing antibodies against SARS-CoV-2-related pangolin coronavirus GX_P2V in sera from vaccinated and/or SARS-CoV-2 infected individuals. All vaccinated individuals who recovered from Omicron BF.7 breakthrough infections exhibited substantially higher levels of neutralizing antibodies against GX_P2V among collected subject populations (geometric mean titer [GMT] = 362). Uninfected individuals who received four-mixed-dose vaccines also demonstrated higher levels of neutralizing antibodies (GMT = 44) against GX_P2V than those who received two- or three-dose vaccines and those who recovered from wild type SARS-CoV-2. This finding highlights the significance of prior and hybrid booster vaccinations with wild-type SARS-CoV-2 vaccines in generating potent cross-protective immunity against future spillovers of SARS-CoV-2-like viruses.

Background: November 2022, a large number of Omicron infections suddenly appeared in Beijing, but the epidemiological and clinical characteristics of the epidemic cases are unknown. Methods: We collected the data of COVID-19 cases in Fangcang hospital in Beijing from November 20, 2022 to December 8, 2022, and analyzed the epidemiological and clinical characteristics. We used descriptive statistical methods to explore the basic characteristics, used parametric distribution to calculate the time to events, and used ArcGIS to explore the distribution patterns of COVID-19 cases in different areas. Results: There were 1,307 COVID-19 cases in the Fangcang shelter hospital enrolled the study, among which 85.9% were asymptomatic and 14.1% were mild. Epidemiological data showed that the transmission speed Omicron variant is fast and the transmission range is wide, large-scale infections have occurred in both rural and urban areas, and all age groups are susceptible to Omicron variant. In addition, antipyretics and cough drugs were the two most commonly used drugs, because 51.3% and 22.7% patients had fever and cough, respectively, and 10.3% patients took hypnotics. Furthermore, the proportion of patients with chronic diseases was low (13.9%), while the vaccination rate (71.2%) was relatively high. Conclusion: Based on the results of Fangcang shelter hospitals, we found that most mild and asymptomatic cases did not need treatment, which indicates that home isolation is correct and feasible. However, the transmission speed Omicron variant is fast and the transmission range is wide, and all age groups are susceptible to Omicron variant; therefore, the awareness of prevention and control should not be relaxed.