Core Viewpoint - The study highlights the significant impact of respiratory viral infections, such as influenza and SARS-CoV-2, on the awakening and proliferation of dormant disseminated cancer cells (DCC) in the lungs, which may lead to increased cancer-related mortality and metastasis risk [3][14][15]. Group 1: Research Findings - Influenza and SARS-CoV-2 infections can cause dormant DCC in the lungs to awaken, leading to rapid proliferation and metastasis [3][4]. - The research indicates that the presence of interleukin-6 (IL-6) is crucial for the reactivation of DCC, as its levels increase following viral infection [9][12]. - CD4+ T cells play a necessary role in maintaining the awakened state of DCC, although they are not required to initiate this process [12][14]. Group 2: Clinical Implications - The study found that cancer patients infected with SARS-CoV-2 have a significantly higher risk of cancer-related death and lung metastasis compared to those who are not infected [14][15]. - The findings suggest a potential link between respiratory infections and the recurrence of metastatic cancer, emphasizing the need for further exploration in this area [4][15]. Group 3: Mechanisms of Action - The research demonstrated that CD4+ T cells limit the ability of CD8+ T cells to control DCC growth, indicating a complex interplay between different immune cell types in the context of viral infections and cancer [12][14]. - The study also explored the role of inflammation caused by respiratory infections in influencing dormant cancer cells, which had not been a primary focus in previous research [7][8].

Core Insights - The recent rise in COVID-19 cases has drawn public attention, particularly following the announcement of singer Eason Chan's infection, indicating a potential resurgence of the virus in the population [1][2]. Summary by Sections COVID-19 Case Trends - In March 2025, a total of 56,286 new confirmed COVID-19 cases were reported across 31 provinces, with 131 severe cases and 7 deaths attributed to underlying health conditions combined with COVID-19 [2]. - The positivity rate for COVID-19 among influenza-like illness cases increased from 3.5% in the 10th week of 2025 to 6.3% by the end of March [2]. Variants and Mutations - The dominant COVID-19 variants in China have undergone multiple changes over the past two and a half years, transitioning from BA.5.2 and BF.7 to XDV and its sub-variants [1][3]. - The emergence of new variants with immune evasion capabilities has contributed to the re-infection of individuals and the occurrence of new infection peaks [3][4]. Seasonal Patterns and Infection Dynamics - Unlike typical respiratory viruses that peak in winter and spring, COVID-19 has shown a tendency to have peaks in summer as well, suggesting that its spread is more influenced by variant mutations and population immunity rather than seasonal changes [4][5]. - The current dominant variant, XDV and its sub-variant NB.1.8.1, has shown significant transmission advantages, affecting not only mainland China but also regions like Hong Kong, Macau, Japan, and South Korea [6]. Symptoms and Severity - The currently circulating variants have not shown new symptoms; common symptoms remain fever, sore throat, cough, and muscle pain, with a low proportion of severe cases overall [5][6].