In December 2019, the COVID-19 pandemic quickly spread throughout China and beyond, posing enormous global challenges. With prompt, vigorous, and coordinated control measures, mainland China contained the spread of the epidemic within two months and halted the epidemic in three months. Aggressive containment strategy, hierarchical management, rational reallocation of resources, efficient contact tracing, and voluntary cooperation of Chinese citizens contributed to the rapid and efficient control of the epidemic, thus promoting the rapid recovery of the Chinese economy. This review summarizes China’s prevention and control strategies and other public health measures, which may provide a reference for the epidemic control in other countries.

Background The inactivated Sinopharm/BBIBP COVID‐19 vaccine has been widely used in the world and has joined the COVAX vaccine supply program for developing countries. It is also well adapted for usage in low‐ and middle‐income nations due to their low storage requirements. Objective This study aims to report on the kinetics, durability, and neutralizing ability of the induced immunity of the BBIBP vaccine, and the intensified antibody response elicited by the booster. Methods A total of 353 healthy adult participants, aged 20–74 years, were recruited in this multicenter study. A standard dose of the BBIBP vaccine was administered (Month 0), followed by a second standard dose (Month 1), and a booster dose (after Month 7). Vaccine‐induced virus‐specific antibody levels (SARS‐CoV‐2‐IgA/IgM/IgG), conventional virus neutralization test (cVNT), pseudovirus neutralization test (pVNT), and surrogate virus neutralization test (sVNT) were monitored over multiple time points. Results Neutralizing titers induced by the two doses of inactivated vaccine for COVID‐19 peaked at Month 2 and declined to 33.89% at Month 6. Following the booster dose, elevated levels of antibodies were induced for IgA, IgG, and neutralizing antibodies, with neutralizing titer reaching 13.2 times that of before the booster. Conclusion By monitoring the antibody titer levels postvaccination, this study has shown that serum antibody levels will decrease over time, but a notable spike in antibody levels postbooster highlights the anamnestic immune response. This signifies that the protection capability has increased following the injection of booster immunization.

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<b><i>Background:</i></b> The objective of this study was to evaluate the diagnostic value of serological markers Krebs von den Lungen-6 (KL-6), surfactant protein-A (SP-A), SP-D, chemokine ligand 2 (CCL2), and chemokine 13 (CXCL13) in idiopathic interstitial pneumonia (IIP). <b><i>Methods:</i></b> Patients with IIP aged 18–80 years from the First Affiliated Hospital of Guangzhou Medical University were enrolled in this retrospective case-control study. Data on the general patient characteristics, laboratory test results, chest high-resolution CT, and pulmonary function test results were collected. The diagnosis of idiopathic pulmonary fibrosis (IPF) was based on the international practice guidelines for the diagnosis and treatment of IPF, a collaborative effort published by the American Thoracic Society (ATS)/European Respiratory Association (ERS), Japanese Respiratory Society, and Latin American Thoracic Society. The diagnostic criteria of non-IPF (N-IPF) followed the consensus classification of the IIPs, which was jointly issued by the ATS and ERS in 2002. The diagnosis of interstitial pneumonia with autoimmune features (IPAF) was based on the official research statement on IPAF, which was jointly issued by the ATS and ERS in 2015. Serum levels of KL-6, SP-A, SP-D, CCL2, and CXCL13 were measured. The differences in the expression of these biomarkers and their correlation with the severity of the disease were analyzed. The sensitivity, specificity, cutoff value, and area under the curve (AUC) value for each of the indices were determined using the receiver operating characteristic (ROC) curve analysis. <b><i>Findings:</i></b> Between September 2015 and October 2017, 69 patients with IIP. Of these patients, 19 had IPF, 23 had N-IPF, and 27 had IPAF. We also enrolled 20 age- and gender-matched patients with pneumonia and 15 uninfected individuals as normal control. The serum levels of KL-6, SP-A, ­SP-D, CCL2, and CXCL13 were significantly higher in patients with IIP than in patients with pneumonia and the normal controls. The detection of these markers was found to have better diagnostic efficacy in patients with IIP than in those with pneumonia. Of these markers above, KL-6 had the highest diagnostic value (AUC 0.96, 95% CI 0.93–0.99). Based on a logistics regression analysis, the combination of KL-6, CCL2, and CXCL13 had an improved diagnostic efficacy for IIP. In patients with IIP, the serum levels of KL-6, SP-A, CCL2, and CXCL13 all showed a significant negative correlation with the diffusing capacity of the lungs for carbon monoxide (DLCO; <i>r</i> = –0.36, –0.37, –0.36, –0.30, respectively; all <i>p</i> &#x3c; 0.05). Although their expression levels along with that of SP-D were elevated in patients with IPF, N-IPF, and IPAF, it was difficult to distinguish between these 3 conditions by detecting the 5 serum biomarkers together. Our findings indicate that the serum levels of KL-6, SP-A, SP-D, CCL2, and CXCL13 are notably elevated in patients with IIP and show significant correlation with the severity of interstitial lung lesions. Additionally, we further explore the diagnostic efficacy of 5 biomarkers in different types of IIP. It is the first time that the level of serum marker CXCL13 of N-IPF and IPAF patients was higher than IPF patients, which further enriched the study on serum markers for IIPs. Between September 2015 and October 2017, 69 patients with IIP. Of these patients, 19 had IPF, 23 had N-IPF, and 27 had IPAF. We also enrolled 20 age- and gender-matched patients with pneumonia and 15 uninfected individuals as normal control. The serum levels of KL-6, SP-A, SP-D, CCL2, and CXCL13 were significantly higher in patients with IIP than in patients with pneumonia and the normal controls. Of these markers above, KL-6 had the highest diagnostic value (AUC 0.96, 95% CI 0.93–0.99). Based on a logistics regression analysis, the combination of KL-6, CCL2, and CXCL13 had an improved diagnostic efficacy for IIP. In patients with IIP, the serum levels of KL-6, SP-A, CCL2, and CXCL13 all showed a significant negative correlation with the DLCO (<i>r</i> = –0.36, –0.37, –0.36, –0.30, respectively; all <i>p</i> &#x3c; 0.05). Our findings indicate that the serum levels of KL-6, ­SP-A, SP-D, CCL2, and CXCL13 are notably elevated in patients with IIP and show significant correlation with the severity of interstitial lung lesions. Additionally, we further explore the diagnostic efficacy of 5 biomarkers in different types of IIP. It is the first time that the level of serum marker CXCL13 of N-IPF and IPAF patients was higher than IPF patients, which further enrich the study on serum markers in IIPs. <b><i>Interpretation:</i></b> Although the combined detection of KL-6, CCL3, and CXCL13 significantly improves the diagnosis of IIP, detection of all the 5 markers together is unable to distinguish between IPF, N-IPF, and IPAF.