Study on specific antibodies in patients infected with SARS-CoV-2 and recipients of inactivated vaccine

Objective To detect the serum levels of SARS-CoV-2-specific IgM and IgG antibodies in patients infected with SARS-CoV-2 and recipients of inactivated vaccine in different periods for understanding their variation patterns in vivo. Methods Chemiluminescence immunoassay was used to detect the levels of SARS-CoV-2-specific IgM and IgG antibodies in 144 serum samples of 44 COVID-19 patients, 381 serum samples of 118 asymptomatic infected cases and 398 serum samples of 273 inactivated vaccine recipients collected at different periods. The results were statistically analyzed together with basic characteristics and vaccination status. Results The positive rates of IgM antibody in COVID-19 patients, asymptomatic infected cases and inactivated vaccine recipients were 52. 27% (23 / 44), 23. 73% (28 / 118) and 14. 29% (39 / 273). The positive rate of IgM antibody was higher in COVID-19 patients than in asymptomatic infected cases and vaccine recipients (χ2 = 12. 106, P = 0. 001;χ2 = 34. 755, P<0. 001). The positive rates of IgG antibody in the three populations were 100. 00% (44 / 44), 97. 46% (115 / 118) and 98. 81% (166 / 168), and the differences were not statistically significant (χ2 = 2. 944, P = 0. 229). In COVID-19 patients, the concentration of IgM antibody in <40 years old group was lower than that in ≥40 years old group (Waldχ2 = 6. 609, P = 0. 010), and the concentration of IgG antibody in patients with vaccination was higher than that in patients without vaccination (Waldχ2 = 12. 402,P<0. 001). In asymptomatic infected cases, the concentration of IgG antibody was higher in people with vaccination than in those without vaccination (Waldχ2 = 4. 530, P = 0. 033). In SARS-CoV-2 vaccine recipients, the concentration of IgG antibody in <40 years old group was higher than that in ≥40 years old group (Waldχ2 = 9. 565, P = 0. 002). Dynamic analysis of antibody levels showed that from week 1 to week 9, the concentrations of IgM and IgG antibodies in COVID-19 patients were higher than those in asymptomatic infected cases and vaccine recipients. Conclusions The concentrations of IgM and IgG antibodies in COVID-19 patients were higher than those in asymptomatic infected cases and inactivated vaccine recipients. COVID-19 patients aged ≥40 years had higher level of IgM antibody. COVID-19 patients and asymptomatic infected cases who had received vaccination had higher concentration of IgG antibody. Inactivated vaccine showed good immunogenicity after whole course of immunization, and the IgG antibody level in <40 years old group was higher.

Do energy policies bring about corporate overinvestment? Empirical evidence from Chinese listed companies

In an era of profound changes in the global economic and industrial landscape, the ability of renewable energy policies to create new growth drivers is critical to achieving China's economic recovery in the post-COVID-19 period. Consequently, this paper empirically examines whether renewable energy policies bring about corporate overinvestment. Using corporate investment data and hand-curated information on energy firms from Chinese listed companies from 2007 to 2018, the results show that implementing renewable energy policies causes firms to overinvest. Renewable energy investment is more of a government-led industrial policy, reflecting how local governments increase their degree of intervention in firm investment, leading to overinvestment and better short-term firm performance. However, in the long run, the overinvestment encouraged by renewable energy policies will more negatively impact the economic performance of state-owned enterprises (SOEs). Moreover, when economic policy uncertainty is high, renewable energy policies can lead to a more pronounced tendency for firms to overinvest. Despite this trend, renewable energy policies do not significantly increase the likelihood of overinvestment among firms with high state-owned or equity concentration but instead allow firm operators to make more rational investment decisions. Thus, the government should formulate policies to regulate the investment process of enterprises and avoid distorting their investment behavior when providing financial support and preferential policies. © 2021 Elsevier B.V.

Nursing management at a Chinese fever clinic during the COVID-19 pandemic.

BACKGROUND: The rampant spread of the novel coronavirus disease (COVID-19) has assumed pandemic proportions across the world. Attempts to contain its spread have entailed varying early screening and triage strategies implemented in different countries and regions. AIM: To share the experience of scientific and standardized management of fever clinics in China, which provide the first effective checkpoint for the prevention and control of COVID-19. INTRODUCTION: A fever clinic was established at our hospital in Tianjin, China, for initially identifying suspected cases of COVID-19 and controlling the spread of the disease. METHODS: The management system covered the following aspects: spatial layout; partitioning of functional zones; a work management system and associated processes; management of personnel, materials and equipment; and patient education. RESULTS: Within two months of introducing these measures, there was a comprehensive reduction in the number of new COVID-19 cases in Tianjin, and zero infections occurred among medical staff at the fever clinic. DISCUSSION: The fever clinic plays an important role in the early detection, isolation and referral of patients presenting with fevers of unknown origin. Broad screening criteria, an adequate warning mechanism, manpower reserves and staff training at the clinic are essential for the early management of epidemics. CONCLUSION: The spread of COVID-19 has been effectively curbed through the establishment of the fever clinic, which merits widespread promotion and application. IMPLICATIONS FOR NURSING AND HEALTH POLICIES: Health managers should be made aware of the important role of fever clinics in the early detection, isolation and referral of patients, and in the treatment of infectious diseases to prevent and control their spread. In the early stage of an epidemic, fever clinics should be established in key areas with concentrated clusters of cases. Simultaneously, the health and safety of health professionals require attention.

Risk of SARS-CoV-2 infection among contacts of individuals with COVID-19 in Hangzhou, China.

OBJECTIVES: This study determined the rate of secondary infection among contacts of individuals with confirmed coronavirus disease 2019 (COVID-19) in Hangzhou according to the type of contacts, the intensity of contacts, and their relationship with the index patient. STUDY DESIGN: This is a retrospective cohort study. METHODS: The analysis used the data of 2994 contacts of 144 individuals with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The contacts were categorized according to the information source, type of contact, location, intensity of contact, and relationship with the index patient. RESULTS: The incidence of infection differed significantly according to contact type. Of the contacts, 186 (6.2%) developed symptoms, and 71 (2.4%) had confirmed SARS-CoV-2 infection. The main symptoms were cough and fever. Compared with those who had brief contact with the index case, those who had dined with the index case had 2.6 times higher risk of acquiring infection; those who had shared transport with, had visited, or had contact with the index case in a medical institution had 3.6 times higher risk of acquiring infection; and household contacts had 41.7 times higher risk of acquiring infection. Family members had 31.6 times higher risk of acquiring infection than healthcare providers or other patients exposed to an index case. CONCLUSIONS: The form and frequency of contact are the main factors affecting the risk of infection among contacts of individuals with COVID-19. Centralized isolation and observation of close contacts of individuals with confirmed SARS-CoV-2 infection, in addition to population-based control measures, can reduce the risk of secondary infections and curb the spread of the infection.