Aged ; Humans ; COVID-19 Vaccines ; COVID-19/prevention & control* ; Vaccination

Coronavirus disease 2019 (COVID-19) has become a global pandemic disease. SARS-CoV-2 variants have aroused great concern and are expected to continue spreading. Although many countries have promoted roll-out vaccination, the immune barrier has not yet been fully established, indicating that populations remain susceptible to infection. In this review, we summarize the literature on variants of concern and focus on the changes in their transmissibility, pathogenicity, and resistance to the immunity constructed by current vaccines. Furthermore, we analyzed relationships between variants and breakthrough infections, as well as the paradigm of new variants in countries with high vaccination rates. Terminating transmission, continuing to strengthen variant surveillance, and combining nonpharmaceutical intervention measures and vaccines are necessary to control these variants.
COVID-19/prevention & control* ; COVID-19 Vaccines ; Humans ; Pandemics/prevention & control* ; SARS-CoV-2

The COVID-19 outbreak at the end of 2019 has accelerated the development and research for COVID-19 vaccines worldwide. Among the COVID-19 vaccines in clinical trials developed via different platforms, recombinant virus vector-based vaccines have shown excellent immunogenicity and efficacy. However, at the same time, there are serious issues such as vaccine safety and pre-existing antibodies against vectors. This article summarizes the design concept and development history of recombinant virus vector-based vaccines, and focuses on the progress in the clinical studies of vector-based COVID-19 vaccines as well as the challenges, in order to provide reference for the research of recombinant vector-based vaccines.
COVID-19/prevention & control* ; COVID-19 Vaccines ; Genetic Vectors ; Humans ; Vaccines, Synthetic ; Viral Vaccines

To analyze the usage and loss of the COVID-19 vaccine in ten districts of Suzhou city from December 18, 2020 to April 30, 2021.The results showed the loss rate was 0.222‰ in Suzhou city. The loss rate of pre-filled packaging COVID-19 vaccine was higher than that of vial packaging. The loss rate of 40 packaging was the lowest in vial packaging. The loss rate of all kinds of COVID-19 vaccine in stable inoculation unit was the lowest. It is recommended to distribute 40 vial packaging COVID-19 vaccine for centralized vaccination to reduce the loss of COVID-19 vaccine.
Humans ; COVID-19 Vaccines ; COVID-19/prevention & control* ; Vaccination ; Cities ; Drug Packaging

Objective: To evaluate the methodology of the published systematic reviews and Meta-analyses (SR/MA) on efficacy and safety of coronavirus disease 2019 (COVID-19) vaccines. Methods: We conducted a retrieval for literatures published as of December 10, 2021 in English databases (Medline, Embase, Cochrane Library, Web of science) and Chinese databases (CNKI, Wanfang data, VIP, Sinomed). Two reviewers independently screened literatures and extracted data. The methodology of included SR/MA papers was assessed by A MeaSurement Tool to Assess systematic Review-2 (AMSTAR-2) tool in 16 items. Results: A total 22 SR/MA papers were included, in which 3 (13.6%) had low quality and 19 (86.4%) had very low quality. The main problems of these SR/MA included having no definite PICO (Participants, intervention, control and outcome), providing no preliminary research protocol, no list of excluded studies and justify the exclusions, making no evaluation and explanation or discussion of the risk of bias of original studies, no adequate evaluation of publication bias and discuss its likely impact on the results, etc. Conclusion: SR/MA for the efficacy and safety of COVID-19 vaccines had varied methodological deficiencies, further improvements are needed.
COVID-19/prevention & control* ; COVID-19 Vaccines/adverse effects* ; Humans ; Meta-Analysis as Topic ; Systematic Reviews as Topic

As of December 31, 2021, Singapore reported that 4 758 601 had completed at least one dose of COVID-19 vaccination, 4 714 655 had completed two doses of COVID-19 vaccination, and 2 207 341 had received one booster shot of COVID-19 vaccine. This article analyses the current performance of COVID-19 vaccination in Singapore, interprets the content of Singapore's National Vaccination Programme, and systematically introduces specific measures of COVID-19 vaccination in Singapore, such as door-to-door vaccination, vaccination differentiated management, and self-payment of medical expenses for those who refuse to be vaccinated, to provide reference for the COVID-19 vaccination in China.
COVID-19/prevention & control* ; COVID-19 Vaccines ; Humans ; Immunization Programs ; Singapore ; Vaccination

Objective: To understand the research progresses of economic evaluation of COVID-19 vaccination strategies both at home and abroad, and provide reference for the economic evaluation of COVID-19 vaccination strategies using real word data in China. Methods: Literature retrieval was conducted for related papers published from January, 2020 to December, 2021 in Chinese and English databases, including the economic evaluation of COVID-19 vaccination, and the results of the related literatures were narratively integrated. Results: A total of 16 English literatures (including 3 reviews) were included, and it was found that the COVID-19 vaccination was cost-effective or cost-saving regardless of the vaccine types, while the cost-effectiveness in different population and under different vaccination dose strategies varied due to vaccine efficacy, vaccine price, duration of natural immunity, duration of vaccination campaign, vaccine supply, and vaccination pace. Conclusions: China lacks suitable evidences of economic evaluation of COVID-19 vaccination strategies based on real-world data in the context of long-term epidemic. Therefore, further researches of suitable strategies of booster COVID-19 vaccination are needed.
COVID-19/prevention & control* ; COVID-19 Vaccines ; China/epidemiology* ; Cost-Benefit Analysis ; Humans ; Vaccination

The pandemic of COVID-19 threatens the health and safety of the people all over the world. COVID-19 vaccine is the key public product to establish population immune barrier and achieve the global contain of the pandemic. The World Health Organization, the Global Alliance for Vaccines and Immunization and the Coalition for Epidemic Preparedness Innovations established COVID-19 Vaccines Global Access Facility (COVAX) in 2020, aiming to enable the fair access to COVID-19 vaccine by all countries in the world, especially the low- and middle-income countries. Although COVAX has facilitated the production and research of COVID-19 vaccine by coordinating the global supply chain, the implementation of COVAX is still facing many difficulties in financing, implementation and the awareness of public, revealing the problems of global health governance. Taking COVAX as an example, this paper analyzes the difficulties faced by global health governance and explore the underlying causes, so as to suggest feasible short and long-term paths for China's participation in global governance.
COVID-19/prevention & control* ; COVID-19 Vaccines ; Global Health ; Humans ; SARS-CoV-2 ; Vaccines

COVID-19/prevention & control* ; COVID-19 Vaccines ; Health Personnel ; Humans ; Singapore ; Vaccination

OBJECTIVES: To study the clinical features of children with coronavirus disease 2019 (COVID-19) Delta variant infection vaccinated or not vaccinated with inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. METHODS: A total of 11 children with COVID-19 Delta variant infection who were vaccinated with inactivated SARS-CoV-2 vaccine and were hospitalized in the designated hospital in Henan Province, China, from November 3 to December 17, 2021 were enrolled as the vaccinated group. Thirty-one children with COVID-19 Delta variant infection who were not vaccinated and were hospitalized during the same period were enrolled as the unvaccinated group. A retrospective analysis was performed on their epidemiological data, clinical features, and laboratory examination results. RESULTS: There was no significant difference in gender composition and disease classification between the two groups (P>0.05), and there was also no significant difference in the incidence rates of the clinical symptoms such as cough, expectoration, and fever between the two groups (P>0.05). No significant difference was found between the two groups in leukocyte count, lymphocyte percentage, alanine aminotransferase, and serum creatinine (P>0.05). Compared with the unvaccinated group, the vaccinated group had significantly lower levels of aspartate aminotransferase, lactate dehydrogenase, and creatine kinase-MB (P<0.05). There was no significant difference between the two groups in the proportion of children with elevated C-reactive protein or procalcitonin and the levels of peripheral blood cytokines (P>0.05). The vaccinated group had significantly lower counts of B lymphocytes and total T lymphocytes (CD3⁺) than the unvaccinated group (P<0.05). Compared with the unvaccinated group, the vaccinated group had a significantly higher positive rate of IgG on admission and at week 2 of the course of disease (P<0.05), as well as a significantly higher Ct value of nucleic acid at weeks 1 and 2 of the course of disease (P<0.05). CONCLUSIONS Vaccination with inactivated SARS-CoV-2 vaccine may reduce myocardial injury caused by SARS-CoV-2 Delta variant. For children with SARS-CoV-2 Delta variant infection after the vaccination, more attention should be paid to their immune function.
COVID-19/prevention & control* ; COVID-19 Vaccines ; Child ; Humans ; Retrospective Studies ; SARS-CoV-2 ; Vaccination