ABSTRACT
With the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, the importance of vaccines in epidemic prevention and public health has become even more obvious than ever. However, the emergence of multiple severe acute respiratory syndrome coronavirus 2 variants worldwide has raised concerns about the effectiveness of current COVID-19 vaccines. Here, we review the characteristics of COVID-19 vaccine candidates in five platforms and the latest clinical trial results of them. In addition, we further discuss future directions for the research and development of the next generation of COVID-19 vaccines. We also summarize the serious adverse events reported recently after the large-scale vaccination with the current COVID-19 vaccines, including the thromboembolism caused by the AstraZeneca and Johnson & Johnson vaccines.
Subject(s)
Humans , COVID-19 , COVID-19 Vaccines , SARS-CoV-2 , VaccinesABSTRACT
To evaluate the effectiveness of live attenuated influenza vaccine (LAIV) in the prevention of seasonal influenza in children aged 2-17 years. Literature retrieval of case-control studies on the effectiveness of LAIV against seasonal influenza in children published from January 2003 to November 2018 was conducted through Web of Science, PubMed, and ScienceDirect databases. The Stata 13.1 software was used for Meta-analysis. A total of 14 studies were included in this study, and all were test-negative design (TND) studies. Our Meta-analysis showed that the effectiveness of LAIV in children was 49 (95: 40-57). Subgroup analysis found that the protection rate of LAIV was 35 against influenza A (H1N1) pdm09 (95: 5-56), 35 against influenza A (H3N2) (95: 21-46), and 71 against influenza B (95: 55-82). The protection rates of trivalent LAIV and quadrivalent LAIV in children were 56 (95: 48-63) and 44 (95: 27-57), respectively. The protection rates of LAIV in Europe and North America were 65 (95: 47-77) and 46 (95: 36-55), respectively. LAIV has a certain preventive effect on seasonal influenza in children aged 2-17 years.