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
Objective To establish a dynamic model of hand foot and mouth disease in Jiangsu Province, analyze the epidemic of hand foot and mouth disease in Jiangsu, predict the trend of this disease and simulate the effect of EV71 vaccination on the control of hand foot and mouth disease caused by EV71. Methods A compartmental model of hand foot and mouth disease was constructed.A group of differential equations was established. The incidence data of hand foot and mouth disease was used to fit the model and calculate the basic reproduction number of this disease in Jiangsu. Then, vaccination was added to the model and the incidence of hand foot and mouth disease under different vaccination coverage rates was simulated. Results The basic reproduction numbers of hand foot and mouth disease in Jiangsu between 2013 and 2016 were 1.31 (IQR:0.99-1.48), 1.37 (IQR:0.97-1.52), 1.34 (IQR:1.00-1.61) and 1.38 (IQR:1.00-1.76) , respectively. With the increase of immunization coverage of EV71 vaccine, the cases of hand foot and mouth disease caused by EV71 decreased accordingly. When the annual immunization rate of EV71 vaccine was maintained at a high level (75%), the annual incidence of hand foot and mouth disease caused by EV71 after 5 years reduced to 10% of that in the same year when there was no vaccination. Conclusions The epidemic trend of hand foot and mouth disease in Jiangsu is stable from 2013 to 2016. Vaccination plays an important role in controlling hand foot and mouth disease caused by EV71.