Effectiveness of Inactivated COVID-19 Vaccines against Delta-Variant COVID-19: Evidence from an Outbreak in Inner Mongolia Autonomous Region, China.

Phase 3 clinical trials and real-world effectiveness studies showed that China's two main inactivated COVID-19 vaccines are very effective against serious illness. In November 2021, an outbreak occurred in the Inner Mongolia Autonomous Region that provided an opportunity to assess the vaccine effectiveness (VE) of these inactivated vaccines against COVID-19 caused by the delta variant. We evaluated VE with a retrospective cohort study of close contacts of infected individuals, using a generalized linear model with binomial distribution and log-link function to estimate risk ratios (RR) and VE. A total of 8842 close contacts were studied. Compared with no vaccination and adjusted for age, presence of comorbidity, and time since last vaccination, full vaccination reduced symptomatic infection by 62%, pneumonia by 64% and severe COVID-19 by 90%; reductions associated with homologous booster doses were 83% for symptomatic infection, 92% for pneumonia and 100% for severe COVID-19. There was no significant decline in two-dose VE for any outcome for up to 325 days following the last dose. There were no differences by vaccine brand. Inactivated vaccines were effective against delta-variant illness, and were highly effective against pneumonia and severe COVID-19; VE was increased by booster doses.

Informal learning during the standardized residency training in the context of “Internet plus:" an empirical research (preprint)

Background Informal learning refers to learners-sponsored, monitored and regulated learning method, which lays the foundation for medical life-long education of residents with sustainable self-learning ability and permanent learning behaviors. In this article the authors explore the academic value and significance in informal learning to improve the effectiveness for the standardized residency training in the context of “Internet plus” which combines technology with education to promote reforms for learning patterns. Standardized residency training started relatively late in China and there are less empirical studies targeted for the medical students in this phase. Based on it, this study aims to explore online informal learning behavior of medical students in residency training.Methods An empirical study was performed at the Fourth Hospital of Hebei Medical University in China where postgraduate medical education is being conducted. The study was implemented by questionnaire of the following aspects related to informal learning of residents as learning attitude, motivation, behavior and utilization of learning resources. Learning efficiency before and during COVID-19 is specifically surveyed and analyzed. 451 valid samples were collected to understand the situation of informal learning in the context of “Internet plus” and to find out interconnections among variables. The data from questionnaire has been analyzed through descriptive analysis, difference analysis and correlation regression analysis.Results Informal learning attitudes of residents in standardized training are of high recognition and strong learning belief but need better self-management; The intervention between informal learning motivation and behavior among the levels of self-control, learning target and utilization of online resources resulting in great influence of environmental and individual factors on self-efficacy. Relative weak ability appears in choosing, screening and utilizing effective information online without effective guidance from teachers.Conclusions In this study we innovatively propose appropriate and practical suggestions for researching methods in informal learning of postgraduate medical education in clinical setting during intensive online learning during COVID-19 period. The findings of this research have great significance in guiding learning paths, effects and development for informal learning of residents and put forward effective measures for the development of positive and sustainable informal learning in future career of the doctors-to-be.

Pathogenic T cells and inflammatory monocytes incite inflammatory storm in severe COVID-19 patients

Pathogenic human coronavirus infections, such as severe acute respiratory syndrome CoV (SARS-CoV) and Middle East respiratory syndrome CoV (MERS-CoV), cause high morbidity and mortality1, 2 . Recently, a severe pneumonia-associated respiratory syndrome caused by a new coronavirus (SARS-CoV-2) was reported at December 2019 in the city Wuhan, Hubei province, China3, 4, 5, which was also named as pneumonia-associated respiratory syndrome (PARS)6 and can cause coronavirus disease 2019 (COVID-19) to seriously endanger human health. Up to 24th of February 2020, at least 77779 cases have been reported with 2666 fatal cases according to the report from China CDC. However, the immune mechanism that potential orchestrated acute mortality from COVID-19 patients is still unknown. Here we show that after the SARS-CoV-2 infection, CD4+ T lymphocytes are rapidly activated to become pathogenic T helper (Th) 1 cells and generate GM-CSF etc. The cytokines environment induces inflammatory CD14+CD16+ monocytes with high expression of IL-6 and accelerate the inflammation. Given that large amount of inflammatory cells infiltrations have been observed in lungs from severe COVID-19 patients7, 8, these aberrant pathogenic Th1 cells and inflammatory monocytes may enter the pulmonary circulation in huge numbers and play an immune damaging role to causing lung functional disability and quick mortality. Our results demonstrate that excessive non-effective host immune responses by pathogenic T cells and inflammatory monocytes may associate with severe lung pathology. Thus, we suggest that monoclonal antibodies targeting GM-CSF or interleukin 6 may be effective in blocking inflammatory storms and, therefore, be a promising treatment of severe COVID-19 patients