Background: The second wave of the coronavirus disease 2019 (COVID-19) epidemic in India was caused by the COVID-19 Delta variant. However, the epidemiological characteristics and transmission mechanism of the Delta variant remain unclear. To explore whether the epidemic trend will change after effective isolation measures were taken and what is the minimum number of individuals who need to be vaccinated to end the epidemic.Methods: We used actual data from March 5 to April 15, 2021, of daily updates confirmed cases and deaths, to estimate the parameters of the model and predict the severity of possible infection in the coming months. The classical Susceptible-Exposed-Infected-Removed (SEIR) model and extended models [Susceptible-Exposed-Infected-Removed-Quarantine (SERIQ) model and Susceptible-Exposed-Infected-Removed- medicine (SERIM) model] were developed to simulate the development of epidemic under the circumstances of without any measures, after effective isolation measures were taken and after being fully vaccinated.Results: The result demonstrated good accuracy of the classic model. The SEIRQ model showed that after isolation measures were taken, the infections will decrease by 99.61% compared to the actual number of infections by April 15. And the SEIRQ model demonstrated that if the vaccine efficative rate was 90%, when the vaccination rate was 100%, the number of existing cases would reach a peak of 529,723 cases on the 52nd day.Conclusion: Effective quarantine measures and COVID-19 vaccination from official are critical prevention measures to help end the COVID-19 pandemic.

Animal studies have shown that capsaicin plays a positive role in weight management. However, the results in human research are controversial. Therefore, the present systematic review and meta-analysis aimed to evaluate the effect of capsaicin on weight loss in adults. We searched PubMed, Embase, China Biomedical Literature Database (CBM), Cochrane library and clinical registration center, identifying all randomized controlled trials (RCTs) published in English and Chinese to May 3, 2022. A random effect model was used to calculate the weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I 2 ). Statistical analyses were performed using STATA version 15.1. P <0.05 were considered as statistically significant. From 2377 retrieved studies, 15 studies were finally included in the meta-analyses. Fifteen RCTs with 762 individuals were included in our meta-analysis. Compared with the control group, the supplementation of capsaicin resulted in significant reduction on body mass index (BMI) (WMD: -0.25 kg/m2, 95%CI=-0.35∼-0.15 kg/m2, P<0.05), body weight (BW) (WMD: -0.51 kg, 95%CI=-0.86∼-0.15 kg, P<0.05) and waist circumference (WC) (WMD: -1.12 cm, 95%CI=-2.00∼-0.24 cm, P<0.05). We found no detrimental effect of capsaicin on waist-to-hip ratio (WHR) (WMD: -0.05, 95%CI=-0.17∼0.06, P>0.05). The current meta-analysis suggests that capsaicin supplementation may have rather modest effects in reducing BMI, BW and WC for overweight or obese individuals.