Background The enterovirus 71 (EV-A71) vaccine has been used in Hefei for several years, and the epidemiological significance of vaccination in this area is unclear. We aims to explore the spatial–temporal-demographic and virological changes of hand, foot and mouth disease (HFMD) after vaccination in China. Methods The data for HFMD from 2012 to 2020 were downloaded with the help of HFMD reporting system of Hefei Center for Disease Control and Prevention and combined with the EV-A71 vaccination status in Hefei. The study defined the period between 2012 to 2016 as the pre-vaccination period and explored the effect of vaccination on the incidence of HFMD by comparing the changes of HFMD before and after vaccination in terms of spatial, temporal, demographic and virological aspects. Results During the study period, a higher incidence occurred in urban area and the random distribution changed to a slight cluster after vaccination. HFMD incidence had inconsistent seasonality over years, with one or two incidence peaks in varying years. The morbidity decreased from 215.22/105 in 2012–2016 to 179.81/105 in 2017–2020 (p < 0.001). Boys, 0–4 years old children and Scattered children were more susceptible to HFMD compared with the others, the proportions decreased after vaccination except in Scattered children. The main pathogenic enterovirus gradually changed from EV-A71 to Other Enteroviruses, especially coxsackieviruses A6 (CV-A6) after the implementation of EV-A71 vaccination. Conclusions The EV-A71 vaccine was effective in reducing the incidence of HFMD and changing the spatial, temporal, demographic, and virological characteristic. These changes should be considered during the vaccination implementation to further reduce the disease burden of HFMD.

Recommended treatment regimen for human immune deficiency virus (HIV) infection includes protease inhibitors/ritonavir (PIs/r) combined with twonucleoside reverse-transcriptase inhibitors (2NRTIs), which enable to achieve and maintain viral suppression, restore, and preserve immune function. However, there were inconsistent findings on the levels of interleukin-6 (IL-6) levels. Systematic review and meta-analysis were performed to quantify the pooled effects of PIs/rbased antiretroviral therapy (ART) on serum/plasma IL-6 levels in people living with the HIV (PLHIV). PubMed, Web of Science, and Embase were searched from the earliest record to November 4, 2020. Data analysis was conducted on Stata version 16 and Review Manager 5.3. A random-effect model was used to compute a pooled effect size and weighted mean difference (WMD) was considered the summary effect size. Heterogeneity between studies was estimated by Cochrane's Q test (χ 2 test) and I 2 statistic and subgroup analysis were performed to explore the source of heterogeneity. Initial search identified 3098 records and 5 studies (7 trials) met inclusion criteria. The pooled mean difference in serum/plasma IL-6 levels from baseline to follow-up was 0.534 pg/ml (95% confidence interval: −0.012, 1.08, P = 0.05, I 2 = 76.4%). In subgroup analysis, there was a significant association between increased serum/plasma IL-6 levels and age group ≥ 35 years old, baseline CD4 + counts < 350 cell/mm 3 , and mean viral load ≥ 4.5 log10 copies/ml. We found that serum/plasma IL-6 levels increased after combined ART among treatment-naïve individuals who initiated a successful combination of PIs/r with 2NRTIs. This result also highlights the need to monitor serum/plasma IL-6 levels during antiviral therapy, which may aid in the effective future treatment of systemic inflammation and related disorders following elevated IL-6 levels.