Background: COVID-19 is a pandemic with no specific antiviral treatments or vaccines. The urgent needs for exploring the neutralizing antibodies from patients with different clinical characteristics are emerging. Methods: A total of 117 blood samples were collected from 70 COVID-19 inpatients and convalescent patients. The presence of neutralizing antibody was determined with a modified cytopathogenic assay based on live SARS-CoV-2. The dynamics of neutralizing antibody levels at different with different clinical characteristics were analyzed. Results: The seropositivity rate reached up to 100.0% within 20 days since onset, and remained 100.0% till day 41-53. The total GMT was 1:163.7 (95% CI, 128.5 to 208.6), and the antibody level was highest during day 31-40 since onset, and then decreased slightly. Individual differences in changes of antibody levels were observed among 8 representative convalescent patients. In multivariate GEE analysis, patients at age of 31-60 and 61-84 had a higher antibody level than those at age of 16-30 (β=1.0518, P =0.0152; β=1.3718, P =0.0020). Patients with a worse clinical classification had a higher antibody titer (β=0.4639, P =0.0227). Conclusions: The neutralizing antibodies were detected even at the early stage of disease, and a significant response showed in convalescent patients. Moreover, changes on antibody levels ware individual specific.

Norovirus (NoV) is a leading cause of sporadic cases and outbreaks of acute gastroenteritis (AGE). Increased NoV activity was observed in Beijing, China during winter 2014–2015; therefore, we examined the epidemiological patterns and genetic characteristics of NoV in the sporadic cases and outbreaks. The weekly number of infectious diarrhea cases reported by all hospitals in Beijing was analyzed through the China information system for disease control and prevention. Fecal specimens were collected from the outbreaks and outpatients with AGE, and GI and GII NoVs were detected using real time reverse transcription polymerase chain reaction. The partial capsid genes and RNA-dependent RNA polymerase (RdRp) genes of NoV were both amplified and sequenced, and genotyping and phylogenetic analyses were performed. Between December 2014 and March 2015, the number of infectious diarrhea cases in Beijing (10,626 cases) increased by 35.6 % over that of the previous year (7835 cases), and the detection rate of NoV (29.8 %, 191/640) among outpatients with AGE was significantly higher than in the previous year (12.9 %, 79/613) (χ 2 = 53.252, P < 0.001). Between November 2014 and March 2015, 35 outbreaks of AGE were reported in Beijing, and NoVs were detected in 33 outbreaks, all of which belonged to the GII genogroup. NoVs were sequenced and genotyped in 22 outbreaks, among which 20 were caused by a novel GII.17 strain. Among outpatients with AGE, this novel GII.17 strain was first detected in an outpatient in August 2014, and it replaced GII.4 Sydney_2012 as the predominant variant between December 2014 and March 2015. A phylogenetic analysis of the capsid genes and RdRp genes revealed that this novel GII.17 strain was distinct from previously identified GII variants, and it was recently designated as GII.P17_GII.17. This variant was further clustered into two sub-groups, named GII.17_2012 and GII.17_2014. During winter 2014–2015, GII.17_2014 caused the majority of AGE outbreaks in China and Japan. During winter 2014–2015, a novel NoV GII.17 variant replaced the GII.4 variant Sydney 2012 as the predominant strain in Beijing, China and caused increased NoV activity.

Introduction: Enterovirus A71(EV-A71)-associated hand, foot, and mouth disease (HFMD) has been reported worldwide, and poses a particularly heavy burden on patients, families, and society in China. Three Chinese companies have licensed inactivated EV-A71 vaccines, all of which have demonstrated good efficacy for preventing EV-A71-associated disease in clinical trials. However, real-world performance of EV-A71 vaccine has not been evaluated. Methods: We used a test-negative design case-control study to estimate vaccine effectiveness (VE) against medically attended EV-A71-associated HFMD. Subjects were children 5 years of age and under who had been in health facilities participating in the HFMD case and virologic surveillance platforms in Beijing. Enterovirus infections were laboratory confirmed, and EV-A71 vaccination status was extracted from electronic immunization records. Children testing positive for EV-A71 were cases; controls were children testing negative for EV-A71 infection. Logistic regression was used to estimate VE. We assessed sensitivity of VE estimates to control group inclusion criteria by repeating the regression analyses with two alternative control groups. Results: A total of 2,184 HFMD patients aged 5 years and under were enrolled in the study; 24 were severe, and 2,160 were mild. For severe cases, two-dose VE estimate was 100% (95% CI: −68.1%, 100%). For mild cases, 1-dose and 2-dose adjusted VE estimates were 69.8% and 83.7%, respectively. Two-dose VE estimates varied by less than 4 percentage points regardless of control group definition. Conclusions: Our findings suggested the vaccines performed well in the real world for children 5 years of age and under in Beijing, China.

There are substantial differences between the costs of medical masks and N95 respirators. Cost-effectiveness analysis is required to assist decision-makers evaluating alternative healthcare worker (HCW) mask/respirator strategies. This study aims to compare the cost-effectiveness of N95 respirators and medical masks for protecting HCWs in Beijing, China. We developed a cost-effectiveness analysis model utilising efficacy and resource use data from two cluster randomised clinical trials assessing various mask/respirator strategies conducted in HCWs in Level 2 and 3 Beijing hospitals for the 2008–09 and 2009–10 influenza seasons. The main outcome measure was the incremental cost-effectiveness ratio (ICER) per clinical respiratory illness (CRI) case prevented. We used a societal perspective which included intervention costs, the healthcare costs of CRI in HCWs and absenteeism costs. The incremental cost to prevent a CRI case with continuous use of N95 respirators when compared to medical masks ranged from US $490–$1230 (approx. 3000-7600 RMB). One-way sensitivity analysis indicated that the CRI attack rate and intervention effectiveness had the greatest impact on cost-effectiveness. The determination of cost-effectiveness for mask/respirator strategies will depend on the willingness to pay to prevent a CRI case in a HCW, which will vary between countries. In the case of a highly pathogenic pandemic, respirator use in HCWs would likely be a cost-effective intervention.

Introduction: The resurgence of measles, a highly contagious infectious disease, has become a serious global public health issue. In this study, we aimed to explore global spatial–temporal measles trends and the underlying causes to help formulate effective intervention strategies. Methods: We analysed measles incidence data from 192 countries, integrating measles vaccination coverage from WHO/UNICEF Estimates of National Immunization Coverage, armed conflict data from the Uppsala Conflict Data Program and gross domestic product (GDP) per capita and population data from the World Bank’s World Development Indicators. Hot spot analysis, mean centre and standard deviational ellipse models were used to examine the geographic and temporal shifts in measles outbreaks. A negative binomial mixed‐effects model was then constructed to determine the influence of population size, GDP per capita, measles vaccine coverage and armed conflict on measles incidence. Results: Our findings showed a pronounced southward shift in measles outbreaks from Southeast Asia to sub-Saharan Africa between 2018 and 2019, followed by a northward progression towards Europe from 2019 to 2023. The negative binomial model indicated that armed conflict significantly increased measles incidence (estimate=1.131, p<0.05) and that higher second dose of measles vaccine (MCV2) coverage reduced incidence (estimate=–0.052, p<0.05). Additionally, regions with lower GDP per capita experienced elevated measles burdens, reflecting resource constraints and diminished vaccination infrastructure. Conclusions: Ensuring robust two-dose vaccination coverage, particularly for MCV2, remains critical for reducing measles incidence worldwide. These results underscore the importance of tailored interventions, especially in conflict‐affected and lower‐income regions. Enhanced spatiotemporal surveillance and targeted public health initiatives can help address both the direct impact of armed conflict on health systems and the broader socioeconomic drivers that facilitate measles outbreaks.