Beijing Center for Disease Prevention and Control

Resilient health systems have been demonstrated to be important in safeguarding global health security against crises. However, health system resilience against infectious disease outbreaks is not well understood because of the ambiguity in the details of the conceptualization, and lack of evidence on the specific capacities that health systems need to be resilient to infectious disease outbreaks. We aimed to provide a detailed understanding of health system resilience against large-scale outbreaks by exploring the relevant factors and clarifying the correlations among them based on empirical evidence. We conducted a qualitative study comprising interviews with key informants in fields related to infectious disease prevention and control from different levels of the health system in China (n = 31). We formed an initial theoretical model for interviews and analysis based on classic models of resilience and theories of infectious disease prevention and control. The experiences of key informants during COVID-19 were explored to collect empirical evidence. The interview data was analyzed to extract resilience-related factors using a hybrid approach of thematic analyses. The complex adaptive system was used to explain the complex correlations of factors during large-scale outbreaks. Five dimensions representing the antecedent condition, capacity, and improvement that impact health system resilience against COVID-19 pandemic were extracted: socio-demographic, systems and contingency plans, inputs and reserves, decision-making and community engagement, and recovery and feedback. These dimensions were categorized into 19 resilience-related factors in detail. These factors play different roles during infectious disease prevention and control, leading to outcomes and impact of large-scale outbreaks. A theoretical model was also developed to provide insight into the relationship of these factors and their roles in health system resilience against large-scale infectious disease outbreaks. Factors of antecedent condition, capacity, and improvement have an impact on health system resilience against large-scale outbreaks. More actions are needed for pandemic preparedness, outbreak control, reflection and feedback to enhance health system resilience. The resilience threshold concept should be calculated by quantitative research in the future.

Whether a booster dose of hepatitis B vaccine is necessary for adolescents remains controversial. We conducted a retrospective cohort study from the Immunization Information System and The National Notifiable Disease Reporting System to evaluate the impact of hepatitis B virus (HBV) vaccination programs (universal infant hepatitis B immunization and adolescent booster) on HBV infection. The vaccine effectiveness (VE) of hepatitis B vaccine is 64.43% (95% CI 57.78% - 71.08%) within 10 years of birth, escalates to 95.36% (95% CI 94.84% - 95.88%) by 20 years, and decreases to 67.35% (95% CI 63.86% - 70.85%) by 30 years. Compared with Beijing's birth-vaccinated-only group, the booster group showed a lower relative VE in the first 10 years but a slight increase thereafter. Compared with the national control group, the booster group maintained a relatively high relative VE with a smaller decline magnitude. This study demonstrates that adolescent HBV booster vaccination administered during junior high school improves hepatitis B surface antibody levels and contributes to a further reduction in the incidence of HBV infection.

In crop protection, two major challenges persist: the insufficient deposition of agrochemicals on target plants (such as foliar runoff and excessive migration in soil) and the environmental risks of conventional non-degradable carriers. Here, a degradable polyester, poly(β-amino ester) (PAE), was synthesized via Michael addition and employed for the first time in agrochemical nanodelivery. Difenoconazole-loaded nanoparticles (215 nm, 32.5% loading) exhibited strong foliar adhesion, reduced soil migration, and enhanced photostability, thereby minimizing fungicide losses in both foliar spraying and soil application. The proton-sensitive amines in PAE enabled acid-responsive release matched to the acidic microenvironments of fusarium crown rot infection sites, while the intrinsic bioactivity of PAE provided synergistic antifungal effects. Pot experiments confirmed superior and prolonged control, achieving 51.2% disease suppression at 21 days compared with 32.7% for a commercial formulation. Biosafety evaluations demonstrated compatibility with wheat, reduced acute toxicity to earthworms, and environmentally benign degradation products. This study establishes a sustainable nanodelivery strategy that integrates degradability, pH-responsiveness, and dual adhesion into a single polyester platform. By enhancing fungicide utilization while reducing ecological risks, it highlights the potential of degradable polymers to advance cleaner and more effective management of soil-borne diseases. © 2025 Society of Chemical Industry.

ABSTRACT Background In China, low awareness of the herpes zoster vaccine (HZV) hinders vaccination uptake among older adults. This study aimed to investigate HZV awareness rates and associated factors among older urban Chinese adults to inform targeted interventions. Research design and methods A cross-sectional survey on the awareness of HZV was conducted from December 2024 to January 2025 among adults aged ≥60 years in 6 cities of China. Univariate and multivariable logistic analyses were performed to evaluate the factors related to the rate of awareness of HZV, including the interaction between income and education. Results The overall awareness rate was low at 43.4%. Awareness was significantly associated with self-reported health status, monthly income, educational level, and preretirement occupation (all p < 0.05). A significant synergistic effect was observed, where individuals with both high education and high income demonstrated markedly higher awareness levels. Conclusions The awareness of HZV among older adults in urban China is inadequate and inequitably distributed. Significant disparities in awareness, which were linked to socioeconomic status and occupational history, were identified. These findings pinpoint specific, underserved populations that should be prioritized for targeted health education strategies to bridge the knowledge gap and promote informed decision-making regarding HZ vaccination.

Hepatitis B virus (HBV) exhibits significant genetic diversity affecting clinical outcomes and interventions. Utilizing 4326 HBsAg-positive samples from China's 2020 national serosurvey (91 896 participants), we successfully sequenced S genes from 3311 specimens. Genotypes/subgenotypes were determined through maximum likelihood phylogeny; serotypes followed Purdy's method. Demographic, serological, and regional associations were analyzed by chi-square tests. Five HBV genotypes were identified: B (63.91%), C (22.80%), CD (10.48%), D (2.45%) and I (0.36%), plus 15 subgenotypes (B2 dominant, 61.73%). Four serotypes emerged: adw (60.65%), adr (24.37%), ayw (14.53%), and ayr (0.33%), with 10 subserotypes (adw2 dominant, 58.86%). Genotype B predominated East/Central/South China; C prevailed in North/Northeast China. Southwest/Northwest China showed co-circulation, with CD predominant in Southwest and D in Northwest China. B2 comprised 96.60% of genotype B; adw2 represented 97.06% of adw. Genotype distribution showed significant regional variation and strong associations with gender, age, ethnicity, serological profile, viral load, and serotype (all p < 0.05). HBV in China exhibits marked genetic heterogeneity characterized by distinct regional and population patterns. These findings underscore the necessity for tailored prevention strategies and optimized diagnostics/vaccines to address region-specific HBV diversity.

Objective:This study aims to evaluate the applicability and limitations of the equal energy hypothesis (EEH) in assessing noise-induced hearing loss (NIHL) and investigate the role of the kurtosis parameter (reflecting noise temporal structure) in assessing NIHL, providing a basis for refining EEH theory.Materials and Methods:A systematic review and meta-analysis were conducted to summarize studies related to EEH, systematically collecting its development, validation, and revision suggestions. The weighted mean difference (WMD) and odds ratio (OR) of hearing loss caused by different types of noise were used to evaluate the role of noise kurtosis in the evaluation of NIHL.Results:A total of 57 articles were included, containing experimental and cross-sectional studies. Evidence showed significant limitations in the EEH when assessing non-steady noise, leading to an underestimation of NIHL under equal energy conditions. Animal experiments verified a critical level for assessing NIHL when using the EEH, with ranges of 90–135 dB in chinchillas and 108–120 dB in guinea pigs. EEH could be revised in the frequency domain (spectrum) and time domain (e.g., kurtosis). Meta-analysis showed that in animal experiments, WMD for permanent threshold shifts (PTSs) at 2, 4, and 8 kHz (PTS at 2, 4, and 8 kHz) was 3.30 dB (95% confidence interval [95% CI]: 2.22–4.37); in population surveys, OR for high-frequency NIHL was 1.78 (95% CI: 1.36–2.32). Logistic regression analysis confirmed kurtosis as a risk factor for NIHL (P < 0.001). Kurtosis adjustment for cumulative noise exposure and equivalent sound level adequately improved the accuracy of hearing loss estimation.Conclusion:The EEH’s limitations in assessing NIHL caused by non-steady noise can be remedied by adjusting noise energy metrics using kurtosis. Our findings suggest that EEH could be revised as an “equal energy and equal kurtosis hypothesis.”

The immunological properties of recombinant hepatitis B surface antigen (rHBsAg), prepared using yeast (Saccharomyces cerevisiae [SC]) and Chinese hamster ovary (CHO) cells, were evaluated through in vitro and invivo assays to support the efficacy of recombinant hepatitis B vaccines. In vitro, antigenicity was assessed by measuring the affinity of rHBsAg to anti-HB antibodies using surface plasmon resonance. In vivo, mice were intraperitoneally injected with 3 µg of simulated vaccines containing anti-HB antibodies absorbed onto aluminum hydroxide adjuvant. Humoral responses were evaluated by measuring serum anti-HB antibody titers and seroconversion rates on days 7, 14, 21, and 28. Cellular immune responses were assessed based on cytokine (Interferon-γ-IFN-γ) and (Tumor Necrosis Factor-α- TNF-α) production from splenic lymphocytes on day 28 postimmunization. A recombinant Huh-7-HBsAg cell line, developed to analyze cellular immune responses, was established through cytotoxicity and apoptosis assays. In vitro, the equilibrium dissociation constant (KD) of rHBsAg from CHO cells was significantly lower than that from yeast cells, indicating stronger antibody affinity. In vivo, rHBsAg-CHO induced faster and higher antibody titers compared with rHBsAg-SC. Cellular responses showed higher levels of TNF-α and IFN-γ for rHBsAg-CHO. In addition, the rHBsAg-CHO group exhibited higher late apoptosis rates in target cells. The rates induced in the rHBsAg-CHO and rHBsAg-SC groups were 25.0% and 19.2%, respectively. In conclusion, this study demonstrates that the immunological properties of rHBsAg vary based on the expression systems and provides nonclinical data supporting the evaluation of vaccine efficacy.

BackgroundThe global outbreak of mpox that began in 2022 caused sustained human-to-human transmission and demonstrates distinct epidemiological characteristics compared to previous outbreaks. Our aim is to quantify temporal variation of mpox transmissibility within or between age groups and evaluate the effectiveness of interventions in real time.MethodsThe data used in this study is sourced from publicly available mpox confirmed cases data provided by WHO. We divided population into four age groups and constructed a transmission dynamics model with age structure of the population. And we estimated the transmissibilities of the monkeypox virus within or between age groups in real time by assimilation of global surveillance data from WHO, and performed intervention simulations in different scenarios we set up.ResultsThe effective reproduction number of mpox in the 18–44 age group is significantly higher than in other age groups, and it initially experiences a rapid increase, enters a phase of steady decrease after reaching a certain point [{R}_{22}=1.33, 95% credible interval (CrI): 1.10–1.56]. Earlier implementation of interventions yields both superior effectiveness and greater cost-efficiency. Emergency vaccination for whole population initiated on June 15, 2022 reduced cumulative infections by 67.43% (95% CrI: 62.15–72.71) at only 40% coverage, whereas vaccination starting August 1, 2022 achieved only 47.86% (95% CrI: 42.70–53.01) reduction at 90% coverage. And high-risk-targeted and population-wide interventions showed limited effectiveness differences. Case management (3-day mean infectious period) initiated on July 15 achieved cumulative infection reductions of 59.84% (95% CrI: 54.28–65.40) when targeting the whole population, compared to 56.80% (95% CrI: 49.24–64.35) reduction when targeting only high-risk groups (aged 18–44 years).ConclusionsThe transmissibility of mpox within the 18–44 age group follows a distinct pattern of rapid growth—slow decline not observed to the same extent in other age groups. Real-time estimation of mpox transmissibility within or between age groups helps us to understand the dynamic process of mpox interpersonal transmission better and evaluate the effect of various interventions in real world more promptly.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s40249-025-01369-7.