BACKGROUND:Data on influenza vaccine effectiveness (VE) against hospitalized severe acute respiratory infection (SARI), particularly in Asia, remain limited for the 2025/26 Northern Hemisphere influenza season. This study aimed to evaluate real-world VE against A(H3N2)-associated SARI hospitalization and provide timely, locally relevant evidence to inform seasonal influenza vaccination policy. METHODS:A test-negative design was used to estimate VE against influenza A(H3N2)-associated SARI hospitalization in Beijing, China, from 10 November 2025 to 18 January 2026. VE was estimated by comparing the odds of influenza vaccination between case-patients (those who tested positive for A(H3N2)) with controls (those who tested negative for influenza). RESULTS:Among 1883 enrolled SARI inpatients, 220 (11.7%) tested positive for influenza A(H3N2). Overall vaccination coverage was 11.4%, with the highest coverage observed among children aged 5-17 years (29.6%). Influenza positivity was higher among rural residents, patients with pneumonia or hypoxemia, and those with symptom onset in November. The adjusted overall VE was 7.5% (95% CI: -45.8% to 43.3%). Moderate VE was observed among children aged 5-17 years (45.4%, 95% CI: -33.6% to 79.5%), although the confidence interval included zero and the estimate was not statistically significant. Negative VE estimates were observed among younger children and older adults. Among patients with underlying respiratory conditions, VE was 75.4% (95% CI: -27.4% to 98.7%), although this estimate was also not statistically significant. CONCLUSIONS:During the 2025/26 influenza season in Beijing, VE against A(H3N2)-associated SARI hospitalization was suboptimal. Moderate protection was observed among children aged 5-17 years, the group with the highest vaccination coverage, but the estimate was not statistically significant. The low overall VE may be attributable to antigenic mismatch between vaccine and circulating strains, as well as low population-level vaccination coverage. These findings highlight the need to improve vaccine formulations and increase vaccination coverage, particularly among adults and older populations.

BACKGROUND:Hand, foot, and mouth disease (HFMD), particularly EV-A71, has caused large-scale epidemics in the Asia-Pacific region, with China alone reporting over 2 million annual cases and causing a substantial morbidity and mortality. While EV-A71 vaccination was introduced in 2016 and COVID-19 non-pharmaceutical interventions (NPIs) were implemented from 2020-2022, comprehensive evidence on their independent and combined effects on HFMD epidemiology remains scarce. We aimed to quantify the impact of vaccination, NPIs, and post-pandemic policy relaxation on HFMD incidence and pathogen distribution. METHODS:We conducted an interrupted time series segmented regression analysis using a 14-year surveillance dataset (January 2011-December 2024) from Beijing's National Notifiable Disease Reporting System and citywide pathogen surveillance network. The study population included all HFMD cases reported in Beijing. We defined four intervention periods: baseline (pre-vaccination), vaccination introduction (August 2016), stringent NPIs (January 2020), and reopening (January 2023). Primary outcomes were HFMD incidence rates and incidence rate ratios (IRRs). We estimated prevented cases under counterfactual scenarios. RESULTS:Among 324,623 reported HFMD cases across the 14-year study period, interrupted time series regression demonstrated that vaccination was associated with a 33% reduction in incidence (IRR 0.67, 95% CI: 0.49-0.91); cumulatively over 8 years (2016-2024), this was estimated to have prevented 23.8% of cases that would have occurred without vaccination. Stringent NPIs were associated with an 84% reduction (IRR = 0.16, 95% CI: 0.06-0.41); cumulatively, during the intervention period (2020-2022), NPIs were estimated to have prevented 82.6% of cases. Following policy relaxation, incidence rebounded 2.53-fold (95% CI: 0.64-9.92), although this increase did not reach statistical significance. In absolute terms, monthly mean case counts declined from 3001 (baseline) to 1886 following vaccination introduction (37.2% decrease), and further to 299 during stringent NPIs (90.0% decrease from baseline), before surging to 1503 post-reopening, a fivefold increase from the NPI period. Pathogen surveillance revealed EV-A71 prevalence declined from 30.5% (baseline) to 4.5% (vaccination period), while coxsackievirus A6 emerged as the dominant serotype, from 9.5% (baseline period) to 56.2% (vaccination period). CONCLUSIONS:EV-A71 vaccination and NPIs were each associated with reduced HFMD transmission, but policy relaxation was followed by a substantial resurgence. The observed serotype replacement with non-vaccine-type enteroviruses highlight critical gaps in current prevention strategies. Sustaining HFMD control requires optimizing vaccine design, developing multivalent vaccines, maintaining high coverage, and integrating targeted NPIs during high-transmission seasons.

Toxigenic Vibrio cholerae (V. cholerae) was first sensitively and rapidly detected in hospital wastewater in Beijing, China, on 12 June 2025. Viable V. cholerae was successfully isolated from the wastewater sample and identified as the O1 Ogawa serotype. Whole-genome sequencing and comparative genomic analysis revealed that the isolate was closely related to locally circulating strains but clearly distinct from the seventh pandemic lineage, suggesting its link to indigenous transmission chains. In addition, we immediately initiated a comprehensive and multi-source traceback investigation upon detection of this positive signal, integrating clinical, environmental, and epidemiological data. This case highlights the early-warning and situational-awareness value of wastewater surveillance in detecting emerging pathogens and emphasizes its indispensable role in infectious disease prevention and control systems, providing a scientific basis for timely public health decision-making.

ObjectiveTo establish an adjusted Serfling regression model to estimate the excess cases and the excess epidemic period of hand-foot-mouth disease (HFMD) in Beijing from 2011 to 2019, so as to provide data support and decision-making basis for HFMD prevention and control.MethodsThe weekly number of HFMD cases in Beijing from 2011 to 2019 was utilized for adjusted the Serfling regression model. Then the adjusted model was used to fit the baseline and epidemic threshold of HFMD in Beijing from 2011 to 2019, calculating the excess cases and determining the excess epidemic period.ResultsA total of 279 306 cases of HFMD were reported in Beijing from 2011 to 2019, with the climax of the disease occurring in summer and autumn. After adjusting the fitting R2 of the Serfling regression model to 0.773, a total of 10 excess epidemic periods totaling 92 weeks were estimated, mainly occurring in summer. The highest number of excess cases during an excess epidemic period was found in 2014 (1 272 cases, 95%CI: 990‒1 554), accounting for 65.04% of the actual cases (95%CI: 50.62%‒79.46%).ConclusionThe adjusted Serfling regression model fits well and can be utilized for early warning of HFMD and estimating the disease burden caused by HFMD.

Introduction: The objective of our study was to estimate the influenza vaccine effectiveness for 2023/24 epidemic of co-circulating influenza A(H3N2) and B(Victoria) viruses in Beijing, China. Methods: The surveillance-based study included all swabbed patients through influenza virological surveillance in Beijing, between October 2023 and March 2024. A Test-Negative Design(TND) was used to estimate influenza vaccine effectiveness(VE) against medically- attended laboratory-confirmed influenza in outpatient settings, also calculated the influenza vaccination rate(IVR). Cases were influenza-like illness (ILI) patients who tested positive for influenza, and controls were ILI who influenza negative patients. Results: A total of 18,665 ILI patients were enrolled and swabbed. Among them, 6362(34.1 %) tested positive for influenza, major epidemic strain was A(H3N2) and B(Victoria). The overall IVR was 8.7 %, and the differences of IVR by gender, age, region, chronic conditions and month of onset were statistically significant(P<0.05). The adjusted VE against all influenza was moderate at 44.8 %, with the highest for B (Victoria) at 52.2 %, the highest for 19-59 age at 72.4 %, and the highest when vaccinated only in current season at 48.3 %. Conclusion: Our study suggested the influenza vaccine has moderate effectiveness, with the best VE against B (Victoria), followed by A(H3N2) and A(H1N1)pdm09 in Beijing, 2023/24 season. Meanwhile, the influenza VE was relatively high in school-age children and the elderly. Consistent long-term studies are required in the future to evaluate the protect effect of influenza vaccine.

The present study aimed to evaluate the vaccine effectiveness (VE) of different doses of an inactivated coronavirus disease 2019 (COVID-19) vaccine against Omicron BA.2.2 infection in Beijing, China, 2022. Based on data from a previous cohabitation retrospective cohort of COVID-19 outbreak in Beijing, China, 2022, the cohabitating contacts of individuals with BA.2.2 infection were followed up. Using a log-binomial regression model in which the unvaccinated group as the control group, the risk ratios of different doses of inactivated vaccine in terms of preventing SARS-CoV-2 infection, symptoms of COVID-19, and pneumonia were calculated, and the protective effect of the vaccine was estimated. The Kruskal–Wallis rank-sum test was used to compare the effect of vaccination on the viral load of infected patients. From April to June 2022, a total of 2259 cohabiting close contacts of 1308 patients with SARS-CoV-2 infection aged ≥3 years were included. Of the included close contacts, 737 (32.63%) were positive for SARS-CoV-2 during the isolation period: 140 (19.00%) were infected but asymptomatic, 525 (71.23%) had mild infection, and 72 (9.77%) had pneumonia. There were no cases of severe or critical infection or death. The VE of the primary in preventing BA.2.2 infection, symptoms, and pneumonia was 37.35% (95% CI: 24.00–48.35), 42.36% (95% CI: 28.41–53.60), and 48.35% (95% CI: −5.34–74.67), respectively. The VE of the booster shot in preventing SARS-CoV-2 infection, symptoms, and pneumonia was 37.08% (95% CI: 24.29–47.70), 44.38% (95% CI: 31.45–54.87), and 61.46% (95% CI: 29.79–78.85), respectively. Six months after the booster vaccination, the VE of the booster in terms of preventing SARS-CoV-2 remained above 46%, and its VE in terms of the prevention of pneumonia remained above 72%. In the unvaccinated group, the Ct values of the N gene and ORFlab gene (represented by the median value and Q1 and Q3 in parentheses) were 26.45 (21.09, 31.61) and 28.06 (22.21, 32.06), respectively. There was no significant difference in the median value of either gene between the unvaccinated group, the partial group [25.81 (19.91, 31.78) and 26.98 (21.63, 31.17)], the primary group [28.79 (22.08, 32.34) and 29.30 (23.81, 33.86)], and the booster group [26.23 (21.66, 31.46) and 27.73 (23.38, 32.52)] (p > 0.05). Inactivated COVID-19 vaccines provided a certain level protection from infection and symptoms, very good protection against pneumonia, and it still has a modest protective effect at 6 months after vaccination. Booster doses are necessary to provide strongest protection. However, irrespective of their vaccination status, individuals with COVID-19 have a similar viral load.

Objective:Infectious diseases controlling system is indispensable for weaken the damage to the people's life and property security caused by infectious diseases. An effective infectious diseases controlling system must incorporate an early warning mechanism designed to detect abnormal rising trends (outbreak) in spatial-temporal series. However, existing anomaly detection methods are often constrained by the quality and quantity of available data in specific application scenarios, particularly in infectious diseases early warning scenarios. Methods:The emergence of generative pre-trained large time series models-hereafter referred to as large time series models-may provide a solution to this challenge. Based on these models, we propose an effective early warning framework. Results:We compared the framework with statistic and deep learning methods on real-world infectious diseases datasets and related derived datasets. Our framework has a better performance and requires less data. Conclusion:We propose a readily deployable early warning framework characterized by strong generalization ability and exceptional performance, which would enlighten the epidemic modeling researchers.

This study aimed to estimate the end-of-season influenza vaccine effectiveness (VE) for the 2024/25 season in Beijing, China. Methods: We used a test-negative design (TND) to assess influenza VE among outpatients with influenza-like illness (ILI) enrolled through the influenza virological surveillance in sentinel hospitals in Beijing from week 44, 2024 to week 14, 2025. Cases were ILI patients who tested positive for influenza; controls were those who tested negative. Results: Among 18,405 ILI patients tested, 3690 (20.0%) were positive for influenza, with A(H1N1)pdm09 as the predominant strain (98.9%). The overall influenza vaccination coverage was 12.4%. Adjusted VE was 48.3% (95%CI: 40.4%–55.3%) against any influenza and 48.2% (95%CI: 40.3%–55.1%) against A(H1N1)pdm09, with the highest VE observed in adults aged 18–59 years (79.0%). The adjusted VE was similar for those vaccinated in 2023/24 only (53.1%) or both 2023/24 and 2024/25 seasons (50.8%), but lower for those vaccinated only in the 2024/25 season (48.5%). The adjusted VE was higher during the epidemic period (52.5%) than in the pre-epidemic (48.1%) and post-epidemic (35.3%) periods. Conclusions: Our findings indicate moderate VE against laboratory-confirmed influenza, especially A(H1N1)pdm09, during the end of the 2024/25 season in Beijing, China. Influenza vaccination provided protective effects across different epidemic periods. These timely estimates support ongoing public health communication and immunization strategies.

The study aimed to analyze epidemiological, clinical, and genome characteristics of acute gastroenteritis (AGE) outbreaks caused by sapovirus in Beijing. Epidemiological and clinical characteristics of sapovirus detected by RT-qPCR were collected from AGE surveillance. Descriptive statistics were used for epidemiological analysis, and both genotype identification and sequence analysis were conducted on the VP1 regions, RNA-dependent RNA polymerase regions, and whole genomes. From 2014 to 2021, sapovirus was the second most common pathogen in AGE outbreaks, causing 216 outbreaks (6.85%) with peaks in 2017, 2019, and 2021. The predominant outbreaks occurred in kindergartens (76.39%, 165) and primary schools (18.98%, 41) within urban (62.96%, 136) and suburban (35.19%, 76) by person-to-person transmission (97.73%, 172). Outbreaks in outer suburbs lasted longer duration [median 7 days, IQR: 6-8]. Comprehensive schools (21.62%, IQR: 10.00-35.00%) and kindergartens (18.18%, IQR: 13.51-22.72%) showed higher attack rates. Clinical symptoms included vomiting (97.27%, 1,462), diarrhea (18.44%, 277), fever (8.32%, 125), nausea (28.72%, 432), and abdominal pain (33.94%, 510). Vomiting prevalence was higher in children aged ≤5 years (96.94%, 983/1,014), while diarrhea prevalence was higher in those >5 years (31.29%, 153/489). Eight genotypes (GI.1-3, 5, 6; GII.1, 3, 5) were identified, and the predominant genotype changed from GII.3 (2016-2019) to GI.2 (2020-2021). Phylogenetic analysis revealed emerging clades in GII.3 and GI.2, with nucleotides and amino acids mutations confirmed by whole-genome sequencing. Therefore, sapovirus is a significant AGE pathogen in Beijing, China, warranting its inclusion in surveillance among sporadic cases and outbreaks of AGE in China with necessitating genotyping and whole-genome sequencing.

Background. To estimate effect of COVID-19 control measures taken to mitigate community transmission in many regions, we analyzed data based on influenza surveillance system in Beijing from week 27th, 2014 to week 26th, 2020. Methods. We collected weekly number of influenza-like illness (ILI), weekly positive proportion of ILI and weekly ILI proportion in outpatients and the date of COVID-19 measures. We compared influenza activity indicators of influenza season 2019/2020 with preceding five seasons and built two ARIMAX models to estimate the effective of COVID-19 measures. Results. Compared with preceding five influenza seasons, ILIs, positive proportion of ILI, and duration of influenza epidemic period decreased from 13% to 54%, especially, the number of weeks from the peak to the end of influenza epidemic period, decreased from 12 to one. After natural decline considered, weekly ILIs decreased by 48.6% and weekly positive proportion dropped 15% in the second week after emergency response declared, and finally COVID-19 measures reduced 83%. Conclusions. We conclude public health emergency response can interrupt the transmission of influenza and other respiratory infectious diseases markedly. Keyword. COVID-19 control measures; influenza; ARIMAX

AbstractWhile many countries employed digital contact tracing to contain the spread of SARS-CoV-2, the contribution of cospace-time interaction (i.e., individuals who shared the same space and time) to transmission and to super-spreading in the real world has seldom been systematically studied due to the lack of systematic sampling and testing of contacts. To address this issue, we utilized data from 2230 cases and 220,878 contacts with detailed epidemiological information during the Omicron outbreak in Beijing in 2022. We observed that contact number per day of tracing for individuals in dwelling, workplace, cospace-time interactions, and community settings could be described by gamma distribution with distinct parameters. Our findings revealed that 38% of traced transmissions occurred through cospace-time interactions whilst control measures were in place. However, using a mathematical model to incorporate contacts in different locations, we found that without control measures, cospace-time interactions contributed to only 11% (95%CI: 10%–12%) of transmissions and the super-spreading risk for this setting was 4% (95%CI: 3%–5%), both the lowest among all settings studied. These results suggest that public health measures should be optimized to achieve a balance between the benefits of digital contact tracing for cospace-time interactions and the challenges posed by contact tracing within the same setting.

Objective:To estimate the vaccine effectiveness (VE) of the seasonal influenza vaccination in prevention of hospitalized severe acute respiratory infection (SARI) in Beijing in the 2018/2019 epidemic season of influenza.Methods:Hospitalized SARI cases in 11 Beijing hospitals during 2018/2019 epidemic season of influenza were selected as study subjects. Vaccination status was determined from registry record system. Influenza virus infection was detected by RT-PCR. A binary logistic regression model was used to adjust influence from age, time of onset and underlying diseases to calculate the odds ratio (OR) between influenza virus nucleic acid positive and negative groups. VE was then calculated by 1-OR.Results:The overall estimated VE was -42.6% (95% CI: -152.7% to 19.5%) while VE of 5-59 group was 58.5% (-119.4% to 92.2%).VE of vaccination within 60 days was 15.8% (-142.8% to 70.8%). Conclusions:The protection effectiveness of influenza vaccine for hospitalized SARI patients in Beijing during 2018/2019 epidemic season of influenza were limited. Vaccination coverage in target groups should be enhanced.

Since the outbreak of COVID-19, countries and regions worldwide have implemented multifaceted prevention and control measures, including vaccinations, antiviral drugs, mask wearing, and social distancing. However, omicron variants, with significantly increased endogenous and occult transmission,

Objective:To analyze the characteristics of coronavirus disease 2019 (COVID-19) cluster epidemic caused by Omicron variant BA2.2 in Market A of Beijing, so as to provide reference for future epidemic prevention and control.Methods:The data of COVID-19 cases in Market A of Beijing in 2022 were collected, and the epidemiological characteristics were analyzed. Respiratory tract specimens were collected for nucleic acid detection by real-time RT-PCR and sequencing analysis.Results:From April 30 to May 10, 2022, a total of 53 COVID-19 cases were reported, including 42 confirmed cases (79.2%) and 11 asymptomatic cases (20.8%). There were 33 male cases (62.3%) and 20 female cases (37.7%). The age ranged from 20 to 68 years old with a median age of 44 years old. The shortest incubation period was 3.2 days and the secondary attack rate was 33.3%.Conclusions:The epidemic situation in the market was affected by the speed of investigation for the index case. After the market is sealed and controlled, measures such as centralized isolation should be taken as soon as possible to avoid greater transmission risk.

Objective:To explore the retention time and change pattern of the viral RNA of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant on the surfaces of different materials under different temperature, so as to provide a basis for the detection of SARS-CoV-2 on environmental samples and the formulation of relevant prevention and control strategies.Methods:The deactivated throat swab samples of coronavirus disease 2019 (COVID-19) patients stored in the laboratory were selected and added on the surfaces of stainless steel, plastic, wood, cardboard and cotton cloth to get simulated pollution samples. The samples were placed at room temperature and 4℃. Three samples of each material were taken in batches and soaked on the 0 d, 1 d, 3 d, 7 d, 14 d and 30 d for nucleic acid extraction. Real-time RT-PCR was used to detect SARS-CoV-2 viral RNA. The recovery rates, detectable time and changes in Ct values of viral RNA on the surfaces of different materials after contamination were recorded and analyzed.Results:After contamination, the recovery rates were 1.75%-2.90% in cotton cloth, plastic and stainless steel, while those were much lower in wood and paperboard. On 30 d after contamination, all material surfaces were positive in SARS-CoV-2 RNA testing. The Ct values of viral RNA on the surface of stainless steel, wood, paperboard and cotton cloth increased rapidly in the first 7 days, and then changed slightly. The Ct values of viral RNA on the surface of plastic changed less comparing to the rest four materials.Conclusions:After the virus contamination on the surface of materials, the viral nucleic acid maintained detective for 30 days with different degradation patterns. In routine environment surveillance, nucleic acid detection and other investigation methods should be integrated to comprehensively evaluation and determine the risk of virus transmission by contaminated goods.

BACKGROUND:No prior study has examined the effects of air pollution on the progression from healthy to chronic lung disease, subsequent chronic lung multimorbidity and further to death.METHODS:We used data from the UK Biobank of 265 506 adults free of chronic lung disease at recruitment. Chronic lung multimorbidity was defined as the coexistence of at least two chronic lung diseases, including asthma, chronic obstructive pulmonary disease and lung cancer. The concentrations of air pollutants were estimated using land-use regression models. Multistate models were applied to assess the effect of air pollution on the progression of chronic lung multimorbidity.RESULTS:During a median follow-up of 11.9 years, 13 863 participants developed at least one chronic lung disease, 1055 developed chronic lung multimorbidity and 12 772 died. We observed differential associations of air pollution with different trajectories of chronic lung multimorbidity. Fine particulate matter showed the strongest association with all five transitions, with HRs (95% CI) per 5 µg/m3 increase of 1.31 (1.22 to 1.42) and 1.27 (1.01 to 1.57) for transitions from healthy to incident chronic lung disease and from incident chronic lung disease to chronic lung multimorbidity, and 1.32 (1.21 to 1.45), 1.24 (1.01 to 1.53) and 1.91 (1.14 to 3.20) for mortality risk from healthy, incident chronic lung disease and chronic lung multimorbidity, respectively.CONCLUSION:Our study provides the first evidence that ambient air pollution could affect the progression from free of chronic lung disease to incident chronic lung disease, chronic lung multimorbidity and death.

目的 探索北京市猩红热发病的时空分布、演变特征及热点区域,为制定精准防控措施提供依据.方法 采用SaTScan软件进行时间扫描和时空扫描分析.利用R软件spdep包进行全局空间自相关分析以判断有无聚集,采用局部Getis-Ord(Gi*)进行热点分析,定位发病的局部聚集区域.结果 2015-2020年北京市猩红热发病率由西南到东北呈逐渐降低趋势.全局空间自相关分析显示,2015-2020年猩红热发病率存在空间聚集现象(Moran's I=0.406,P＜0.001),且为高-高聚集[Ci*=0.005,E(Gi*)=0.003].热点分析结果显示,10个区的48个乡、镇、街道为热点区域,主要分布于南部及西南部郊区,涉及区主要为大兴(12个)、房山(7个)和门头沟区(6个).时空分析显示,2017年4月-2019年1月北京市东南方向存在一个聚集区,2017年4月-2019年12月北京西南方向存在一个聚集区域.结论 2017-2019年北京市猩红热发病略有增加.丰台、房山、门头沟和大兴区等各区交界地应为北京市猩红热防控的重点地区,应在该区域重点人群中加强环境治理,并开展针对呼吸道传染病的预防措施及宣传教育.

Objective:To analyze the genomic characteristics and variations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) derived from an outbreak in inbound flight in Aug, 2022 in Beijing, and provide reference data for disease prevention and control and risk assessment.Methods:Fifty respiratory tract specimens from all cases in this outbreak were collected. The digital PCR (ddPCR) was used to determine the viral loads of the specimens. The full genome of the viruses were sequenced by Next-generation sequencing. Then analuses were performed on the genetic identity, variations and phylogenesis.Results:The median of viral loads in all 50 samples were 5.57×10 4 copies/ml and 5.85×10 4 copies/ml, for ORF1ab gene and N gene, respectively. A total of 46 SARS-CoV-2 genomes were obtained, which all belonged to Omicron/BA.5. Two genome clusters were observed, involving 21 and 7 cases, with a nucleotide sequence identities of 99.993% and 99.997%, respectively. Conclusions:The studied outbreak was composed of two main clusters and other individual cases with Omicron/BA.5 virus overseas.