Background: Between mid‐January and early February, provinces of mainland China outside the epicentre in Hubei province were on high alert for importations and transmission of COVID‐19. Many properties of COVID‐19 infection and transmission were still not yet established.Methods: We collated and analysed data on 449 of the earliest COVID‐19 cases detected outside Hubei province to make inferences about transmission dynamics and severity of infection. We analysed 64 clusters to make inferences on serial interval and potential role of pre‐symptomatic transmission.Results: We estimated an epidemic doubling time of 5.3 days (95% confidence interval (CI): 4.3, 6.7) and a median incubation period of 4.6 days (95% CI: 4.0, 5.2). We estimated a serial interval distribution with mean 5.7 days (95% CI: 4.7, 6.8) and standard deviation 3.5 days, and effective reproductive number was 1.98 (95% CI: 1.68, 2.35). We estimated that 32/80 (40%) of transmission events were likely to have occurred prior to symptoms onset in primary cases. Secondary cases in clusters had less severe illness on average than cluster primary cases.Conclusions: The majority of transmissions are occurring around illness onset in an infected person, and pre‐symptomatic transmission does play a role. Detection of milder infections among the secondary cases may be more reflective of true disease severity.

Influenza endangers human health but can be prevented in part by vaccination. Assessing influenza vaccine effectiveness (VE) provides scientific evidence for developing influenza vaccination policy. We conducted a systematic review and meta-analysis of studies that evaluated influenza VE in mainland China. We searched six relevant databases as of 30 August 2019 to identify studies and used Review Manager 5.3 software to analyze the included studies. The Newcastle–Ottawa scale was used to assess the risk of publication bias. We identified 1408 publications, and after removing duplicates and screening full texts, we included 21 studies in the analyses. Studies were conducted in Beijing, Guangzhou, Suzhou, and Zhejiang province from the 2010/11 influenza season through the 2017/18 influenza season. Overall influenza VE for laboratory confirmed influenza was 36% (95% CI: 25–46%). In the subgroup analysis, VE was 45% (95% CI: 18–64%) for children 6–35 months who received one dose of influenza vaccine, and 57% (95% CI: 50–64%) who received two doses. VE was 47% (95% CI: 39–54%) for children 6 months to 8 years, and 18% (95% CI: 0–33%) for adults ≥60 years. For inpatients, VE was 21% (95% CI: −11–44%). We conclude that influenza vaccines that were used in mainland China had a moderate effectiveness, with VE being higher among children than the elderly. Influenza VE should be continuously monitored in mainland China to provide evidence for policy making and improving uptake of the influenza vaccine.

Background: Influenza is a major health threat to the elderly in China. Despite this, influenza vaccination rates still remain low and vary across regions that have different funding policies. In this study, we compare the vaccination status and influencing factors among older adults under the free, partial reimbursement, and self-paid vaccination strategies. Methods: Three cities with free, partial reimbursement, and self-paid influenza vaccination policies were selected. A cross-sectional, anonymous survey was then conducted. A total of 2265 elderly individuals aged 60 years and above were recruited using probability proportionate to size sampling. A standardized questionnaire was used during face-to-face interviews to collect data regarding the influenza vaccination status and influencing factors. The statistical analyses included chi-square tests, a multivariate logistic regression, and random forest models. Results: Among the 2265 participants (free policy region: n = 426; partial reimbursement region: n = 633; self-paid region: n = 1206), vaccination rates during the 2023–2024 season were significantly higher in the free policy region (53.29%) than in the partial reimbursement (20.85%) and self-paid (13.60%) regions (p < 0.001). The intention to vaccinate for the 2024–2025 season was also highest in the free policy region (68.78%), followed by partial reimbursement (47.71%) and self-paid (37.15%) regions (p < 0.001). This result demonstrated the same trend as the vaccination behavior. Cues to action (e.g., healthcare worker or family member recommendations) positively influenced vaccinations across all of the regions. In the self-paid region, perceived barriers, such as vaccine cost and side effect concerns, significantly reduced both behaviors and the next-season intention to vaccinate. Healthcare worker recommendations were key positive factors, while misconceptions and costs were major barriers to vaccination. Conclusions: Vaccination rates varied significantly across regions with different influenza vaccine subsidy policies. The free policy region demonstrated the highest coverage rate, while the self-paid region exhibited the lowest, suggesting that financial policies are a key determinant of vaccination uptake. Furthermore, free vaccination policies were associated with improved influenza vaccine knowledge among the elderly. Analysis of other influencing factors revealed that healthcare workers’ recommendations played a crucial role across all policy regions, though their impact on current-season vaccination behavior and next-season vaccination intention differed by subsidy context. Further studies are needed to explore the best approaches for optimizing region-specific subsidy strategies for promoting influenza vaccination among the elderly in China.

Background: Influenza is a globally prevalent infectious disease caused by influenza viruses, affecting individuals across all age groups. Influenza vaccination is the most effective method for preventing influenza. Vaccine Effectiveness (VE) is used to assess the real-world effectiveness of vaccines. Currently, there is no data on the effectiveness of influenza vaccination in Wuhan. This study employed a test-negative case-control design to evaluate the VE of influenza vaccination in Wuhan during the 2024-2025 season. Methods: A test-negative case-control design was used. Patients presenting with influenza-like illness (ILI) who underwent influenza virus RT-PCR testing at outpatient or emergency departments of 41 medical institutions in Wuhan were selected and classified into case (influenza virus RT-PCR positive) and control (influenza virus RT-PCR negative) groups. Results: This study included 23,302 influenza virus RT-PCR positive cases and 99,424 negative controls. The overall adjusted VE was 35% (95% CI: 30%-40%). Among age groups, the adjusted VE was highest in adults aged 19-59 years and 60-69 years, at 63% (95% CI: 50%-73%) and 60.7% (95% CI: 46%-72%), respectively. The VE was relatively lower in children and adolescents aged 0.5-5 years and 6-18 years, at 25% (95% CI: 17%-33%) and 25% (95% CI: 14%-36%), respectively. Regarding vaccination strategy, the VE for vaccination in both consecutive seasons and vaccination in the current season only were similar, at 42% (95% CI: 28%-54%) and 40% (95% CI: 36%-45%), respectively, while VE for vaccination in the previous season only was 20% (95% CI: 14%-26%). Among vaccination months, protection was highest for vaccination in November, with a VE of 46.1% (95% CI: 36.4%-54.6%). Conclusions:Vaccination in both consecutive seasons and vaccination in the current season only provided better protective effectiveness compared to vaccination in the previous season only (42% vs. 20%). The protective effectiveness of influenza vaccination in November was superior to other months.

Background: Vaccine Effectiveness (VE) provides an important indicator of vaccine performance under real-world conditions. However, evidence regarding influenza VE in Wuhan remains limited. This study applied a test-negative case–control design to estimate the effectiveness of influenza vaccination during the 2024–2025 influenza season in Wuhan. Methods: A test-negative case–control design was conducted among patients presenting with influenza-like illness (ILI) at outpatient and emergency departments of 41 healthcare institutions in Wuhan. All participants underwent influenza virus real-time reverse transcription polymerase chain reaction (RT-PCR) testing and were categorized as cases (RT-PCR positive) or controls (RT-PCR negative) based on laboratory results. Results: The analysis included 23,302 RT-PCR-confirmed influenza cases and 99,424 test-negative controls. The overall adjusted VE was 35% (95% CI: 30–40%). VE differed across age group, with higher estimates observed among adults aged 19–59 years (63%; 95% CI: 50–73%) and 60–69 years (60.7%; 95% CI: 46–72%), whereas lower effectiveness was observed among children aged 0.5–5 years (25%; 95% CI: 17–33%) and 6–18 years (25%; 95% CI: 14–36%). Similar protection was observed among individuals vaccinated in both the 2023–2024 and 2024–2025 seasons (42%; 95% CI: 28–54%) and those vaccinated in the 2024–2025 season only (40%; 95% CI: 36–45%), whereas VE was lower among individuals vaccinated only during the previous season (20%; 95% CI: 14–26%). VE also varied by vaccination timing, with the highest effectiveness observed among individuals vaccinated in November 2024 (46.1%; 95% CI: 36.4–54.6%). Conclusions: Influenza vaccination provided measurable protection during the 2024–2025 season in Wuhan. Greater protection was observed among individuals vaccinated in consecutive seasons or during the current season compared with those vaccinated only in the prior season. Vaccination administered in November was associated with the highest effectiveness, highlighting the importance of appropriate vaccination timing.

Whether task execution results of the smart meter are successful is Boolean and task execution has time sequence. By regarding the data of task execution ability of the smart meter as time series and Boolean, a time-domain extended principal component analysis is proposed to evaluate the smart meter task execution ability in this paper. Firstly, the results of smart meter task execution are extended in the time domain to form the original phasor data matrix by converting Boolean quantity to amplitude and time-series information to phasor phase information. Then, principal component analysis is used to process the original phasor data matrix to determine the key indexes affecting the task execution ability of the smart meter and to establish an index system. Finally, analyzation of historical data of remote payment control of the smart meter in Jibei shows that the key indexes proposed in this paper are reasonable and accurate and the tasks of the smart meter can be guaranteed to be executed efficiently and reliably.