What is already known about this topic? Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, the clinical manifestations resulting from different SARS-CoV-2 variants may demonstrate significant variation. What is added by this report? We conducted a comparative analysis of the clinical features associated with SARS-CoV-2 Omicron subvariants BF.7.14 and BA.5.2.48 infections. The results of our study indicate that there are no substantial differences in clinical manifestations, duration of illness, healthcare-seeking behaviors, or treatment between these two subvariants. What are the implications for public health practice? Timely identification of alterations in the clinical spectrum is crucial for researchers and healthcare practitioners in order to enhance their comprehension of clinical manifestations, as well as the progression of SARS-CoV-2. Furthermore, this information is beneficial for policymakers in the process of revising and implementing appropriate countermeasures.

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.

Background: Streptococcus parasuis is a bacterial species recently reclassified from Streptococcus suis . It has been isolated from pigs and cattle, where it may cause various infections. Human infections caused by S. parasuis are rare, with fewer than five publications reported human clinical case to date, and current knowledge regarding its pathogenic potential, antibiotic resistance, and evolutionary context in humans is limited. Results: In this study, the S. parasuis strain S62 was isolated from the blood of a febrile patient. Whole-genome sequencing revealed a genome of 1.93 Mb with a G+C content of 39.5%. Phylogenetic and ANI analyses confirmed that S62 belongs to S. parasuis and is closely related to strains 7500, 221006, NN1, and BS26. The genome harbors virulence-associated genes, including hasC , and putative antibiotic resistance determinants such as a vanY -like glycopeptide resistance gene and the patA–patB efflux system. Phenotypic antimicrobial susceptibility testing showed that S62 was sensitive to most tested antibiotics, with intermediate susceptibility observed only for tetracycline and clindamycin. Functional annotation highlighted the strain’s metabolic versatility and potential for environmental adaptation. Conclusion: This study provides a detailed genomic characterization of a human clinical S. parasuis isolate, shedding light on its virulence potential, resistance determinants, and evolutionary relationships. These findings provide a baseline for further investigation and monitoring of S. parasuis in human infections.

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.

Schools are high-risk settings for influenza transmission. During the 2025-26 Northern Hemisphere season, influenza A(H3N2) subclade K (J.2.4.1) rapidly emerged and became predominant, but vaccine effectiveness (VE) in school-associated outbreaks remains unclear. We conducted a field investigation of 93 school-associated febrile outbreaks in Beijing, China, from September to December 2025. Cases were febrile students with laboratory-confirmed influenza, and afebrile classmates served as controls. VE against laboratory-confirmed symptomatic infection was estimated using mixed-effects logistic regression, adjusting for age, sex, school type, and outbreak-level clustering. A total of 3,797 students were included, of whom 788 were laboratory-confirmed febrile cases and 3,009 were afebrile classmates. Primary schools accounted for 74.2% of outbreaks. Overall vaccination rate was 54.6%, with 50.6% among cases and 56.1% among controls. Unadjusted VE was 19.6% (95% CI: 5.9-31.3). After adjustment, VE against laboratory-confirmed influenza was 30.0% (95% CI: 17.3-40.7). Sensitivity analyses yielded consistent results. Influenza vaccination provided modest protection against symptomatic A(H3N2) infection in school-aged children, even under conditions of high-intensity exposure and antigenic drift. These findings underscore the value of vaccination in outbreak-prone school settings and highlight the importance of ongoing vaccine strain optimization and outbreak-based VE surveillance.