Osteonecrosis of the femoral head(ONFH)is a disabling orthopedic disease,pathologically characterized by progressive collapse of the femoral head accompanied by destruction of the trabecular and articular cartilage structures,leading to hip joint pain and progressive functional impairment.Bone marrow mesenchymal stem cell-derived extracellular vesicles(BMSC-EVs)show great promise in tissue repair and regeneration,with low immunogenicity and tumorigenicity,and play roles in osteogenesis,angiogenesis,and immunomodulation.This review summarizes the therapeutic effects and underlying mechanisms of BMSC-EVs in ONFH,providing a theoretical basis for its treatment.

Objective:To analyze the epidemic trend and spatiotemporal distribution characteristics of pertussis in Shandong Province from 2015 to 2024.Methods:Data on pertussis cases in Shandong Province from 2015 to 2024 were collected from the China Information System for Disease Control and Prevention. The ArcGIS spatiotemporal method was used to analyze the epidemic trend and spatiotemporal distribution characteristics of pertussis, and determine the hotspots of incidence.Results:From 2015 to 2024, 46 172 cases of pertussis were reported in Shandong Province, with an average annual incidence rate of about 4.60/100 000. The reported incidence rate showed an overall upward trend, and in 2024, the reported incidence rate reached the highest level in history (19.20/100 000) since the implementation of children′s planning immunization. The areas with high incidence rates were mainly located in the central and western regions of Shandong Province, including Jinan city, Liaocheng city, Tai′an city, Zibo city, Binzhou city, Jining city, Dezhou city, Zaozhuang city, and Dongying city. The global spatial autocorrelation analysis showed that the Moran′s I index of incidence rate of pertussis in Shandong Province in each year from 2015 to 2024 was >0.00, showing obvious spatial clustering. Local spatial autocorrelation analysis showed that the "high high" clustering areas were mainly distributed in some counties (cities, districts) in the central and western regions of Shandong Province, which were hotspots for pertussis incidence in Shandong Province. The spatial trend surface analysis showed that the annual incidence rate of pertussis in each year basically decreased from west to east. In the early stage of the north-south direction, there was a curved trend of low north-south and high in the middle. In the middle and later stages, the northern part was mostly in a higher position, indicating that the central and western regions were the high-risk areas for pertussis in Shandong Province. Conclusions:The pertussis epidemic in Shandong Province from 2015 to 2024 has obvious spatiotemporal clustering, and the central and western regions are the key areas for pertussis prevention and control.

Objective:To analyze the epidemiological, etiological characteristics and transmission of an imported D8 genotype measles case in a child in Shandong Province, August 2023.Methods:A study was conducted on a measles case and 16 contacts in Shandong Province in August 2023. Field epidemiological surveys, including recent exposure and immunization history, were conducted. Serum and throat swab samples were collected from all 16 subjects. Measles IgM and IgG antibody levels and avidity were measured by ELISA, while virus detection and genotyping were performed using fluorescence quantitative PCR and RT-PCR. Genetic evolutionary analysis of the obtained sequences was conducted using MEGA and Beast software.Results:The case was an 11-year-old boy, a fifth-grade student, who developed symptoms on August 28, 2023. A total of five close contacts were investigated, including three family members (grandfather, father and sister) and two playmates. Additionally, 11 classmates who had close contact with the case′s sister during the infectious period (within five days after the rash onset) were also investigated. Among the 16 serum samples tested, only one case was positive for IgM, while the other 15 samples were negative for IgM. The results of the serum antibody avidity test showed that among the 16 serum samples, 14 were positive for IgG. Of these, eight had a relative avidity index >55%, indicating high-avidity antibodies; one had a relative avidity index <45%, indicating low-avidity antibodies; and five had an avidity index between 45% and 55%. The IgG detection OD values for the case′s sister and grandfather were higher than those of the other contacts. Based on the vaccination history of the subjects and the results of IgM and IgG tests, it was preliminarily determined that the case had a recent wild-type measles virus infection. The case′s sister and grandfather had a history of measles wild-type virus infection, while the high-avidity antibodies in the other contacts were likely induced by the measles vaccine. The results of the pharyngeal swab tests showed that only the case was positive for measles virus nucleic acid, while the remaining 15 samples were negative for measles virus. The genetic evolutionary analysis revealed that the viral sequence of this case (Mvs/Shandong.CHN/38.23) had a 100% homology with the Hong Kong strain sequence from August 2023. It belonged to a different transmission chain from the D8 genotype strains that appeared in Shandong Province between 2018 and 2019, with sequence homology ranging from 98.0% to 98.8%. The sequence homology within the transmission chain of this case was between 99.1% and 100%. The evolutionary rate of this transmission chain was approximately 8.38×10 -3 sub/site/year, and the most recent common ancestor was estimated to have emerged around the year 2011. Conclusion:This case is the first imported D8 genotype measles case in Shandong Province. There is no spatio-temporal correlation between this case and adult cases of D8 genotype imported from Shandong Province in 2018-2019, indicating a new D8 genotype imported epidemic.

The development of polysaccharide conjugate vaccines, which convert polysaccharide antigens into T-cell-dependent immunogens through covalent conjugation with protein carriers, represents a critical strategy for enhancing immune protection in infants and young children. Globally licensed conjugate vaccines currently employ carrier proteins including Tetanus Toxoid, Diphtheria Toxoid, and Cross-Reacting Material 197. Recent advances have focused on three key areas: novel carrier protein discovery, optimized conjugation strategies, and evaluation of immune interference during co-administration of multivalent formulations. These efforts aim to achieve broader serotype coverage, prolonged protective efficacy, and simplified immunization schedules. This review synthesizes recent progress in carrier protein development, encompassing vaccine design principles, manufacturing processes, safety profiles, and epidemiological effectiveness. Furthermore, it critically examines current selection criteria for carrier proteins, their clinical applications, and persistent challenges, providing strategic insights to inform future conjugate vaccine development and immunization policy optimization in China.

Objective:To analyze the epidemiological, etiological characteristics and transmission of an imported D8 genotype measles case in a child in Shandong Province, August 2023.Methods:A study was conducted on a measles case and 16 contacts in Shandong Province in August 2023. Field epidemiological surveys, including recent exposure and immunization history, were conducted. Serum and throat swab samples were collected from all 16 subjects. Measles IgM and IgG antibody levels and avidity were measured by ELISA, while virus detection and genotyping were performed using fluorescence quantitative PCR and RT-PCR. Genetic evolutionary analysis of the obtained sequences was conducted using MEGA and Beast software.Results:The case was an 11-year-old boy, a fifth-grade student, who developed symptoms on August 28, 2023. A total of five close contacts were investigated, including three family members (grandfather, father and sister) and two playmates. Additionally, 11 classmates who had close contact with the case′s sister during the infectious period (within five days after the rash onset) were also investigated. Among the 16 serum samples tested, only one case was positive for IgM, while the other 15 samples were negative for IgM. The results of the serum antibody avidity test showed that among the 16 serum samples, 14 were positive for IgG. Of these, eight had a relative avidity index >55%, indicating high-avidity antibodies; one had a relative avidity index <45%, indicating low-avidity antibodies; and five had an avidity index between 45% and 55%. The IgG detection OD values for the case′s sister and grandfather were higher than those of the other contacts. Based on the vaccination history of the subjects and the results of IgM and IgG tests, it was preliminarily determined that the case had a recent wild-type measles virus infection. The case′s sister and grandfather had a history of measles wild-type virus infection, while the high-avidity antibodies in the other contacts were likely induced by the measles vaccine. The results of the pharyngeal swab tests showed that only the case was positive for measles virus nucleic acid, while the remaining 15 samples were negative for measles virus. The genetic evolutionary analysis revealed that the viral sequence of this case (Mvs/Shandong.CHN/38.23) had a 100% homology with the Hong Kong strain sequence from August 2023. It belonged to a different transmission chain from the D8 genotype strains that appeared in Shandong Province between 2018 and 2019, with sequence homology ranging from 98.0% to 98.8%. The sequence homology within the transmission chain of this case was between 99.1% and 100%. The evolutionary rate of this transmission chain was approximately 8.38×10 -3 sub/site/year, and the most recent common ancestor was estimated to have emerged around the year 2011. Conclusion:This case is the first imported D8 genotype measles case in Shandong Province. There is no spatio-temporal correlation between this case and adult cases of D8 genotype imported from Shandong Province in 2018-2019, indicating a new D8 genotype imported epidemic.

The development of polysaccharide conjugate vaccines, which convert polysaccharide antigens into T-cell-dependent immunogens through covalent conjugation with protein carriers, represents a critical strategy for enhancing immune protection in infants and young children. Globally licensed conjugate vaccines currently employ carrier proteins including Tetanus Toxoid, Diphtheria Toxoid, and Cross-Reacting Material 197. Recent advances have focused on three key areas: novel carrier protein discovery, optimized conjugation strategies, and evaluation of immune interference during co-administration of multivalent formulations. These efforts aim to achieve broader serotype coverage, prolonged protective efficacy, and simplified immunization schedules. This review synthesizes recent progress in carrier protein development, encompassing vaccine design principles, manufacturing processes, safety profiles, and epidemiological effectiveness. Furthermore, it critically examines current selection criteria for carrier proteins, their clinical applications, and persistent challenges, providing strategic insights to inform future conjugate vaccine development and immunization policy optimization in China.

Osteonecrosis of the femoral head(ONFH)is a disabling orthopedic disease,pathologically characterized by progressive collapse of the femoral head accompanied by destruction of the trabecular and articular cartilage structures,leading to hip joint pain and progressive functional impairment.Bone marrow mesenchymal stem cell-derived extracellular vesicles(BMSC-EVs)show great promise in tissue repair and regeneration,with low immunogenicity and tumorigenicity,and play roles in osteogenesis,angiogenesis,and immunomodulation.This review summarizes the therapeutic effects and underlying mechanisms of BMSC-EVs in ONFH,providing a theoretical basis for its treatment.

Objective:To analyze the epidemic trend and spatiotemporal distribution characteristics of pertussis in Shandong Province from 2015 to 2024.Methods:Data on pertussis cases in Shandong Province from 2015 to 2024 were collected from the China Information System for Disease Control and Prevention. The ArcGIS spatiotemporal method was used to analyze the epidemic trend and spatiotemporal distribution characteristics of pertussis, and determine the hotspots of incidence.Results:From 2015 to 2024, 46 172 cases of pertussis were reported in Shandong Province, with an average annual incidence rate of about 4.60/100 000. The reported incidence rate showed an overall upward trend, and in 2024, the reported incidence rate reached the highest level in history (19.20/100 000) since the implementation of children′s planning immunization. The areas with high incidence rates were mainly located in the central and western regions of Shandong Province, including Jinan city, Liaocheng city, Tai′an city, Zibo city, Binzhou city, Jining city, Dezhou city, Zaozhuang city, and Dongying city. The global spatial autocorrelation analysis showed that the Moran′s I index of incidence rate of pertussis in Shandong Province in each year from 2015 to 2024 was >0.00, showing obvious spatial clustering. Local spatial autocorrelation analysis showed that the "high high" clustering areas were mainly distributed in some counties (cities, districts) in the central and western regions of Shandong Province, which were hotspots for pertussis incidence in Shandong Province. The spatial trend surface analysis showed that the annual incidence rate of pertussis in each year basically decreased from west to east. In the early stage of the north-south direction, there was a curved trend of low north-south and high in the middle. In the middle and later stages, the northern part was mostly in a higher position, indicating that the central and western regions were the high-risk areas for pertussis in Shandong Province. Conclusions:The pertussis epidemic in Shandong Province from 2015 to 2024 has obvious spatiotemporal clustering, and the central and western regions are the key areas for pertussis prevention and control.

In order to understand the knowledge, attitude and practice (KAP) of vaccination against influenza, pneumonia, human papillomavirus (HPV), herpes zoster (HZ), COVID-19, and hepatitis B among staff of vaccination units in Shandong Province, a sample survey was conducted among 797 staffs of adult vaccination units in 12 counties (cities and districts) of Shandong Province from August to September 2022. The results showed that the respondents had the highest total score of knowledge and attitude for the COVID-19 vaccine, with the M ( Q1, Q3) of 23 (20, 25) and 10 (10, 10), respectively, and had the lowest score of knowledge and attitude for the herpes zoster vaccine, with the M ( Q1, Q3) of 19 (15, 22) and 8 (8, 10), respectively. The vaccine-related knowledge point"vaccine applicable population"had the highest score, with the M (Q1, Q3) of 26 (23, 30). The "contraindications/adverse reactions" and "adverse reaction management" had the lowest score, with the M (Q1, Q3) of 24 (20, 29) and 24 (20, 28), respectively. About 89.71% of respondents received one adult vaccine within two years at least. The principal driver for vaccination of 53.58% of recipients was their understanding of vaccines, which was"it was necessary to receive the vaccine". About 66.00% of respondents who had not received any adult vaccine in the past two years had insufficient awareness of the necessity of vaccination and believed that they were in good health and did not need to receive it. In summary, the staff of adult vaccination units in Shandong Province have a poor understanding of the herpes zoster vaccine in terms of vaccines and a relatively poor understanding of"contraindications/adverse reaction and management"in adult vaccination knowledge points.

In order to understand the knowledge, attitude and practice (KAP) of vaccination against influenza, pneumonia, human papillomavirus (HPV), herpes zoster (HZ), COVID-19, and hepatitis B among staff of vaccination units in Shandong Province, a sample survey was conducted among 797 staffs of adult vaccination units in 12 counties (cities and districts) of Shandong Province from August to September 2022. The results showed that the respondents had the highest total score of knowledge and attitude for the COVID-19 vaccine, with the M ( Q1, Q3) of 23 (20, 25) and 10 (10, 10), respectively, and had the lowest score of knowledge and attitude for the herpes zoster vaccine, with the M ( Q1, Q3) of 19 (15, 22) and 8 (8, 10), respectively. The vaccine-related knowledge point"vaccine applicable population"had the highest score, with the M (Q1, Q3) of 26 (23, 30). The "contraindications/adverse reactions" and "adverse reaction management" had the lowest score, with the M (Q1, Q3) of 24 (20, 29) and 24 (20, 28), respectively. About 89.71% of respondents received one adult vaccine within two years at least. The principal driver for vaccination of 53.58% of recipients was their understanding of vaccines, which was"it was necessary to receive the vaccine". About 66.00% of respondents who had not received any adult vaccine in the past two years had insufficient awareness of the necessity of vaccination and believed that they were in good health and did not need to receive it. In summary, the staff of adult vaccination units in Shandong Province have a poor understanding of the herpes zoster vaccine in terms of vaccines and a relatively poor understanding of"contraindications/adverse reaction and management"in adult vaccination knowledge points.