Objective: To evaluate the incremental vaccine effectiveness (VE) of two dose of the mumps containing vaccine (MuCV) in chidren, so as to provide a basis for optimizing mumps immunization strategies. Methods: A 1∶2 frequency matched case-control study was conducted by using reported mumps cases in childcare centers or schools from Lu an, Hefei, Ma anshan and Huainan cities of Anhui Province from September 1, 2023 to June 30, 2024, as a case group(383 cases). And healthy children in the same classroom were selected as a control group(766 cases). The MuCV immunization histories of participants were collected to estimate the incremental VE of the second dose of MuCV against mumps. Group comparisons were performed using the Chi square test or t-test. For matched case-control pairs, the Cox regression model was employed to calculate the odds ratio (OR) with 95% confidence interval (CI) for two dose MuCV vaccination and to estimate the incremental vaccine effectiveness (VE). Results: There were no statistically significant differences between the case and control groups regarding gender, age, dosage of MuCV vaccination and the time interval since the last dose vaccination( χ 2/t=0.05, 0.20, 0.94, -0.02, P >0.05). The proportions of the case and control groups vaccinated with two doses of MuCV were 26.63% and 29.37%, respectively, and the overall incremental VE of the second dose of MuCV was 40.73% (95% CI=3.03%-63.77%, P <0.05). Subgroup analyses revealed that the incremental VE for children with a period of ≥1 year between the two doses of MuCV was 54.13% (95% CI=1.90%-78.56%, P <0.05), while for children with a period of <1 year, it was 30.63% (95% CI=-28.59%-62.58%, P >0.05). The incremental VE of the second dose of MuCV was 30.36% (95% CI=-25.95%-61.50%, P >0.05) in kindergarten children and 66.73% (95% CI=14.92%-86.99%, P <0.05) in elementary and secondary school students. The incremental VE was 28.78% (95% CI=-27.46%-60.21%, P >0.05) within five years of the last dose of MuCV vaccination and 66.07% (95% CI=-41.56%-91.87%, P >0.05) for vaccinations administered beyond five years. Conclusions The second dose of MuCV may offer additional protection for children; however, extending the interval between two dose of MuCV (<1 year) has shown limited incremental protective effects. Therefore, it is crucial to consider optimizing current immunization strategies for mumps.

BACKGROUND:Artificial intelligence-assisted bone age assessment has become a research hotspot.Domestic and foreign studies have shown that the rapid development of artificial intelligence technology in the field of medical imaging provides the possibility of more accurate and rapid assessment of bone age. OBJECTIVE:To investigate the consistency between a domestically developed artificial intelligent Greulich-Pyle(GP)bone age assessment system and an expert manually assessed GP(expert GP),and to provide a basis for the feasibility of applying an artificial intelligent GP in clinical practice or in other fields. METHODS:Wrist radiographs were sampled from children and adolescents aged 6-15 years,of whom 672 were male and 650 were female.Bone age assessment of the same wrist radiograph was performed using the artificial intelligent GP and the expert GP.The accuracy of the artificial intelligent GP reading results was assessed by the absolute value of the difference.The consistency of the bone age results was assessed by Pearson correlation and Bland-Altamn distribution;and the consistency of the assessment was checked by Kappa test. RESULTS AND CONCLUSION:The absolute value of the difference(95%confidence interval)of the difference between artificial intelligent GP and expert GP for male and female was 0.39 years(0.37-0.41 years)and 0.32 years(0.29-0.34 years),respectively.The deviation of Bland-Altamn values for male and female was(-0.096±0.482)years and(0.014±0.415)years,respectively.The correlation results between artificial intelligent GP bone age and expert GP bone age for male and female were r=0.991 and r=0.992,respectively(P<0.000 1).The median difference between all age groups for male and female was within 0.5 years.Kappa test values were greater than 0.4 for both sexes at all ages except for the 9-year age group for male.Overall Kappa values were 0.603 and 0.659 for male and female respectively.To conclude,there is a high degree of consistency between the artificial intelligence and expert evaluation results of GP bone age values in children and adolescents aged 6-15 years.

BACKGROUND: In China, three bone age assessment methods have been widely used in the medical and sports fields, including the Greulich-Pyle atlas method (GP method), CHN scoring method (CHN method), and China 05 method. A large-sample empirical study is required to determine which method is more suitable for assessing bone age of children and adolescents. OBJECTIVE: To provide a scientific evidence for appropriate bone age evaluation standards for children and adolescents in the eastern developed areas, by comparing the GGP method, CHN method and China 05 method based on samples of healthy children from Shanghai. METHODS: A total of 4 152 healthy children and adolescents (2 185 boys and 1 967 girls) from the urban area of Shanghai were selected for the study. Their digital X-ray of the left hand and wrist were collected and evaluated by the GGP method, CHN method and China 05 method. The difference between the bone age and the chronological age was used to assess the applicability of different bone age standards. The study was approved by the Ethics Committee of Shanghai Research Institute of Sports Science, and informed consent was given by all parents of the enrolled students. RESULTS AND CONCLUSION: For the GP method, the difference between bone age and chronological age in both genders at the age of ≥ 8 years was-0.12 to-0.65 year with significant difference, except for 8-year-old girls. The significant age difference at the age of ≥ 9 years was 0.18 to 1.62 year, except for the 9-year-old age group. For the CHN method, the difference between bone age and chronological age among 6-17-year-old boys and 6-16-year-old girls was 0.42 to 1.56 years (P < 0.01). For the China 05 method, the difference between bone age and chronological age was 0.20 to 0.53 in 6-16-year-old boys (P < 0.01), 0.08 in 17-year-old boys (P > 0.05), and-0.60 in 18-year-old boys (P < 0.01); the age difference among 6-17-year-old girls was-0.01 to 0.56 year, and the difference was not significant in most age groups. Among the three methods, the result of China 05 method is relatively better, which is the best method that matches the current development of teenagers in Shanghai, suggesting that the China 05 method is more suitable for the eastern developed areas with economic level similar to Shanghai. All the three methods have some limitations. Considering the long-term growth trend of adolescents, it is necessary to revise the current bone age evaluation standards.