目的 了解西双版纳州乙型肝炎（乙肝）疫苗接种情况，评价乙肝预防效果，为制定免疫策略提供依据。方法 采取分层整群抽样法抽取西双版纳州3个县（市）0~34岁健康人群对象，收集其乙肝疫苗接种史，采集静脉血，用ELISA检测血清标志物乙肝表面抗原（hepatitis B surface antigen，HBsAg）和乙肝表面抗体（hepatitis B surface antibody，HBsAb）。阳性率的比较釆用卡方检验。结果 2016—2020年西双版纳州报告乙肝病例1 647例，年平均发病率35.48/10万。乙肝疫苗估算首针接种及时率为47.98%，全程接种率为55.26%。3 956名调查对象中，HBsAg和HBsAb阳性率分别为2.10%（95%置信区间：1.65%~2.54%）和65.72%（95%置信区间：65.24%~67.20%）。HBsAb阳性率男性高于女性，城区人群高于乡镇，且差异均有统计学意义（χ²分别为18.35、4.48，P值均<0.05）。3个县（市）HBsAg阳性率差异有统计学意义（χ²=11.51，P<0.01）。结论 西双版纳州农村人群乙肝免疫基础较为薄弱。薄弱地区应加强乙肝疫苗免疫接种工作，提高乙肝疫苗的接种率，做好乙肝疫苗免疫强化，完善慢性HBV感染者筛检、诊断、抗病毒治疗等综合防控措施。

Objective  To investigate the vaccination rate and evaluate the immunoprophylaxis effect of hepatitis B vaccine (HepB) in Xishuangbanna Prefecture, in order to set up an evidence-based strategy for prevention and control of hepatitis B. Methods  Stratified cluster sampling was used to select healthy people aged 0-34 years from 3 counties (city) in Xishuangbanna Prefecture. Their HepB vaccination history was collected and venous blood was sampled. ELISA was used for qualitative analysis of serum markers hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb). Chi-square test was used to compare positivity rates. Results  From 2016 to 2020, there were a total of 1 647 cases of hepatitis B in Xishuangbanna, with an average annual incidence of 35.48/100 000. The rate of timely HepB primary immunization was 47.98% and that of complete immunization was 55.26%. In the 3 956 subjects surveyed, the positivity rates of HBsAg and HBsAb were 2.10% [95% confidence interval (CI): 1.65%-2.54%] and 65.72% (95% CI: 65.24%-67.20%), respectively. The positivity rate of HBsAb in male population was statistically significantly higher than that in female population, and higher in city population than in rural population (χ²=18.35 and 4.48, respectively, both P<0.05). The positivity rates of HBsAg were statistically significantly different among 3 counties (city) (χ²=11.51, P<0.01). Conclusions  The HepB immunity in Xishuangbanna Prefecture is weaker among rural population. The weak regions should strengthen HepB immunization to improve the vaccination coverage, strengthen boost immunization, and improve comprehensive prevention and control measures such as screening, diagnosis and antiviral treatment for chronic HBV infected persons.