目標：台灣B肝疫苗政策實施近30年，但少有成本效益研究，本文擬從成本角度來評估台灣的B肝疫苗政策。方法：整理比較台灣與其他國家的B肝疫苗政策，除了都有全面疫苗接種外，在抗原篩檢和B肝免疫球蛋白（HBIG）的使用上仍有一些差異：1.中國式策略（CH）－不做產婦抗原篩檢，也沒給嬰兒HBIG；2.美國式策略（USA）－產婦只篩檢HBsAg，給所有HBsAg陽性母親所生嬰孩HBIG；3.台灣一階段篩檢策略（TW1）－產婦同時篩檢HBsAg和HBeAg，給兩者都陽性產婦所生嬰孩HBIG；4.台灣兩階段篩檢（TW2）－產婦先篩檢HBsAg，如果HBsAg陽性再繼續篩檢HBeAg，給兩者都陽性產婦所生嬰孩HBIG。我們比較這四種策略的抗原篩檢、疫苗與HBIG等費用。結果：不管B肝帶原率多少，TW2都是最便宜，而TW1都是最昂貴的策略。隨著B肝帶原率下降，HBIG的使用需求會越來越少。從策略TW1改為TW2所節省下篩檢HBeAg的費用，足夠讓所有B肝帶原母親所生嬰孩一劑免費的HBIG。結論：台灣目前B肝防疫實務是TW1，浪費很多錢在HBeAg篩檢上。建議改為TW2，才是最經濟的策略。此外為了提供嬰兒完善的保護，建議給所有HBsAg陽性帶原母親所生嬰孩一劑免費的HBIG。

Objectives: To study the cost-effectiveness of the hepatitis B virus (HBV) immunization policy in Taiwan after its implementation for nearly 30 years. Methods: Existing HBV immunization policies in different countries were compared. They all have universal HBV vaccination, but differ in maternal antigen screening and the use of hepatitis B immunoglobulin (HBIG). Strategy 1: Chinese strategy (CH)-no maternal screening and no HBIG for neonates; Strategy 2: American strategy (USA)-The parturients are screened for HBsAg, and HBIG is administered to all neonates of HBsAg-positive mothers; Strategy 3: Taiwan 1-step strategy (TW1)-The parturients are simultaneously screened for HBsAg and HBeAg, and HBIG is administered to all neonates of HBeAg-positive mothers; and Strategy 4: Taiwan 2-step strategy (TW2)-The parturients are screened for HBsAg first, then screened for HBeAg if HBsAg is positive, and HBIG is administered to all neonates of HBeAg-positive mothers. Results: Regardless of the HBV carrier rate, the TW2 is always the least expensive HBV vaccination protocol and the TW1 is most expensive. As the HBV carrier rate decreases, the need for HBIG also decreases. The cost-savings realized during the change from TW1 to TW2 is enough for the government to provide one free dose of HBIG for all babies born to HBsAg-positive carrier mothers. Conclusions: The current practice of HBV immunization policy in Taiwan is the TW1, which unnecessarily consumes financial resources for maternal HBeAg testing. We suggest the TW2 replace the TW1. To provide comprehensive protection, we recommend giving free HBIG for all neonates born to HBsAg-positive mothers regardless of the HBeAg status.