鉴于天花病毒在生物恐怖和生物战中的特殊地位，近十年来，天花疫苗的研究重新得到重视。到目前为止，天花疫苗研究已进入第四代，已有三代天花疫苗可供使用。其中，第一代天花疫苗在全球消灭天花中起到重要和关键的作用，但不良反应较强。第二代疫苗改进了生产工艺，降低了外源因子污染的可能。第三代疫苗有效地降低了疫苗的毒力，增强了安全性，但免疫效力有所下降。第四代疫苗系使用基因工程技术研制的疫苗，效果尚待评价。由于天花已经消灭，在新疫苗的研究中，
如何评价其免疫效果成为妨碍疫苗研究进展的关键环节。

 In the last decade, the research on smallpox vaccine have been paid much more attention because of the special position of variola virus in bioterrorism and biological
warfare. To date there are 4 generations of smallpox vaccines have been developed, and 3 generations of the vaccines can be used. Among them, the first generation smallpox vaccine plays an important role in the the achievement of global smallpox eradication, but its adverse reactions are strong. The second generation smallpox vaccines possess the theoretical advantages conferred by improved manufacturing process and lowered risk of contamination by adventitious agents. The third generation smallpox vaccines have reduced virulence and improved safety, but the immunological efficacy also descended. The fourth generation smallpox vaccines are developed by techniques for genetic engineering, and the efficacy remains to be evaluated. Owing to global smallpox eradication the evaluation of the immunological efficacy of new smallpox vaccines become the key procedure which can hinder the development of new vaccines .