Vaccinia Tian Tan (VTT) was used as a vaccine against smallpox in China for millions of people before 1980, yet the biological characteristics of the virus remain unclear.

• 尽管痘苗病毒天坛株曾作为天花病预防疫苗在中国大范围接种使用了几十年,但其相关的生物学特性并没有详细的研究和报导。