There are two basic stages of yaws disease - early (infectious) and late (non-infectious).

雅司病有两个基本阶段：早期(有传染性)和晚期(无传染性)。

youdao

Novavax, another American start-up, has had similarly promising results using “virus-like particles” (made of non-infectious viral proteins purged of genetic material).

美国另一家新型企业—诺瓦瓦克斯公司用类病毒物质（即未感染的病原蛋白，且去掉其遗传物质）得到了差不多的结果，都很有前景。

youdao

If approved by national regulatory authorities, the non-infectious virus could be studied in a broader variety of LABS, removing a major roadblock to finding a cure.

如果能够被国家调控部门批准，这种“无害型”病毒就能在更多的实验室进行研究，为寻找治疗方法扫清最大的障碍。

youdao

Researchers are also working on needle-less vaccines and jabs against non-infectious diseases such as certain cancers.

ECONOMIST: Big drugs companies see a bright future for vaccines

"Non-infectious vaccines would clearly provide a safeguard against this risk", said Dr Andrew Macadam, a virologist specialising in polio at the National Institute for Biological Standards and Control in Hertfordshire.

BBC: Synchrotron yields 'safer' vaccine