adj.无毒力（害）的；无致病力的

The avirulent strain of the flu virus caused only mild symptoms in most patients.
这个无害的流感病毒株在大多数患者身上只引起轻微症状。
The farmer successfully vaccinated his livestock against the avirulent form of the disease.
农夫成功地为他的牲畜接种了抵抗无害病毒形式的疫苗。
The avirulent bacteria did not spread widely in the community due to effective hygiene measures.
由于有效的卫生措施，无害的细菌没有在社区中广泛传播。
The scientist isolated an avirulent variant of the virus for research purposes.
科学家为了研究目的分离出了一种无害的病毒变种。
The avirulent strain of the virus proved to be less deadly than initially feared.
这种无害的病毒株被证明比最初担心的要少致命。
The patient recovered quickly from the avirulent infection, without needing hospitalization.
患者从这次无害的感染中迅速恢复，无需住院治疗。
The experimental vaccine was found to be 98% effective against the avirulent strain.
实验性疫苗被发现对无害病毒株有98%的有效性。
The farmer decided to cull the herd after discovering an avirulent outbreak among the cows.
农场主在发现牛群中有无害的疫情爆发后，决定进行清群。
The scientists studied the avirulent strain to better understand its transmission mechanisms.
科学家们研究了无害的病毒株，以更好地理解其传播机制。
The doctor prescribed a mild antibiotic for the patient's avirulent bacterial infection, knowing it wouldn't pose a serious threat.
医生为患者的无害细菌感染开了轻剂量抗生素，知道它不会构成严重威胁。