"Influenza virus" 是英文中流感病毒的说法。
流感病毒是一种感染人类和动物的病毒，主要通过呼吸道传播。它的来源是鸟类和猪类，但有时也会在其他动物中发现。流感病毒会不断变异，导致人们对它的免疫力减弱，因此每年都会爆发流感流行。
例句:
"The flu virus is highly contagious and can spread easily through coughing and sneezing." (流感病毒非常容易传播，通过咳嗽和打喷嚏可以轻易地传播。)
"The strain of influenza virus that is currently circulating is particularly dangerous for older adults and young children." (目前传播的流感病毒株特别危险，对老年人和儿童尤其危险。)
"Getting a flu shot every year is the best way to protect yourself from the influenza virus." (每年接种流感疫苗是保护自己免受流感病毒感染最好的方法。)