How to Use "virulence" with Example Sentences

1. Have studies of the virus offered any clues to virulence ?
2. There are two crucial factors : the transmissibility of the virus , and its virulence .
3. At the top of the list was the increased virulence of anti-japanese sentiment in modern china .
4. Though the h1n1 strain of the flu hasn 't increased in virulence , experts stress that h1n1 and influenza viruses in general remain unpredictable .
5. Kawaoka 's team observed this virulence in mice and macaques as well , but pigs showed no outward signs of disease even though the virus reproduced capably in the swine respiratory system .