Only A Few Human Viruses Are Pathogenic o Many viruses on the earth do not infect humans Infections with most of human viruses take place and proceed unnoticed, producing no diseases Non-pathogenic Controlled by human antiviral defensesOnly A Few Human Viruses Are Pathogenic z Many viruses Many viruses on the earth do on the earth do not infect not infect humans z Infections with most of human viruses take place and proceed unnoticed, p g roducin g no diseases ¾ Non-pathogenic ¾ Controlled by human antiviral defenses Controlled by human antiviral defenses