fonz i did some research on your post and must respectfully disagree on several points.
the influenza is certainly a virus on its own. there are even types a,b,and c. classic flu sypmtoms are brough on by a and b. c is more coldlike and milder,
rhinoviruses and coronaviruses cause common colds. there are almost 200 viruses, all broadly similar in their effects. (SARS may be caused by a coronavirus).
the spanish influenza pandemic in 1918.was cause by the type A virus. type A is highly unstabel and new strains constantly arise.
i am confused on your statement about penicillin. how could people infected with the flu be treated with penicillin if was not available yet? penicillin is useless against the flu virus.