He noted that Tamiflu, the most commonly used antiviral, can have serious side effects that the CDC did not cite.

CNN: Feds update H1N1 antivirals guidelines

The therapy includes injections of the drug interferon, which stimulates the immune system and causes the bulk of the difficult side effects, and two antiviral drugs taken orally.

WSJ: Hepatitis C Dilemma: Treat Illness With Interferon Now or Wait?

Interferon helps, despite the nasty side effects, because it works by a general antiviral mechanism that avoids these problems.

FORBES: Why Aren't There AIDS-Style Cocktails for Hepatitis C?

The goal, Gilead said in its press release, is to create an all-oral treatment for hepatitis C that would replace the difficult treatment with injected interferon and ribavirin, an antiviral pill, along with the fatigue and other side effects they cause.

FORBES: Gilead Tries To Revive Itself With $11 Billion Purchase Of Pharmasset

But even with shorter regimens, both drugs will still have to be given with interferon alpha, the two-decade old antiviral drug made by Merck and Roche that causes nasty flu like side-effects, including fever and fatigue.

FORBES: Why Aren't There AIDS-Style Cocktails for Hepatitis C?