Primary: To determine whether the combination of zidovudine/zalcitabine/interferon alfa-n1 (Retrovir/HIVID/Wellferon) can produce complete responses (i.e., CD4 counts return to >= 800 cells/mm3 for more than 24 weeks) in patients with virus sensitive to all three agents. To determine the antiviral effect of the combination therapies as evidenced by measures of quantitative viral load performed at select study centers only.