Rifampin Inhibition of H-1 Virus Infection in Hamsters

Actions of the rifamycins.

“…The large amounts of rifampin required naturally preclude any clinical application of the drug as an antiviral agent. It may be relevant in this respect that Engle et al (36) found rifampin inactive in the mouse against vaccinia virus, even when administered to mice in maximally tolerated doses, whereas a partial inhibitory action of the drug was demonstrated in H-1 virus infections of hamsters.…”

Antiviral Antibiotics: Inhibition of Focus-Formation in Human or Mouse Cell Cultures by Sarcoma-Inducing Oncornaviruses with Rifamycins

“…Rifampicin does not inhibit the RNA polymerase activity of vaccinia virus particles [29][30][31][32], It appears to exert its antiviral effect in this instance through a block of virion assembly [33,34] and a concomitant block in the cleavage of a polypeptide which is a precursor of a core poly peptide of the virion [35.36]. The antivaccinia effect is restricted to rifampicin and certain rifamycin SV-3 formyl hydrazones [37], Rifampicin was found to show a partial inhibition in treatment of H-l virus infection in hamsters but was inactive in the treatment of vaccinia infection of mice [38,39]. Rifampicin was shown by Vaheri and Hanafusa [40] and by Robinson and Robinson [41] to inhibit production of foci of morphologically altered chick cells by Rous sarcoma virus (RSV) at concentrations >20 gg/ml.…”