ANTIINFLUENZA VIRUS ACTIVITY OF VIRAZOLE BY MEANS OF QUANTITATIVE HEMADSORPTION TECHNIQUE

Abstract

Studies were carried out to demonstrate some difference in antiinfluenza virus activity between Virazole (Vz) and adamantadine hydrochloride (Ad) by means of the quantitative hemadsorption (QHA) technique. The results obtained are summarized as follows.
(1) Vz completely suppressed the growth of the B/Lee strain of influenza virus. It reduced the growth of five strains of the type A viruses by 45-80% at a concentration of 33μg/ml. On the other hand, Ad markedly inhibited the growth of the A/AA 2/60 (H₂N₂), A/Japan 305/57 (H₂N₂), and A/Hong kong (H₃N₂) strains, but had little inhibitory effect on the multiplication of any other strain of the influenza viruses.
(2) When the drugs were added to viral cultures as late as 60 minutes after infection with the A/AA/2/60 (H₂N₂) strain, Vz reduced the hemadsorption activity of infected cells by 77%, while 10μg/ml of Ad exerted no significant inhibition upon viral growth. Neither drug, however, affected the adsorption of the influenza A strain onto chick embryo cells.