Susceptibility of different strains of influenza a virus to the inhibitory effects of 2-deoxy-2,3-dehydro-N-trifluoroacetylneuraminic acid (FANA)

Abstract

Susceptibility to the neuraminidase-inhibiting effects of a synthetic analog of neuraminic acid, 2-deoxy-2,3-dehydro-N-trifluoroacetylneuraminic acid (FANA) was found to vary among different strains of influenza A virus according to the neuraminidase they contain. In particular, NWS (H0N1) virus and recombinant strains which derive their neuraminidase from NWS are especially susceptible to FANA as measured by the concentrations of inhibitor which reduce rates of elution from red cells, in vitro neuraminidase activity using fetuin as a substrate, and virus replication in cell culture under agar. Growth in tissue culture of X-7 (H0N2) virus and all recombinant viruses containing N2 neuraminidase is approximately 50–200 times less susceptible to inhibition by FANA.These results provide further evidence that the inhibitory effects of FANA on the replication of influenza viruses are mediated by its specific neuraminidase-inhibitory activity and confirm that neuraminidase activity is necessary for the replication of influenza viruses.