Interferon-inducing polycarboxylates: mechanism of protection against vaccinia virus infection in mice.

The present study was undertaken to examine possible correlations between long-term protection of mice treated with polycarboxylates and infected with vaccinia virus, and the presence of subdetectable amounts of interferon in the tissues, as determined by tissue or organ resistance to replication of viruses. After a single dose of polycarboxylate, splenic resistance to virus replication could be detected. It persisted for 7 to 14 days, but no attempt was made to prove that it was due to subdetectable amounts of interferon. Whole-animal protection lasted longer than splenic resistance. Moreover, when different polycarboxylates and different virus strains were used, patterns of early protection were not correlated with those of splenic resistance. These data, as others presented earlier, suggest that, in addition to interferon, other antiviral mechanisms are stimulated by polycarboxylates.