Antiviral and anti-invasive titers of human interferons.

The titers of preparations of human leukocyte and human fibroblast interferon were examined to determine their antiviral and anti-invasive activity. The examinations showed a very high correlation of these activities in human fibroblast interferon (r = 0.99), whereas the correlation for human leukocyte interferon was lower. These two interferons have also been found to differ in the relation between antiviral and anti-invasive titers. This difference is highly significant (p less than 0.001).