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.

Preliminary report on vaccination in Croatia against poliomyelitis with type 1 (CHAT) and type 3 (W-Fox) attenuated polioviruses of Koprowski.

The incidence of poliomyelitis in the People's Republic of Croatia has progressively increased since 1945, and in 1953 and 1960 there were serious epidemics. In order to protect the age-groups at greatest risk a mass vaccination campaign was carried out with Koprowski live-virus vaccine in the early spring of 1961, covering the entire population aged 3 months to 20 years. Altogether 1 339 244 persons were given type 1 (CHAT strain), and 1 287 909 received type 3 (W-Fox).