[The simple method of direct estimation of infectious process in mice and rats aerogenically infected with influenza virus].

Multiplication of influenza virus in laboratory animals (mice and rats) after aerogenic inoculation was recorded directly (by the agent accumulation in the lungs and trachea) and indirectly (by interferon concentration in the lungs of mice). Thermal inactivation of influenza virus in chick embryo allantoic fluid was observed (by 4.5-6 Ig within 48 h at 37 degrees C).