[Importance of secretory antibodies in nonsusceptibility to influenza B disease and the prevention of the spread of this virus].

Under the conditions of the natural outbreak of influenza B a rise in the level of antibodies in the blood serum and respiratory tract secretions has been found to occur in nonimmunized persons during this disease. Secretory antibodies, along with serum antibodies and in interaction with them, prevent the development of clinically manifest influenza. The asymptomatic form of influenza infection has been revealed: during this form of the disease the response of the body is limited to the local immunity system.