Neutralization and Hemagglutination Inhibition of Swine Influenza Virus by Serum from Suckling Swine and by Milk from Their Dams

Abstract

A study was made on milk from three dams and serum from their 28 pigs for the relationship of antibodies capable of neutralizing or causing hemagglutination inhibition of swine influenza virus. Both neutralizing and hemagglutination-inhibiting antibodies were present in the colostrum of the dam in high titer, but the titers dropped considerably during the first four weeks. Thereafter the rate of loss was less rapid. Neither antibody was found in the serum of the newborn pig prior to nursing, but both-were present in the serum in high titer within 30 hours. The loss of titer in the serum after 30 hours was gradual over an 8-week period.