The response of ponies to Myxovirus influenzae A-equi 2. I. Serum and nasal antibody titres following exposure.

The antibody response in serum and nasal secretions of groups of ponies vaccinated or infected with Myxovirus influenzae A-equi 2 was examined. Following infection by aerosol with live virus, a weak antibody response was recorded in both serum and secretions. Antibody levels were undetectable in secretions at 31 days after infection. After primary intramuscular vaccination with killed virus, using sodium alginate as an adjuvant, antibody was detected only in the serum. However, following revaccination, a pronounced antibody response was demonstrated in both serum and secretions. Antibody was still detectable in all four ponies when tested 135 days later. Only a serum antibody response was detected in ponies after primary intramuscular vaccination with a commercial vaccine. Upon revaccination nasal antibody occurred in all ponies but this only persisted for about 30 days. Neither serum nor nasal antibody response occurred following intranasal vaccination and revaccination with a killed virus vaccine.