Poultry vaccination against N.C.D. by means of an intramuscular injection with LaSota strain vaccine; a practical investigation
Voeten, A.C.; Van Laarhoven, P.Y.
Tijdschrift Voor Diergeneeskunde 100(16): 888-893
1975
ISSN/ISBN: 0040-7453 PMID: 1179399 Document Number: 83438
An intramuscular N.D.C. vaccination with LaSota vaccine, in animals of less than ten weeks which were previously vaccinated by the spray method at about 5 days and 25 days against N.C.D., leads to an immunity of at least three months, as expressed by a high concentration of haemagglutination inhibiting antibodies in the circulatory system. If the vaccinated animals are older than twenty weeks, the resulting immunity is very high indeed and shows practically no impairment within a year after vaccination (longer periods have not been investigated), so that it may be assumed that revaccination will not be necessary during the laying period. Antibody variations between different animals of a flock are slight. The residual immunity of previous vaccinations did not appear to affect the development or maintenance of the antibodies. No spread of vaccine was observed. Here it should be noted that animals with a low residual immunity were used for control. It would be desirable to use specifically pathogenfree animals for this purpose, but this is not really practicable in field conditions. Half a hen dose of the LaSota vaccine, dissolved in 1/2 ml physiological saline, was injected into the pectoralis muscle with the help of the Cornwall Pipetting Unit. Twenty flocks, involving 6900 animals, were vaccinated in field conditions. Not a single vaccination gave rise to any vaccination reaction. The method does have a high labour content; which is an objection.