Abstract

The prophylaxis of many avian diseases is based on measures of biosecurity and active immunization using live vaccines. One of the most important tests for vaccine quality control is a serum conversion. Serum conversion is performed to check the production of certain virus, after immunization. The Avian Health Unit at LFDA-SP carries out the quality control of commercially available avian vaccines in Brazil. The aim of the study was to evaluate the results of serum conversion of live monovalent vaccines and complex Infectious Bursal Disease vaccines (IBDV) in the period of 2013 to April/2014. Twelve batches of live monovalent vaccines belonging to seven laboratories were tested and 16 batches of immune complex vaccines belonging to two laboratories. The serum conversion test was performed using two vaccine bottles. The vaccines were reconstituted in phosphate buffered saline (PBS), inoculated in SPF chicks according to the manufacturer’s recommendations and kept in BSL-3 isolators. About 21-28 days after the immunization of the chicks were bled via cardiac puncture, the sera were prepared, and analyzed by serological test (ELISA). Monovalent IBD vaccines had geometric mean titers (GMT) ranging from 648 to 10,177, combining the preparation with strong strain with a greater GMT value=10.177. The distant GMT immune complex vaccines ranging from 4,456 to 8,996. The results obtained with the monovalent and immune complex IBD vaccines, showing that all tested batches presented value required by Brazilian law and are therefore approved.

Keywords:Infectious Bursal Disease; Live vaccines; Quality Control; Serum conversion; Official Quality control