Implementation of the INTA Guinea pig model as the official Immunogenicity Test to evaluate the immunogenicity of BoHV-1 inactivated vaccines present in the Argentinean market

PARREÑO, VIVIANA; BARROS, VIRGINIA; GONZALEZ THOMAS, VALERIA; DANIELA RODRIGUEZ; D'ALOIA, RICARDO; FERNANDEZ, FERNANDO; MARADEI, EDUARDO

Madison

Congreso; 31 American society for Virology Annual Meeting; 2012

American Society for Virology

Implementation of the INTA Guinea pig model as the official test to evaluate the immunogenicity of BoHV-1 inactivated vaccines present in the Argentinean market Viviana Parreno1, Virginia Barrros2, Daniela Rodriguez1, Valeria Gonzalez2, Ricardo D´Aloia2, Laura Marangunich3, Virgina Lopez4, Fernando Fernandez1, Eduardo Maradei2. 1Instituto de Virologia, INTA, Argentina, 2DILAB-SENASA, Argentina, 3UNTREF, Argentina, 4UBA, Argentina Bovine herpesvirus type 1 (BoHV-1), in the cause of the Infectious Bovine Rhinothracheitis (IBR. The infection is worldwide distributed and several European countries had implemented eradication programs. Several combined inactivated vaccine to prevent bovine respiratory and reproductive syndromes including BoHV-1 are available in Argentina. This study evaluates the immunogenicity of these vaccines using a recently validated guinea pig model. The Argentinean Veterinary Health Department (SENASA) audited 11 vaccines companies and a total of 46 aqueous and 18 oiladjuvanted commercial vaccines were evaluated. Two monovalent vaccines containing 3.16x10^7 TCID50 of BoHV-1/dose, formulated in oil and aqueous adjuvant, were used as controls. Groups of 5-6 guinea pigs were immunized with two doses of vaccine, 21 days apart and sampled at 30 days post-vaccination. BoHV-1 antibody (Ab) response was measured by ELISA and virus neutralization (VN). References vaccines were approved with very high Ab titers titers and quality control charts were elaborated. The mean VN and ELISA Ab titers induced by the commercial vaccines were significantly lower to the mean Ab titers induced by the reference vaccines. In fact, 65%(31/46) of the aqueous and 50%(9/18) of the oil vaccines tested were approved but 24 vaccines were rejected. The mean VN and ELISA Ab titers induced by the approved vaccines were statistically similar between oil and aqueous formulations and comparable to their reference counterparts. In addition, there was no statistical difference among the mean Ab titers to BoHV-1 of monovalent vs. multivalent vaccines (2-4 viral antigens). The obtained results indicates that the used of the guinea pig model as the official BoHV-1 vaccine potency test represents a reliable tool that will contribute to guarantee the presence of effective products in the market.