Comparative efficacy of live replicating sheeppox vaccine strains in Ovines

• Published in: Biologicals Vol. 39; no. 6; pp. 417 - 423
• Main Authors: Yogisharadhya, R., Bhanuprakash, V., Hosamani, M., Venkatesan, G., Balamurugan, V., Bora, D.P., Bhanot, V., Prabhu, M., Singh, R.K.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2011
• Subjects: adverse effects; Animals; antibodies; Antibodies, Viral - blood; Antibodies, Viral - immunology; Capripoxvirus - classification; Capripoxvirus - immunology; Cercopithecus aethiops; Dose-Response Relationship, Drug; Efficacy; Potency; Poxviridae Infections - immunology; Poxviridae Infections - prevention & control; Protective Dose; Real-time PCR; Safety; Sheep; Sheep Diseases - immunology; Sheep Diseases - prevention & control; Sheep Diseases - virology; Sheeppox vaccines; Species Specificity; testes; Time Factors; Treatment Outcome; vaccination; Vaccination - methods; vaccines; Vaccines, Attenuated - administration & dosage; Vaccines, Attenuated - immunology; Vero Cells; Viral Vaccines - administration & dosage; Viral Vaccines - immunology; virulence; viruses; India; Sheeppox vaccines; Efficacy; Potency; Protective Dose; Safety; Real-time PCR
• ISSN: 1045-1056; 1095-8320
• DOI: 10.1016/j.biologicals.2011.09.010

In the present study, two sheeppox vaccines made from strains [sheeppox virus-Srinagar (SPPV-Srin) and Ranipet (SPPV-R)] indigenous to India and adapted to Vero cells were compared in terms of their safety, potency, efficacy and antigenic value with the commercial in-use Roumanian Fanar (SPPV-RF) vaccine, a foreign strain adapted in primary lamb testes cells. The safety test indicated that the SPPV (Sri and RF) vaccines were safe while SPPV-R was not completely attenuated and caused excessive adverse reactions at the passage level tested. The immunized animals showed DTH reaction and resisted virulent SPPV challenge, while control animals developed disease. Specific virus could be detected in the controls and animals immunized with lower dilutions of vaccines after challenge but not in any of the sheep immunized with 1 and 100 doses of each vaccine. All vaccines were found potent and the PD 50 was highest for SPPV (Srin and R) followed by RF. The immunized animals were seroconverted following vaccination with sustained antibody responses after challenge. In conclusion, indigenous SPPV-Srin vaccine was found to be as efficacious as SPPV-R and SPPV-RF vaccines. Thus, there is potential benefit in replacing the currently used commercial vaccine SPPV-RF with indigenous SPPV-Srin vaccine for use in India.