Comparative Evaluation On The Efficacy Of Embryonated Chicken Egg Adapted And Tissue Culture Pigeon Pox Vaccines Against The Local Virulent Strain

Amina A Radwan,Christine Mikhael

doi:10.21608/javs.2020.85605

Abstract

A total of 150 pigeons of 45 days old was used and divided into three groups; the first one was vaccinated with tissue culture adapted pigeon pox vaccine (TCAPPV), and the second was vaccinated with egg adapted pigeon pox vaccine (EAPPV) and the third as a non-vaccinated control group. Birds were observed for ten days post-vaccination (DPV) for the presence of takes. Cellular immunity was detected by lymphocyte proliferation assay on the whole blood for 21 DPV, and serum samples were collected weekly. The level of induced antibodies was detected by the neutralization test for six months post-vaccination. Twenty pigeons of each group were challenged by virulent pp virus at 28th DPV Takes were recognized at the site of vaccination at 4thDPV and increased to the maximum at7th DPV to reach 90% for TCAPPV and 98% for EAPPV. The peak of the cellular immunity by lymphocyte proliferation assay was at the 12thDPV when TCAPPV recorded 1.534 and EAPPV 2.037. Protection was 90% for TCAPPV and 100% for EAPPV. The peak of neutralizing index (NI) at 35thD.P.V for both vaccinated groups; It was 2.75 for TCAPPV and 3.25 for EAPPV. Both vaccines are still potent to the end of examination at the 6thmonth when NI was 1.5 for TCAPPV and 2.0 for EAPPV. This result shows that both eggs adapted PP and tissue culture PP vaccines are efficient in the protection of pigeons in Egypt despite the egg adapted vaccine is more preferable.

Highlights

Embryonated chicken eggs are still and considered as one of the primary substrates for the production of different vaccines
Virulent pigeon pox virus (PPV) A local isolate of PPV virulent Pigeon pox virus was supplied by Reference Strain Bank (RSB), Central Lab for Evaluation of Veterinary Biologic (CLEVB), Abbasia Cairo
Takes were detected at the site of vaccination 4th days postvaccination (DPV) and increased to the maximum at 7th DPV to reach 90% for tissue culture adapted vaccine and 98% for egg adapted vaccine as shown in table (1)

Summary

INTRODUCTION

Embryonated chicken eggs are still and considered as one of the primary substrates for the production of different vaccines They can support the replication of a wide range of viruses. With adaptation to a primate-derived cell substrate, receptor binding sites on the virus are likely to change, resulting in a modified antigen pattern and, a general effect on immunogenicity This genetic adaptation may reverse attenuation for strains that have been developed via passaging in avian cells or create new strains replicating more efficiently in the cell compared to their wild type isolates. Vaccine manufactures are reluctant (averse-opposed) to switch to mammalian cell lines, and a need for immortal avian cell lines has developed (PCT, 2005) This finding does not apply to all viruses relevant to vaccine development, in particular avian viruses. Reported that cell line tissues weren't suitable for the growth of the avipox virus

MATERIALS AND METHODS

Methods

Evaluation of the cell-mediated response

Evaluation of the cell-mediated response a- Assay of lymphocyte blastogenesis

DISCUSSION

CONCLUSION