ON-STATION AND FIELD EVALUATION OF INACTIVATED FOWL CHOLERA VACCINE PRODUCED FROM LOCAL Pasteurella multocida ISOLATES, ETHIOPIA
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Date
2018-06
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Abstract
Vaccination is one of the common preventive measures of fowl cholera. An experimental
study on-station and field evaluation was carried out from November 2017 to April 2018.
The objectives of this study were to evaluate the safety, immunogenicity and protective
efficacy of inactivated fowl cholera vaccine recently developed at National Veterinary
Institute of Ethiopia using local Pasteurella multocida isolate. The vaccine was produced
with titer of 2.5x108 cfu/ml and evaluated in 8 weeks old chickens (n=60) by injecting 1
ml through IM (Group I; n=20), 0.5 ml IM route (Group II; n=20) and 20 chickens kept
as unvaccinated control. The sera were collected from all groups’ at day 0, 14, 21, 28,
and 35 and subjected for antibody titer determination by indirect haemagglutination test.
Boostered with the same dose and route after 21 days of primary vaccination. Finally, the
vaccinated and control chickens were challenged using virulent strains of Pasteurella
multocida at day 15 of post booster vaccination. The study at field level was conducted
using 200 chickens isolated in a separate compartment. The chickens were vaccinated
with 0.5ml through IM route at day 0 and booster dose was given with 0.5ml after 21 day
of primary vaccination. Sera were collected at day 0, 21 and 35 and examined by indirect
haemagglutination test. Mean antibody titers of Group I were 1.6±1.2, 211.3±2.1,
244.5±1.2, 319.8±1.2 and 502±1.2 at day 0, 14, 21, 28 and 35, respectively. In Group II,
mean antibody titers were 1.3±1.2, 203.7±3.0, 234.2±1.2, 367.2±1.2.5 and 452.9±1.2 at
day 0, 14, 21, 28 and 35, respectively. In Group III, mean antibody titer remain constant.
In case of protective efficacy, both 1 and 0.5ml dose had 87.5% protection. At field
study, the mean antibody titers were 4.2±1.1, 310.4±1.0 and 532.6±1.0 at day 0, 21 and
35, respectively. Formalin killed fowl cholera vaccine induces immune response and
mean antibody titer increases after booster vaccination in both control and farm
condition. The protective efficacy and immunogenicity between 1 and 0.5 ml dose of the
vaccine was found insignificant difference. Therefore, the use of 0.5ml dose with booster
vaccination at day 21 after primary vaccination is recommended.
Description
A Thesis submitted to the college of Veterinary Medicine and Agriculture of Addis
Ababa University in partial fulfillment of the requirements of the degree of Masters of
Veterinary
Pasteurella multocida
ISOLATES, ETHIOPIA
hesis eterinary Science in Veterinary Microbiology
Keywords
Chickens, immunogenicity, inactivated fowl cholera vaccine, Pasteurella multocid