Oil Emulsion Newcastle Disease Vaccine Research Articles

Evaluation of Quality of Two Commercial Oil-Emulsion Newcastle Disease Vaccines In-vivo and In-vitro

Evaluation of Quality of Two Commercial Oil-Emulsion Newcastle Disease Vaccines In-vivo and In-vitro

POTENCY TEST OF COMMERCIALLY AVAILABLE INACTIVATED NEWCASTLE DISEASE VACCINES IN SERBIA

In order to evaluate the efficacy of inactivated oil-emulsion Newcastle disease vaccine (commercially available on market in Serbia) we carried out the potency test in chickens, using hemagglutination inhibition (HI) test for detection of antibodies. Th e values of HI titers in the serum before and three weeks aft er vaccination revealed immunoconversion (IC) in chickens, and indicated potential diff erences in the immunoconversion values between two groups vaccinated with monovalent and polyvalent vaccine. In the period 2010-2012, 27 vaccines were tested, there of 21 polyvalent and six monovalent ones. Th ree weeks aft er the vaccination, HI titers of all vaccines were high. Th e average IC values were calculated as log2 (HI titer). The values ranged from 2.2 to 8.2 for polyvalent vaccine, whereas average values for monovalent vaccines were in the range from 3.2 to 6.3. Three weeks post vaccination; no statistically signifi cant diff erences were recorded in the immune response between the tested groups of birds (vaccinated with monovalent and polyvalent vaccines). This supports the fact that both tested vaccines demonstrated good potency to creating immunity against ND in vaccinated birds.

Serology-based potency test for inactivated Newcastle disease vaccines.

Twenty-seven inactivated oil-emulsion Newcastle disease vaccines were tested for potency in chickens. Serum samples from groups given 1/50 dose of vaccine were examined by the haemagglutination inhibition (HI) test and the indirect enzyme-linked immunosorbent assay (ELISA). Good correlations were observed between potency and HI titres and between potency and ELISA absorbance. It is recommended that a serology-based potency test replaces the challenge test, reserving challenge only for those batches of vaccines where a clear pass is not indicated.

Determination of Hemagglutination Activity Recovered from Oil-Emulsion Newcastle Disease Vaccines as a Prediction of Efficacy

Hemagglutination (HA) activity was recovered from the aqueous phases of commercially and experimentally prepared oil-emulsion (OE) Newcastle disease virus (NDV) vaccines using two methods: aqueous partition and freeze-thaw. Quantitation of the HA activity retrieved by the aqueous partition technique was directly related to the degree of protection conferred to chickens against a strain of velogenic viscerotropic (VV) NDV in nine of the ten vaccines analyzed. One of the ten vaccines yielded high levels of retrieved HA activity but induced low hemagglutination-inhibition (HI) antibody levels and low levels of protection. Therefore, the retrieval and quantitation of HA activity from OE NDV vaccines using the partition technique provides a useful adjunct to vaccine testing methods that doesn't require vaccination and challenge trials. The freeze-thaw method did not yield measurable HA titers for all vaccines with high efficacy, so its use should be restricted to only those vaccines for which it has been demonstrated to be suitable.

Newcastle disease vaccination in Malaysia: application of oil emulsion vaccine.

An experimental oil emulsion Newcastle disease vaccine was evaluated for its efficacy in broiler chickens. A group of chickens vaccinated at one day old with a live lentogenic Newcastle disease vaccine and subsequently revaccinated at three and eight weeks old with the experimental oil emulsion vaccine showed satisfactory haemagglutination inhibition antibody response which persisted for 18 weeks. Between 90 and 100 per cent of the vaccinated chickens were protected when challenged with the velogenic viscerotropic Newcastle disease virus. Although the vaccinated chickens were protected against clinical disease, virus could be isolated from a number of birds. By day 10 to 12 after challenge all the chickens were free from Newcastle disease infection.

Influence of Formulation on the Efficacy of Experimental Oil-Emulsion Newcastle Disease Vaccines

Twenty-one experimental oil-emulsion vaccines with different emulsifier contents, aqueous-to-oil ratios, and antigen concentrations were compared by immunization of 4-week-old chickens. Vaccines that contained oil-phase (Arlacel 80) and aqueous-phase (Tween 80) emulsifiers induced 2-to-4-fold higher hemagglutination-inhibition titers than vaccines with only the oil-phase emulsifier. The emulsion vaccines containing both emulsifiers were also more stable at 37 C and less viscous than those containing only the oil-phase emulsifier. Vaccines that had different aqueous-to-oil ratios and contained different quantities of allantoic-fluid antigen (1.2% to 50% of the vaccine volume) induced similar protection against challenge, but hemagglutination-inhibition titers were proportional to the amount of antigen added. Vaccines that had different aqueous-to-oil ratios but contained equal amounts of antigen induced similar hemagglutination-inhibition titers and similar protection against challenge.

Vaccination of Broiler Chicks from Breeder Flocks Immunized with a Live or Inactivated Oil Emulsion Newcastle Disease Vaccine ,

One-day-old chicks used in this study were from breeder flocks vaccinated with live (B1 and LaSota) or inactivated oil emulsion Newcastle disease (ND) vaccine. Chicks were vaccinated against ND by various procedures. The vaccination response was evaluated by hemagglutination-inhibition antibody titers and by challenge. Chicks from breeder flocks vaccinated with live virus vaccine had a geometric mean hemagglutination-inhibition antibody titer (GMT) for Newcastle of 7 (low maternal antibody titer) at 1 day of age, whereas those chickens derived from breeder flocks vaccinated with inactivated oil emulsion ND vaccine had a GMT of 84 (high maternal antibody titer).One-day-old chicks injected with live B1 vaccine were not immunized against ND regardless of breeder flock source. However, chickens with low maternal antibody titers were effectively immunized against ND when injected at 1 day of age with an inactivated or inactivated plus live ND vaccine. Chicks with high maternal antibody titers were not effectively protected when vaccinated with inactivated vaccine at 1 day of age; however, these chicks were protected when injected with a combined live and inactivated ND vaccine.Chicks from both breeder flocks were effectively immunized against ND when injected at 1 day of age with a live or inactivated ND vaccine and revaccinated by aerosol at 21 days of age with live B1 ND vaccine. Even though they were protected against ND, there appears to have been an interference phenomenon in chicks derived from breeder flocks vaccinated with the live ND vaccine.Beak-O-Vac vaccinated chickens were not effectively protected against ND when compared with chicks vaccinated by aerosol at 1 day of age. Water vaccination at 7, 14, or 21 days of age was as effective as aerosol vaccination when administered to chicks with low maternal antibody titers. However, water vaccination was not as effective as aerosol vaccination when administered to chicks with high maternal antibody titers.

Further Studies with an Inactivated Oil Emulsion Newcastle Disease Vaccine in Broiler Breeders

Chickens vaccinated with a live Newcastle disease (ND) vaccine and subsequently revaccinated with an inactivated oil emulsion ND vaccine had higher and more persistent hemagglutination-inhibition (HI) antibody titers than birds vaccinated with live ND vaccine. The geometric mean HI antibody titers of flocks vaccinated with the inactivated ND vaccine ranged from 121 to 172, whereas the titers of flocks vaccinated every 90 days with a live ND vaccine ranged from 18 to 54.Breeder flocks revaccinated with live LaSota ND vaccine had lower egg production than the flocks vaccinated with inactivated vaccine. The average egg production per hen for the 40-week laying cycle was 174 and 170 eggs per hen for hens in the two houses vaccinated with the inactivated vaccine. Hens vaccinated with the live virus vaccine averaged 167 and 164 eggs per hen. The increase in egg production would more than offset the additional cost of the oil emulsion ND vaccine as well as the cost of injecting each individual bird at 18 weeks of age.Between 8 and 32 weeks after onset of egg production, geometric mean maternal antibody titers in 1-day-old chickens derived from breeders vaccinated with live ND vaccine ranged from 7 to 24, whereas, chicks from breeders vaccinated with the inactivated oil emulsion vaccine had maternal antibody titers that ranged from 64 to 89.

Field Trials with an Oil Emulsion Newcastle Disease Vaccine in Broiler Breeders ,

Chickens vaccinated with live Newcastle disease (ND) vaccine and subsequently revaccinated with an inactivated oil emulsion vaccine had high and persistent hemagglutination-inhibition (HI) antibody titers for at least 40 weeks. The geometric mean HI antibody titers of flocks vaccinated with the inactivated ND vaccine ranged from 48.8 to 91.9, whereas the titers of flocks vaccinated every 90 days with a live ND vaccine ranged from 8.6 to 43.5.Breeder flocks revaccinated with a live LaSota ND vaccine had lower egg production than the flocks vaccinated with the inactivated vaccine. The average egg production per hen for the 40 week laying cycle was 177.8 and 174.8 eggs per hen for hens vaccinated with the inactivated vaccine, whereas those hens vaccinated with the live virus vaccine averaged 163.0 and 155.6 eggs per hen. The increase in egg production would more than offset the additional cost of the oil emulsion NDV vaccine as well as the cost of injecting each individual bird at point of lay.Maternal antibody titers in one-day-old chicks were related to the titers in the dams. Maternal antibody titers in chicks originating from breeder flocks vaccinated with the oil emulsion vaccine were higher than the maternal antibody titers of chickens from breeders vaccinated with the live NDV vaccine.

The effect of Marek's disease vaccination on the immunisation of day‐old chicks against Newcastle disease, using B1 and oil emulsion vaccine

Concurrent vaccination of one-day-old chicks with 2 x 10(5) 50% embryo infectious doses of live B1 Newcastle disease virus and 0.25 ml killed oil emulsion Newcastle disease vaccine produced satisfactory levels of circulating haemagglutination inhibiting antibody although the recipient chicks possessed titres of maternally derived antibody as high as 10 log(2). This effect was also seen when the chicks were given turkey herpesvirus for immunisation against Marek's disease. The satisfactory Newcastle disease antibody levels achieved by the vaccination programme did not fall below 5 log(2) during the first 20 weeks of the birds' 40 week life span. Re-vaccination with live B1 vaccine at 17-days-old did not boost antibody levels, but re-vaccination with oil emulsion vaccine at 9 weeks-old produced a rise from 7 log(2) to 11 log(2). These findings are considered to be significant in establishing and maintaining immunity to Newcastle disease for both broilers and laying hens, particularly in areas where the disease is endemic.