MXPA99005550A - In ovo vaccination against newcastle disease - Google Patents

Abstract

The present invention is concerned with a vaccine for in ovo vaccination of poultry against Newcastle Disease Infections. This vaccine contains Newcastle Disease Viruses of the strain with the internal indication NDW, deposited at CNCM (Institut Pasteur) under number I-781.

Description

IMMUNIZATION AGAINST NEWCASTLE'S DISEASE The present invention relates to a vaccine suitable for vaccination in ovo against an infection with Newcastle disease, with the use of a virus with Newcastle disease in the preparation of such vaccine, as well as with the protection of poultry against infection with Newcastle Disease by vaccination in ovo with a vaccine containing a series of viruses with the Ne castle disease.

Vaccination in ovo of vaccines containing viruses is described extensively by Sharma et al. (US Patent No. 4458630). In particular it teaches that the virus with Marek 's disease alive can be injected into the amniotic fluid inside the egg, after which the embryo becomes infected and the vaccine virus doubles to a high titer, which induces the formation of protective antibodies in the treated embryo. (Sharma, Avian Diseases 29, 1155, 1167-68 (1985)).

In US Patent No. 5427791 Ahmad et al. describes the embryonic vaccination against the Ne castle disease. Even, to provide a non-pathogenic attenuation of the virus with the live Ne castle disease (class?: DV-B1), the viruses are modified through the use of ethylmethane sulfonate (EMS).

Ref. 030518 One disadvantage of this type of modification is the fact that the EMS is a mutagen and that the vaccine is suspected to act as a mutagen as well, which is undesirable to regulate the administration of the vaccine. On the other hand, untreated NDV-B1 can not be applied for in ovo vaccination, since almost all embryos will die by injecting the eggs with this unmodified virus.

In addition, it has been found that the margin between the minimum effective dose and the maximum safety dose for these modified viruses is less than 10 (therefore less than logl). For practical purposes and in view of the errors as a result of production and due to losses during storage, this margin is too small.

Surprisingly it has been found that a preparation of the vaccine containing viruses with Newcastle disease of the NDW class is particularly suitable for in ovo application. Therefore the present invention relates to the use of Newcastle disease virus of the NDW class in in ovo poultry vaccination. As a further embodiment, the invention relates to the use of the Newcastle disease virus of the NDW class in the preparation of a vaccine suitable for in ovo administration to poultry.

Samples of the virus with Newcastle disease NDW class are deposited at the CNCM of the Institut Pateur under No. 781. See EP 351908.

Advantageously, the NDW class is administered in an amount of between 10"1 and 103 and more in particular in an amount between 10" 0.7 and 102-2 per egg.

To obtain the best results in the immunization, it was found that the NDW containing vaccine can be administered in ovo between 17 and 19 days of incubation, preferably after 18 days of incubation.

Example 1 Preparation of the NDW vaccine for in ovo administration A raw material of Working Semen Virus is prepared from a Master Semen Virus (deposited in the CNCM, Institut Pasteur under No. 1-781) by inoculation into the allantoic cavity of the embryonated SPF chicken eggs.

In the same way, the vaccine is produced by inoculation of the Working Semen Virus in the allantoic cavity of embryonated SPF eggs. After incubation, the allantoic fluid containing the vaccine virus is collected. The allantoic fluid is diluted and frozen and stored at -50 ° C.

Before filling, the allantoic fluid is thawed, then diluted to the required concentration of the vaccine virus, mixed with a stabilizer, filled into jars and dried by freezing.

Example 2 Safety of the NDW in ovo vaccine in SPF eggs The eggs of SPF are vaccinated at 18 days of incubation in the amnion by the method described by Sharma and Burmester (Avian Diseases ¿6. (1), 134-149) with the vaccine described in Example 1.

Six groups of eggs are vaccinated according to the scheme outlined in the following Table.

Table 1. Safety of in ovo vaccination of SPF eggs with NDW vaccine Conclusion: In ovo vaccination of SPF eggs at 18 days of embryonic development with the NDV vaccine is safe with a maximum dose between 101"2 and 102'2 of EID50 per egg.

Example 3 The safety of the NDW in ovo vaccine in commercial tender chicken eggs with maternal antibodies.

Commercial tender chicken eggs that have maternal antibodies are vaccinated at 18 days of incubation in the amnion by the method described by Sharma and Burmester.

(Avian Diseases 2 £ (1) / 134-149)) with the vaccine described in Example 1.

Eight groups of eggs are vaccinated according to the scheme outlined in the following Table.

Table 2. Safety of in ovo vaccination of commercial tender chicken eggs with NDW vaccine. Conclusion: In ovo vaccination of young chicken eggs with maternal antibodies is safe (no effect on incubation) up to a dose of at least 102 EID50 per egg.

Example 4 Efficacy of in ovo vaccination of SPF eggs with NDV vaccine The efficacy of the NDV vaccine prepared according to Example 1 is examined in the SPF eggs.

The parameters for protection are the antibody response after vaccination (haemagglutination inhibition test = HI test) and percentage of mortality after the test. The test virus is the Hertz 33/56 class of the Virus with Newcastle Disease, which is administered to each of the chickens in an amount of 105'0 of EID50.

Five groups of eggs are vaccinated according to the scheme summarized in the table below: Table 3: Efficacy of in ovo vaccination of SPF eggs.

Conclusion: In ovo vaccination of SPF eggs at 18 days of embryonic development with NDV vaccine is effective. A vaccine dose of approximately 10"0.7 per egg is the minimum effective dose for vaccination of NDV in ovo.

Example 5 Efficacy of in ovo vaccination with NDV vaccine of commercial tender chicken eggs with maternal antibodies The efficacy of the NDV vaccine prepared according to Example 1 is examined in commercial tender chicken eggs with maternal antibodies (HI titre of 5.1 at the first day of age).

The parameters for protection are the antibody response after vaccination (HI test) and the percentage of mortality after the test. The test virus is the Hertz 33/56 class of Virus with Newcastle Disease, which is administered to each of the chickens in an amount of 105-0 of EID50.

Three groups of eggs are vaccinated according to the scheme outlined in the table below: Table 4: Efficacy of in ovo vaccination in commercial tender chicken eggs.

Conclusion: In ovo vaccination with NDV vaccine of commercial tender chicken eggs at 18 days of embryonic development is effective. This is not influenced by the presence of maternal antibodies.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (9)

1. A vaccine for the vaccination in ovo of poultry against infections with Newcastle disease, characterized in that it comprises a virus that has the characteristics of the NDW class, an example of which is deposited in the CNCM (Institut Pasteur) under number 1-781.

2. A vaccine according to claim 1, characterized in that the viruses of the NDW class are administered in an amount between 10"1 and 103 of EID50 per egg.

3. A vaccine according to claim 1, characterized in that the viruses of the NDW class are administered in an amount between 10"° '7 and 102" 2 of EID50 per egg.

4. A vaccine according to claim 1, characterized in that the viruses of the NDW class are administered in ovo between 17 and 19 days of incubation.

5. A vaccine according to claim 1, characterized in that the viruses of the NDW class are administered in ovo at 18 days of incubation.

6. The use of a Virus with Newcastle Disease class NDW, deposited in the CNCM (Institut Pasteur) under number 1-781, in the preparation of an appropriate vaccine for in ovo vaccination.

7. A use according to claim 6, wherein the viruses of the NDW class are presented in an amount between 10"1 and 103 per egg.

8. The use according to claim 6, wherein the viruses of the NDW class are presented in an amount between 10"0-7 and 102-2 per egg.

9. A method to prevent or treat infections with the Newcastle disease in poultry, characterized in that it comprises the in ovo administration of a vaccine comprising a virus having the characteristics of the NDW class, an example of which is deposited in the CNCM (Institut Pasteur) under the number 1-781 .