Introduction The avian influenza virus (AIV) H9N2 subtype was first characterized in 1966 as causing mild respiratory diseases in turkeys (Homme and Easterday, 1970) and, for the first decade after its isolation, was found only in shorebirds and mallards (Kawaoka, et al., 1988). However, after almost 50-years evolution and propagation, the H9N2 viruses have spread across most of the ea...
Dear Dr. Hossam
Thanks for your valuable article .
giving the AI vaccine in 4 to 6 days in the farm will give much better results in the titre of AI.
I agree with you that vaccination in the hatchery will give more uniformity , but the titre difference worth.
Dear Dr. Bakri
The AI study which you performed, was in poultry farms located in only 7 countries of Middle East! But you generalized the case and gave impression that all poultry farms are infected through out the region.
Scientifically, one has to be precise. Another issue, is this study for the publicity of the vaccine (Nobilis vaccine )..or it is purely scientific investigation?
My best regards
Dr. Mohammed ALDerbi
Dear Dr. Al Derbi, Your comments are highly appreciated. Yes, most of the farms in the area are using the vaccine. The infection has been confirmed in most of the Middle East countries, Asian and North Africa. My study is aimed to help farmers see if the vaccine will help or not because poultry farmers were losing a lot and they need to know results of using the vaccine in the field. Just for your information, more than 95% from the integration breeder & layer farms in the area are using the vaccine and more than 75% from broiler farms, also. There are many good companies producing this vaccine and I am sure they have good results also.
Dear Dr.Husam,
Thanks for sharing your expertise study and updating us !
Any updates of availability of AI vaccines as bi or trivalent along with ND/IB?
With best regards,
Dr.M.Saravanan
I do enjoy this discussion which is very enlightening and thank you very much to the author I share the opinion of Husam Bakri that vaccination at Hatchery is safer than postponing AI vaccination to about 10 Days on the shed. This is also applicable for ND Hb1 as it is safer to administer it in the Hatchery than on the farm to avoid seeding the litter with life vaccine What are your views on the use of reconbinant rH5MD vaccine for the protection of H5N1 and Mareks at the Hatchery level ?does Eduardo Lucio believe that this could solve his fear on Marek's antigen interaction in Ai immune responses I believe that in endemic zones that approve Ai vaccination, it would be safer to administer the vaccine at the Hatchery level.
Thanks to the author of this article. These days, the H9N2 were found in West Africa. I know veterinary services will not be agree with farmers to vaccinate flocks. It will be a great challenge for this part of Africa. Wait and see.
Dear Dolo, First thank you for your message. We have faced the same issue at our area and now most of the countries at our area using the vaccine with great impact for poultry industry .
Wish you all the best and please feel free to contact me any time if you need help in regard to this subject.
Thank you Dr Bakri for raising an important but lesser discussed issue of H9N2 LPAI.
I have recently published a review of this problem in Asia and Indian subcontinent in International Hatchery Practice (Volume 31 Number 2 (2017). I would like to share the same with fellow professionals.
Kindly go to the link below.
http://www.positiveaction.info/digital/IHP/2017/IHP_31_2/pdf/IHP_31_2.pdf
and follow on to page 11/36. Regards
I feel enlightened with the information on vaccination being followed in the middle east.
The vaccination is being discouraged because of the Mutational nature of the virus. Today's vaccine may not work tomorrow. Shedding of virus from the vaccinated & infected birds increases virus presence in the environment. The new strains may through a bigger challenge. Second reason, the Zoonotic aspect, where the pandamonium from the mutated strains is fore seen by the experts.
Many countries have started vaccination much earlier and the human cases seem to be increasing in those countries. What is the perception of the vaccinating countries on this?
Many vaccines available. 1. The Killed auto vaccines prepared on an emergency basis from the virus collected from the area, where int incidence is noticed.
2. The standard killed vaccines prepared against H9N8 or H5N2 etc. Being manufactured and sold by vaccine manufacturing companies.
3. The recombinant vaccines where the DNA of AI virus is mounted on the HVT marek's and administered to embryos or day old chicks on a continuous basis.
Can the experts through some light on the efficacy of using the above. I am looking for more information on recombinent vaccines, which can be used on a regular preventive basis, if the give early protection without shedding.
Dear Kotaiah, First thank you for your information and I totally agree with your information, that's why 2 year back I have re isolated H9N2 from 3 countries to see if there is any change from the vaccine strain. Lucky we found them still the same vaccine virus. The reasons sometimes you see problems in flocks even the vaccine has been used is we do have other challenges like ND and IB variant strains. Honestly, hardly in these days to find one disease challenging the poultry industry that why we are strongly advising farmers to do lab tests to see what other diseases playing a role.
Just for your information lucky middle east area so far does not have H5 challenge.
Thank you Dr Bakri for your efforts in poultry field .
Here in Egypt we have a big number of H9N2 infections in all poultry flocks most of these flocks were vaccinated against H9N2 two shots or three shots the used vaccine may be autovaccine prepared from virus isolated from our locality or vaccine of any of multi-national company.
Dr. Bakri did you have any survey about H9N2 in Egypt?
Dear Dr. Khaled,
All my survey was for middle east area and North Africa , Egypt was not included , but I know from different labs that H9N2 in Egypt is the same what we have found at our area. This is the same strain used most of the international companies used in their vaccines.
But as I mentioned before we need to know if there is any other diseases playing a role at the same time , also to be sure about vaccination application and also lab follow up is a must to be sure how the vaccines are responding.
All the best
Bakri
cher docteur BAKRI je souhaiterais avoir votre avis sur la vaccination avec H9N2 intervet que safait peu de temps qu'ont vaccine en ALGERIE a jour 1 et a 7 jour ont fesant des ELISA a 28 jours ont a des titres entre 3000-5000 sur le tier de l'elevage et les deux tier des titres de 150-300 pourquoi il n'ya pas une homogenite des reponces et est ce que votre souche vaccinale et proche de la souche ALGERINNE
merci
Dear Dr. Bouayad,
Thank you for your message. can you please send in English as my French language not good . This will be easy for me to under stand your question well.
All the best
Bakri
Dear Doctor BAKRI I would like to have your opinion on the vaccination with H9N2 intervet that was done recently in ALGERIA on day 1 and at 7 days, doing ELISA at 28 days, having titers between 3000-5000 on the tier of the livestock and the two tier of titers of 150-300. Why there is no homogeneity of the responses and is what your vaccine strain and close to the Algerian strain
Thank you.
Dear Bouchard, First point you need to look to it when you do not have homogeneity is vaccine application, second the best to evaluate the vaccine is to do HI test which more specific. Regarding the strain yes the strain we are using is matching with the field strain.
My advice if you need to evaluate the vaccine in HI or Eisa tests to colect the samples as follow: Day one, 10, 20 and day of the slaughter. From these results you can see how the titer will develop and when. But I strongly advice to do HI test .
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