Avian Influenza H9N2 in the Middle East Countries
Dear Dr. Yousef,
Thank you for your questions.
1- We hade 3 new isolation on 2013 from different countries and we found that they are 93% - 95% close to the vaccines strain. From my field experience, the vaccine did a great job to control the AI, specially in layer and breeder. Regarding using the vaccine and not getting good protection, specially in broiler, the following reasons are playing main roles:
1-Biosecurity is not good.
2- If AI infection before 3 weeks in this case. vaccine will not help as the protection from the killed vaccine will be after 3 weeks. we have seen this cases in many areas.
3- Vaccine application. During my hatcheries vaccination audit, I have seen many cases with the % of the proper vaccination at day one is not more than 60%, in this case 40% are not protected.
We have farmers using the vaccine in high challenge with very good results, this showed that AI vaccines from most of the good international companies giving good protections.
Regarding titer question. Can you please give me more explanation.
All the best.
Bakri
Dear Dr. Husam,
There are some questions I will ask you:
1. To obtain a high viral titer, how many virus particles of AI H9N2 should be inoculated into embryonated eggs?
2. Can H9N2 virus cause dwarf and curling in embryo?
Dear Entang,
1-Thank you for your massage and hope you are doing well. Honestly, I do not have any data on this, but according to the potency test, every dose has 7.0 Log HI unite.
2- The only sure information I can reply is when you challenge SPF birds by spray method with AI H9, the virus showed clinical signs and mortality.
All the best.
Import of avian influenza vaccines into India is banned by government of India.
Dear sir,
Hope you are fine.
1. What is the similarity percentage of this isolates A/Chicken/Bangladesh/VP01/2006 (H9N2) & your vaccine isolates.
2. Please told me the pathogenic,antigenic & genetic properties of vaccine strain.
Md. Zahid Hossain First, thank you for your questions .
1- I have 23 AI isolation from our area to see how much they are similar to the vaccine strain. Results showed that the lowest % was 85 which is from my field point of view most of the vaccines are giving good immunity against AI filed strains.
2- Regarding the pathogenic of AI, we have found on ICPI test was zero but when it comes with IB or ND the pathogenic was high.
This problem is everywhere in the world. Where birds are better managed with good nutritious feed and better preventive vaccination, with strict biosecurity methods are able to withstand the viral outbreaks. When the immunity levels are not maintained properly for ND, and IB then AI manifests in severe farm. Good managemental practices always protect the birds from many diseases.
Hangzhou DE Mark Industrial Co Ltd
Dear Dr.Husam,
There are some research papers represent that there is gene re assortments from H5 and H7 in H9N2 Virus in recent years therefore on AI vaccines China is doing a lot of research and work and their strains are closer to current field strains gives 80 to 85% protections. Please comment on this point. In my opinion, vaccine strains produced in the last 7 years are not so much closer to new vaccine strains.
Dr. Mujahid Kamran Thank you for your comments. We do have good experience on H9 vaccine in our area more than H5 & H7. Honestly what is going on in the flock vaccinated with H9 and no good results is due early H9 infection which the vaccine did not start giving immunity. I do have PCR results showing AI infection at 9 days and 5 days, in this case, no way the vaccine will give good results, that why you think that we have different H9 strain than the vaccine one.
Dear Dr.Husam thank you for very prompt reply, as you seen H9 outbreak at day 09 and 05. What about MDA role in broiler? And please suggest vaccination day with inactivated vaccines.
Dr.Mujahid Kamran In our area we are importing hatching eggs from countries not using AIh9 in the Breeder that's why MDA zero also hatching eggs from vaccinated flocks comes with different MDA due to different breeder ages.
United States
