Not an Emergency...Marek's in the Flock

[KAT Bird]

KAT, Nice find!  It's always a blessing to find new research articles.
I wonder how close they are to selling it?

I sent an email to Isabel M. Gimeno at North Carolina University. She was involved in the study of the new Bi-valent vaccine.

http://www.cvm.ncsu.edu/dphp/phm/gimeno_isabel.html

 

[seminolewind]

Kat, I hope he answers. That's a good idea!

 

[Nambroth]

I have had my ear to the ground about the new vaccine(s) in development, but haven't posted about them until there was more information. I'm glad you guys found it!

 

[seminolewind]

I think current information is hard to find, google adds tons of information links that are 10-20 years old.

 

[KAT Bird]

I sent an email to Isabel M. Gimeno at North Carolina University. She was involved in the study of the new Bi-valent vaccine.

http://www.cvm.ncsu.edu/dphp/phm/gimeno_isabel.html

 

[KAT Bird]

Dear Kellyanne,

this is not a commercial vaccine, just an experimental vaccine. It is not licensed to be used in any country so far. If any company decided to continue the studies and license it then it will be a cell-associated vaccine that needs to be stored in liquid nitrogen. The ways/routes of administration will be same as other MD vaccines.

Best wishes,

Isabel

 

[Nambroth]

Alas, that's about what I thought. Still, the poultry industry loses SO much money to Marek's every year that surely new vaccines will be developed for commercial use eventually.

 

[seminolewind]

Little do they know that most of us would be willing to be trying it for research's sake.

 

[KAT Bird]

This is interesting and something I will pursue with the USDA. I did tell them about our "group" and that many others may be interested in this depending on what he means by bleeding my birds. I hope he just means a normal blood draw! I will let you all know what I find out.


Thank you for contacting me about potential MDV field isolates. I would certainly be interested in receiving samples from backyard flocks in addition to commercial flocks. Are you able to bleed the birds yourself or have them bled by someone else? Do you still have the 3 unvaccinated birds that you didn't lose with the first 6? Isolating virus can be a challenge and our best chance is from birds that are visibly sick, but if your vaccine is currently giving protection, then the next best alternative would be the unvaccinated birds or the serotype 3 (HVT)-vaccinated birds.

Regarding your other questions, if you want to know the virulence of the virus strain, pathotyping is about your only option. It is unfortunately a long and laborious process, so we're only able to do a handful of field isolates each year. Results can take 4-6 months from the time the samples are submitted. PCR testing will only confirm that your birds are infected which is likely the case if it was confirmed by necropsy. MDV vaccines protect against developing disease, not infection. Also, it is very difficult to distinguish between virulent MDV and CVI988 vaccine by PCR. The vaccine in the link you provided is not commercially available. That vaccine candidate causes lymphoid atrophy in maternal antibody negative chickens which prevents regulatory approval. Current research is being done to try and prevent this problem.

If you're interested in sampling I can provide instructions.

 

[Nambroth]

This is interesting and something I will pursue with the USDA. I did tell them about our "group" and that many others may be interested in this depending on what he means by bleeding my birds. I hope he just means a normal blood draw! I will let you all know what I find out.


Thank you for contacting me about potential MDV field isolates. I would certainly be interested in receiving samples from backyard flocks in addition to commercial flocks. Are you able to bleed the birds yourself or have them bled by someone else? Do you still have the 3 unvaccinated birds that you didn't lose with the first 6? Isolating virus can be a challenge and our best chance is from birds that are visibly sick, but if your vaccine is currently giving protection, then the next best alternative would be the unvaccinated birds or the serotype 3 (HVT)-vaccinated birds.

Regarding your other questions, if you want to know the virulence of the virus strain, pathotyping is about your only option. It is unfortunately a long and laborious process, so we're only able to do a handful of field isolates each year. Results can take 4-6 months from the time the samples are submitted. PCR testing will only confirm that your birds are infected which is likely the case if it was confirmed by necropsy. MDV vaccines protect against developing disease, not infection. Also, it is very difficult to distinguish between virulent MDV and CVI988 vaccine by PCR. The vaccine in the link you provided is not commercially available. That vaccine candidate causes lymphoid atrophy in maternal antibody negative chickens which prevents regulatory approval. Current research is being done to try and prevent this problem.

If you're interested in sampling I can provide instructions.

I just read a paper that says that it's very, very hard to tell the difference via DNA PCR testing when a bird has had the Rispens vaccine-- that the vaccinated virus looks like MDV-1.

Anyhow I am going to the vet with my possible Marek's rooster tomorrow and I can ask her to assist in a blood draw, if you find anything out before I go. He had the HVT vaccine only.