Discussion created on 11/04/2011

Vaccines for Marek's disease

Forum: Cause of vaccination failure against Marek's disease

Dear poultry scientists, I would like to start with the new subject regarding possible vaccination failure in MD prophylaxis. From my actual experience nowadays in spite of frequent use of bivalent vaccines against MD (Rispens+HVT) or (SB1+HVT) the MDV strains with raised virulence are isolated from field cases of the disease. I know in some cases this may be due to the low hygiene conditions in farms. However I also consider in some cases farmers apply double vaccination with bivalent vaccines at the 1st and 7th day of chickens life. From my own study I found that in such cases I commonly detect DNA of virulent MDV strain and HVT strain but not Rispens in spite of proper vaccination of chickens. Therefore I am curious about your experience and explanations of this problem. Please fell free to add comments. Thank you.

Grzegorz Wozniakowski
Doctor of Veterinary Medicine
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Rudolf Hein Rudolf Hein
Consultant Micobiologist
November 14, 2011

Based on comment of burning feathers to reduce spread of MDV may be of any help but in addition the chicken "dander "(chicken dust) epidermal scales frm skin material and feather follicles showed to be a very important factor in the spread/transmission of MDV . The MDV is very stable over long period of time in chicken dander.

Re question of broiler vaccination : in US basically all broilers are vaccinated for MD not only to prevent immunosuppresion but to control Marek's disease condemnation at the processing plant .At all broiler processing plants official USDA inspectors are inspecting birds for condemnation including those caused by MD .(like skin lesions due to MDV)Any bird with MD lesions has to be discarded.

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Senthilkumar Senthilkumar
Veterinary Doctor
November 16, 2011
I have in my experience noted 2 reasons for the vaccination failure of bivalent vaccines.

1. The level of liquid nitrogen in the cannister during storage. The level of liquid nitrogen should be above the ampoule.

2. After the reconstitution of the vaccine, the vaccination should be completed within an hour .
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Dr Wisal M.Khan Dr Wisal M.Khan
Doctor of vet Med
November 17, 2011

@Senthikumar , yes you are right for the vaccince storage , The Nitrogen level should be above not only for the Bivalent but also for other types of the Marek's disease vaccince etc , other wise it will be useless to do spoiled vaccinations for any types of birds .
The time limit is important not only for the applying the vaccince but also when the vaccince ampule is taken from the Liquid Nitrogen Cannister and while for its prepartions .
Thanks

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December 1, 2011
marek outbeak, in m experience usually corelated with high chalenge in early rearing periode and together with poor management of brooding. same case usually found poor storage of vaccine, vaccine not completly deep in liquid nitrogen. double injected vaccine at hatchery is recommended for very hihg chalenge area and farm with very poor biosecurity, in order to avoid miss dose due to miss injected.
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Alkam Ahmad Alkam Ahmad
Agricultural Engineer
December 6, 2011
thank you all for your comments it was very useful to me and i want to add also from our experience that double shoot vaccination procedure was also helpful to eliminate this problem and also calibration of the vaccinator pressure and control the vaccination time to the optimum is also has an observed results.
thanks again
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December 8, 2011

Thank you for your all comments. I am always opened for the new issues or ideas regarding vaccination against MD. During the last week I isolated a few field strains from broiler chickens vaccinated against Marek's disease with HVT based vaccine. 

HVT in Poland seems to be not enought protection against the disease.
BTW if you would be interested in this subject please take a part in the scheduled conference.
Please check out the link
http://www.avianherpes2012.de/
Hope to see you there.
Greg

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November 8, 2019

Where can I get Marek vaccines?

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December 9, 2019

Double dose or re-vaccination after 6 hours in day old of broiler parents chicks of Marek's vaccine. Which is better? Please give suggestion about this. Is there any problem or side effect using double dose of MD response at day old?

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December 10, 2019

Most of the time it is the missed shots that cause problems. double dose does not prevent slips. 2nd vaccination ensures. Generally, the pfu available in Marek's vaccine are more than prescribed. most important is the brooder house. it the house had earlier incidence and not properly cleaned and rested, the chicks are exposed to field virus which reaches the receptors of the cell surface faster than the vaccine virus.
Bivalent vaccines and dispense stored in liquid nitrogen are more vulnerable for break in cold chain. check the ampoules for break in cold chain. generally, the companies keep the ampoules upside down. if vaccine is found at the narrow end, one should suspect break in cold chain.

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Muhammad Farooq Muhammad Farooq
M Sc (hons) Animal Nutrition
December 19, 2019
Any viral need to develop titer 2-3 days waste if double dose so early.mareks leukosis attack in later stage of bird esp in layer and breeder.
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December 25, 2019

Double dose in the same moment or revaccinate the flock after 6 hours, will not give any benefit, but try to give the right dose in the first shoot, more is a little better than less.

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Harun Ur Rashid Harun Ur Rashid
Doctor of Veterinary Medicine,Post Graduate Diploma in International Poultry Husbandry from Barneveld College The Netherlands.Post Graduate Diploma in Animal Feed Training Program fom Barneveld Colleg
March 1, 2020

Can I see a video of Marek's vaccination done properly?

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Harun Ur Rashid Harun Ur Rashid
Doctor of Veterinary Medicine,Post Graduate Diploma in International Poultry Husbandry from Barneveld College The Netherlands.Post Graduate Diploma in Animal Feed Training Program fom Barneveld Colleg
March 3, 2020
I want to know first correct way vaccination please.
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June 3, 2020
Hi. Can anyone tell me if there is an effect in efficacy against Marek's disease if dual insert vaccination procedure is administered on day old chicks?
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Nadim Amarin Nadim Amarin
Technical and Marketing manager - META Area - United Animal Health
June 3, 2020

Very interesting topic.

From our experience here below the main causes of vaccine failure and each one of them is a topic to discuss:

1. Vaccination storage/ handling/ transportation/administration
2. Time of thawing more than 90 sec.
3. Vaccine preparation or handling.
4. Time of vaccine consumption more than 1 hour.
5. Contamination in the vaccination equipment.
6. Poor vaccine administration ex. Non-vaccinated chicks,
7. Shaking the vaccine with the diluent vigorously… etc
8. Age of challenge – in endemic countries first two days of life.
9. Very virulent viruses/ new viruses

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June 9, 2020
Nadim Amarin well done
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June 9, 2020
Nadim Amarin

You have a really good points, but could you please add more explanation on number seven?
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June 4, 2020
India has not gone to rispense yet. SB1+HVT is doing well.
Proper handling of vaccine maintaining cold chain is very important.
Marek's vaccine virus has to reach the cell receptors before the field virus reaches. If the brooder houses are contaminated, the field virus moves faster. If the brooder house had an earlier incidence of Marek's cases, better delay the placement of chicks by over night by holding the chicks in the hatchery after the vaccination. This gives 12 hours lead to vaccine virus. No problem with breeder birds in delayed placement.
Slips while vaccination is a common cause while handling large size hatches like 100,000 chicks in one hatch. Repeat vaccine works mostly by protecting the slips in the first vaccination.
Some hatcheries are giving two doses at the hatchery with 12 hours gap before dispatch and report success.
repeating the vaccine after 7 days in the brooder house appears meaningless, if the hypothesis that field virus travels faster than the vaccine virus to the receptors is considered correct.
Marek's vaccine does not spread like other live vaccines (ND lasota or IB) from chick to chick. Hence correct dosing of each chick is a must. Not more than 4000 chicks should be alloted to one vaccinator (person) at a stretch. Over worked persons are more likely to slip.
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Dr.Prasad P Kulkarni Dr.Prasad P Kulkarni
M V Sc (Poultry)
June 18, 2020
Dr.Talapaneni.Kotaiah Sir, your overview also underlines need of the vector vaccines in prevalence of VVMD in India. We really do not have surveillance tool available & presence of which can be a pathfinder for this challenge. We in India have presence of almost all vaccine players known globally. Need is of the precision and tools to control re emerging issues like Marek's, CAV & always prevalent issues like Coryza, MD & IBD.
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Emmanuel Nwaotule Emmanuel Nwaotule
Higher Diploma In Animal Health and Husbandry
June 13, 2020
Doctor Kotaiah,you are very right. Once a vaccinator is tired,he or she is bound to make mistakes. This would definitely result in vaccination failure, considering the sizes of the chicks.
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June 18, 2020

Adetoro Abdulrahman, Chances of Marek's coming at such early age of 10 wks is very low. Second important thing is, we will continue to get lingering mortalities at least till 40 weeks of age. Many times these mortality typically shows tumors.
We have to confirm these things before coming to any conclusion.

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June 17, 2020

I'd witnessed a situation whereby birds started dying when there reached week 10. Me and my team couldn't fathom the real cause of this sudden death. Many tentative and confirmatory tests were carried out, but all gave no particular causal of this death. But with this I read on Dr. Talapanen's wall, could the death of these birds be as result of Marek's prophylaxis failure? Please I need enlightenment

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Dr. Mohammad Akram Dr. Mohammad Akram
Consultant Microbiologist
June 18, 2020

Following are the possible causes of failure of Marek's Disease (MD) Vaccine:-

INCOMPATIBLE VACCINE - Qualitatively i.e. not containing correct type of MD strain. Quantitative i.e. not containing enough PFU. Because MD control is becoming more and more complicated, therefore now higher number of vaccine virus ( 2000- 6000 PFU) needed. Initially in early seventies, only few hundreds of HVT freeze dried vaccine alone was controlling the disease but now even combination of 2 or 3 strains of MD viruses in thousands, some time unable to control the disease.

APPLICATION OF VACCINE - Cell associated vaccines are very delicate and need extra precautions to handle and apply in the hatchery. Some of the writers has already given the details. Maximum number of PFU i.e. more than 3000 from ampule of vaccine should be injected in the day old chicks to get required results.

TRANSPORTATION STRESS - Long distance transportation of chicks is causing stress and reducing the PFU of vaccine virus, therefore extra dose of vaccine usd at day old in hatchery could be helpful to get better protection.
When chick vehicles are passing from highly MD endemic area, contaminated air & dust can infect the chicks inside the vehicle. Mostly it is not possible to avoid this issue but try to select less poultry populated areas for transportation of chicks.

STRICT BIOSECURITY MEASURES OF REARING POULTRY HOUSES - This is the essential part of MD control. Presence of MD field virus in feather follicles,dust etc. of poorly cleaned & disinfected house can infect newly arrived chicks, before the production of immunity in first 2 weeks of age. This become one of the major cause of MD even in very well vaccinated chicks.
Prevention of early exposure is the most important factor to avoid vaccine failure.
Improved hygiene is the cost effective way of reducing the excessive losses of MD in vaccinated flocks.
Dr. M. Akram, Consultant Microbiologist, Micro Lab Karachi.

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Muhammad Kashif Muhammad Kashif
Veterinary Doctor
June 24, 2020
Dr. Mohammad Akram Dear Sir problem is with storage of the vaccines and many people relate this with PS stock MD is truly horizontally transmitted disease.
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Surinder Maini Surinder Maini
General Manager -Technical
June 18, 2020
Knowledgable people talk Lot of theory n Their experiance, they analyse every thing except one, that one item is the agenda behind the organisers intentions, to promote a new vaccine they send out articles, have seminars, scientists talk, these days use of technology webinar’s etc., no one is interested in developing good labs for proper n confirmatory diagnosis, they use their eyes from behind glasses like electron microscopes to identify new viruses like VVMD, VVND, Bird Flu etc., or blame the vaccine, or vaccinator, mismatching strain, cool chain or the breed. Please develop good n efficient laboratories, train people for collecting field samples, their analyst, referral laboratories with dedicated personnel, and stop guess work that has been done for 70 yrs in our industry
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Dr O S Alo Dr O S Alo
Veterinary Doctor
June 25, 2020
Surinder Maini They are drifting towards the place of value. The value chain tends to favour churning out new product rather than precision in diagnosis.More of product development than diagnostic practice.
The value chain is culprit.
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