Frequently Asked Questions on Cevac^® TRANSMUNE IBD

Why should I use Cevac Transmune IBD ?

• Correct IBD vaccination timing is critical to ensure effective vaccination of chickens against IBD.
• Vaccine virus will be neutralised by maternal derived antibodies (MDA) if the MDA level is higher than the breakthrough titer of the vaccine virus.
• Delaying the vaccination too long will create a window period where the chicken is highly susceptible to infection from the field virus.
• MDA level variations in a flock of chickens complicates this determination of the correct date.
• Administering Cevac^® Transmune IBD subcutaenous will ensure the vaccination of each bird at exactly the right time that that specific bird is susceptible for vaccine take.

Why is the Transmune vaccine complex not neutralised by maternal derived antibodies (MDA) while the natural virus, and other vaccine virusses are neutralised by the MDA? (After injection, during the trip to spleen, etc.)

• The Transmune vaccine-complex is a vaccine virus completely covered by a large number of Virus Protecting Immunoglobulins (VPI).
• There is therefor no more free epitopes on the virus vaccine for the MDA to link to and initiate the immune response.
• The immune-complex vaccine is thus fully surrounded by antibodies and therefor hidden from the immune system.

What is the nature of the links between the vaccine virus and the VPI?

• The links are non-covalent, electrostatic links.

What is the origin of the VPI?

• The VPI are produced by hyper-immunising SPF chickens with Cevac^® IBD L (containing the Winterfield 2512 vaccine strain virus, the same strain as in Transmune IBD)

What happens to the immune complex vaccine after injection? (Subcutaenous or In-ovo)

• In-Ovo :

          o  The vaccine is injected into the right breast, or into the amniotic fluid.

          o  If injected into the amniotic fluid, the amniotic fluid is swallowed by the embryo and the vaccine goes through the gut wall, and enters the blood stream.

• After ingestion, injection into the breast, or subcutaenous injection: 

          o  The vaccine spreads via the blood stream to all organs.

          o  In the medulla or germinal center of lymphoid organs, especially in the spleen, there are follicular dendritic cells that have the capacity to capture this complex vaccine.

          o  From this follicular dendritic cells, the virus is continuosly presented to the immune system of the chick.

          o  No immune response will be triggered untill the MDA has decreased to a low enough level to allow the replication of the vaccine virus and the subsequent immune response.

What will happen, if we inject chicks with very high MDA? Is it going to stop the vaccine virus replication?

• The mechanism of action is the same, but the onset of virus replication in the bursa will be delayed according to the level of MDA.
• This delay can take as long as 30 days, and Transmune will still be able to elicit an effective immune response.

If the vaccine is injected to chicks with very low MDA (or without), would there be immunosuppression?

• No, no immunosuppression is observed.
• VPI blocks the vaccine replication for 7 to 8 days, until the bursa is mature enough to tolerate an intermediate plus vaccine.
• The release of the vaccine is progressive, contrary to water vaccination where a huge amount of virus invades the body all at the same time.

Is MDA levels then still important, and can the vaccination of breeders with inactivated IBD vaccines be discontinued, if we are using Cevac Transmune IBD in the progeny?

• Yes, the MDA level is still very important, and no, the inactivated  IBD vaccination of the breeders can not be discontinued.
• Irrespective of the vaccine, the immune system needs time (a few days) before the immunity is at a protective level against IBD.
• There is always a susceptible window where only MDA can protect the chick.

How is the VPI of  the immune complex processed to release the vaccine virus?

• The non-covalent, electrostatic bonds is degraded over time, and this enables a constant presentation of vaccine virus to the immune system.
• The first vaccine virus will be released from the follicular dendritic cells from about 7 days after injection.
• It can take up to 30 days to release the full complement of vaccine virus to the immune system.

Can the Transmune vaccine virus spread from 1 bird to another or from 1 house to another ?

• Yes, once the virus is released from the complex vaccine and start to replicate in the bursa, the action follows exactly the action of Cevac^® IBD L (or any other IBD vaccine strain).
• Consequently, there is some spread of the vaccine.
• However, one should not adopt a "relaxing" attitude at the hatchery, relying on this spreading capacity to compensate for the lack of accuracy at injection time.
• There is always a window of susceptibility before the spread is actually able to trigger an immune response. Hence, any missed bird at the hatchery is a chick at risk.

Can I transmit Gumboro disease to my flock if I use Transmune IBD?

• Winterfield 2512 strain is genetically stable even after several back passages on birds.
• This is field proven by more than 30 years of successful use of this strain, the most widely used vaccine in the world.
• There is no risk to give Gumboro disease to chickens with Transmune.

Is there a risk of immunosuppression on my birds when using Cevac Transmune IBD?

• Trials have shown that birds were able to react properly against a NCD vaccine 4 days after vaccine take with W2512, at the maximum replication rate time of the vaccine.
• We can conclude therefor that there is no noticeable immunosuppression induced by Cevac^® Transmune IBD.
•  Millions of doses used worldwide are another evidence for the safety of Transmune IBD towards the immune functions

Why use an intermediate plus vaccine?

• Intermediate plus strains are the only strains able to protect against very virulent IBDV.
• Even several vaccinations with intermediate vaccines cannot provide appropriate protection.

Would it be possible to make the same kind of vaccine with intermediate strain instead of intermediate plus strain?

• Yes it is possible, and Ceva tested it at the beginning of the development of Cevac^® Transmune IBD.
• The choice of the intermediate plus strain was to eliminate the issue of which pathogenicity of field IBD virus is threatening the flocks
• Since Transmune is working against vvIBD, it is also working against subclinical IBD. So a company can use it all year long, whatever the IBD epidemiology in the field.

Can I use other vaccines on the farm after injection of Cevac^® Transmune IBD?

• Yes, Transmune IBD is fully compatible with all field vaccines.

In case of very strong vvIBD pressure on the farm, should the flock be revaccinated with Cevac^® IBD L after Transmune injection?

• In case of very strong vvIBD pressure, we recommend to use Transmune at day-old and Cevac IBD L on farm for 2 or 3 flocks and after that use Cevac^® Transmune alone.
• This is to ensure that the vvIBD field virus is rapidly replaced by the vaccine strain, as Transmune IBD L containes the same strain Winterfield 2512. 

Is it possible that the W2512 strain diffuses into the environment and creates problems on other farms with birds at that are of a different age?

• We acknowledge that the spread does exist when vaccine “take” takes place and the virus starts to actively replicate.
• If there are neighbouring farms housing birds of another age than the Transmune vaccinated ones, there are two scenario’s:

         o  If they are younger, and their MDA will neutralize the vaccine virus, or the chicken will be partly immunized by the spread virus

         o  If they are older, they could have already had  their own active immune response. Hence, a new stimulation will not have any effect.

What is going to happen if some chicks didn’t receive the vaccine? Could they get clinical symptoms of IBD?

• The best would be to vaccinate in the hatchery or by manual syringe on the farm the chicks that are suspected not  to have received Transmune.
• Because of the spreading capability of W2512 strain, the unvaccinated chicks will be vaccinated by their flock mates undergoing virus replication. This inter-chick vaccination may be sufficient depending on the % of unvaccinated chicks and on the field challenge (when it occurs and severity).

Is Cevac Transmune IBD better than Cevac IBD L ?

• On a composition point of view, they are made of the same Gumboro vaccine strain, Winterfield 2512
• However, Cevac^® Transmune IBD is an individually-injected vaccine at the hatchery, whereas Cevac IBD L is given by drinking water on the farm.
•  It means that the producer can achieve a far better control of the quality and uniformity of the immunisation of every batch of chickens, whereas the farm vaccination by drinking water obviously meets a lot of variability sources: accuracy of the vaccination date,poor quality of the water,water withholding time,uncertainty about the actual vaccine coverage of the flock, need for regular training and control of the farm staff

Which administration route is better, in ovo or subcutaneously at day-old ?

• The vaccine has been tested extensively using both recommended routes.
• The same quality of immunogenicity and tolerance has been achieved by any of the two routes. This is why the two routes are recommended in the field, as per the label.
• It is up to the broiler company or the hatchery to decide which route suits the local capacity, design, etc. the best.

Can I inject Cevac^® Broiler ND K to the same chick at the same time ?

• Extensive lab and field trials showed the satisfactory immune response elicited by the two vaccines after being injected under the skin of the neck of the same chicks.

Is the level of histopathological lesions of the bursa the same as with Cevac^® IBD L?

Yes exactly the same on individual basis.

What can we expect with regards to the evolution of bursa atrophy? On average, from what date can we start to see bursa’s changes?

• It' depends on the level of MDA:

         o  No MDA – At about 10 days

         o  Low MDA – At about 18 days

         o  Med MDA – At about 23 days

         o  High MDA – At about 28-32 days 

Does the release of the virus from the immune-complex start immediately ?

• Yes, as soon as it reaches the follicular dendritic cells of the spleen, the dislocation phenomenon begins.

In deep litter systems, is there any influence on Transmune efficacy?

• Deep litter systems increases the viral pressure. If you experience an IBD outbreak, you should:

         o  remove the litter

         o  clean and disinfect carefully

         o  use Cevac^® IBD L for one or two flocks in combination with Transmune, to ensure the replacement of the field virus with W2512

Is Transmune a GMO?

• No, this product is a classical IBD vaccine strain and antibodies.
• No compound has been genetically modified.

Does Transmune contain any bovine protein?

• No protein of bovine origin is used in this vaccine.

Is there any risk that Transmune is contaminated by AI virus?

• No. Every batch of our vaccines is produced according the Good Manufacturing Practices and checked for extraneous agents.
• Cevac^® Transmune IBD is pure and sterile when released.

When was the vaccine developed?

• Development started in 1995.
• The vaccine is produced on a large scale since 2001.

Why don't you sell Transmune in USA ?

• Because of Sanofi history, the US market was not open to Ceva vaccines.

Is Transmune registered in Western Europe?

• Transmune is registered in UK, Spain, Italy, France, Greece etc…

What diluent can I use in reconstituting the vaccine?

• The diluent must be sterile and suitable for injection.
• The diluents that have been validated for reconstituting Transmune are as follows:

          o  NaCl 0.9%

          o  Marek diluent

          o  De-ionized sterile water (bi- or triple distilled water)

          o  Water for injections.

What is the compatibility with Mareks vaccine?

• A lab trial was done proving no decrease in Cevac^® Transmune IBD efficacy when combined with Mareks vaccines (HVT from Intervet, Vineland and Fort Dodge, and HVT+ Rispens from Merial were tested).
• However we do not have lab data that proved the MD efficacy.
• The data we have, is field trial data from 20 million doses used in Brazil where Mareks vaccination is mandatory (1500 pfu HVT). This showed that no Mareks was observed during those trials (but we don’t have the data on slaughter condemnation for these trials).

May I use the MD diluent while NaCl 0.9 % is written on the label?

• Yes, the MD diluent is a cell nutritive media that doesn’t interfere with the vaccine efficacy

May I use the vaccine diluted to 0.2 ml while it is written 0.1 ml on the label?

• The vaccine can be used at 0.05ml (in ovo), 0.1 and 0.2 ml (SC) without any problem provided there is the full dose within the volume injected.

Must the vaccine be used within a specific time after vaccine reconstitution like with MD vaccines?

• The vaccine is much more resistant than HVT vaccine
• The reconstituted vaccine should be used within 2 hours after reconstitution
• Our tests have shown that our vaccine is actually surviving for 3 hours, but 2 hours gives a good safety margin.

What is going to happen if I inject Mareks/IBD Combination Vaccine with Transmune IBD?

• There is no negative interaction between the mild or intermediate strain in the association of MD+IBD with Cevac^® Transmune IBD.
• Most probably the mild or intermediate vaccine will be neutralized by MDA

What is the compatibility of Transmune IBD with Fowl Pox?

• In Brazil 14 million doses Transmune was used with HVT and Fowl Pox with very good field evidence of being fully compatible.
• The two virusses don’t have anything in common in terms of mechanism of action and target cells.
• The replication kinetics of the two virusses is also different since Transmune take is delayed and fowl pox take is immediate.

What is the compatibility with the blue dye?

• Blue dye is included at 1ml / 500ml to make vaccination efficacy easier.
• In Hungary trials with Transmune injected with blue dye had no impact on serology.

Can I combine Transmune IBD with antibiotics?

• Yes, with ceftiofur, gentamycin, amoxycillin, linco-spectin
• Not with enrofloxacine because of high pH
• There is no problem or interaction between Transmune IBD and antibiotics administered during the growing period.