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LABORATORIOS HIPRA S.A. makes available interesting
questions that we belive may be usefull to you:
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How does one choose between a 1-dose or 2-dose vaccination programme when vaccinating against M. hyopneumoniae?
It is generally expected that a 2-dose vaccination programme would present greater efficacy than one using a single dose. This is because the second dose of vaccine is able to induce a booster effect of animals’ immune systems. Furthermore, 2-dose vaccination programmes are able to overcome more efficaciously the barrier of maternal antibodies coming from colostrum, i.e., they reduce the risk of partial or total neutralisation of the vaccinal antigen. It is recommended that vaccination be delayed in 1-dose programmes so as to avoid partial or total neutralisation of the antigen, thereby reducing the risk of losing vaccinal activity.
It is essential, for each farm, to determine, by using serology and / or PCR, the dynamics of infection by Mycoplasma hyopneumoniae. It can generally be expected that vaccination with two doses is profitable on those farms on which the animals undergo very early infections (during lactation), early ones (during transition) or late ones (in the first few weeks after entering the fattening farm). Nevertheless, vaccination with a single dose will probably be profitable on those farms on which animals undergo very late infections.
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- Enzootic pneumonia: the disease
- Pathology: Enzootic pneumonia
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What type of vaccine for PRRS is recommended for nulliparous, seronegative gilts that enter a positive farm?
The indication to use one type of vaccine or another depends on the epidemiological situation with respect to PRRS of the farm the piglets come from and the type of handling they receive at the farm of destination.
The final purpose of vaccination is to give protective immunity to nulliparous animals before they gestate for the first time. Different options exist for accomplishing this according to the type of farm from which the pigs come and their destination i.e., whether the are positive farms or free of PRRS
Another factor to take into consideration is if the seronegative, nulliparous gilts are housed together with adult sows; they run the risk of becoming infected and, therefore, excreting virus. Consequently, on this type of farm (one that does not have separate buildings in which the nulliparous animals can adapt) the use of live vaccines is totally indicated for reducing viral excretion in case they become infected during gestation. The risk is reduced, therefore, that adult sows may suffer new outbreaks due to an increase in infection pressure (surrounding viral load).
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Do we obtain a good immune response in calves when they are vaccinated when 1-month old?
The standard recommendation, when vaccinating young calves with a tetravalent virical vaccine (e.g., against BVD, IBR, BRSV, PI-3), is to do the primary vaccination when they are 4 to 6 weeks old and a booster dose 3 or 4 weeks later. The motive for this recommendation is, on the one hand, to prevent the colostral antibodies, which are passively transferred to the calf after birth, from inactivating the vaccinal virus and compromising the response that the immune system must develop after vaccination and revaccination. On the other hand, it is also recommendable for heading off the period of greatest incidence of respiratory processes in young calves that usually increase as of this age.
Two important concepts must be kept in mind; one is the duration of the colostral antibodies and the other is the duration of colostral protection. Colostral antibodies can usually be detected up to 5 or 6 months of age, but the average life of these antibodies is only 4 to 5 weeks. This means the colostral antibodies are reduced by half just one month after birth. This is why vaccination is postponed until this age. It is when protection conferred by the cow has greatly diminished, the risk of infection of the calf and possibility of developing the disease are greater and vaccinal antigens are no longer neutralised and can optimally induce immunity.
Therefore, vaccination at 4 to 6 weeks and revaccination 3 to 4 weeks later means the vaccinal antigens develop a complete, detectable and serologically measurable immune response.
Related documents
- Bovine pathological processes
- Diagnostic kits
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How does one choose between a 1-dose or 2-dose vaccination programme when vaccinating against M. hyopneumoniae?
It is generally expected that a 2-dose vaccination programme would present greater efficacy than one using a single dose. This is because the second dose of vaccine is able to induce a booster effect of animals’ immune systems. Furthermore, 2-dose vaccination programmes are able to overcome more efficaciously the barrier of maternal antibodies coming from colostrum, i.e., they reduce the risk of partial or total neutralisation of the vaccinal antigen. It is recommended that vaccination be delayed in 1-dose programmes so as to avoid partial or total neutralisation of the antigen, thereby reducing the risk of losing vaccinal activity.
It is essential, for each farm, to determine, by using serology and / or PCR, the dynamics of infection by Mycoplasma hyopneumoniae. It can generally be expected that vaccination with two doses is profitable on those farms on which the animals undergo very early infections (during lactation), early ones (during transition) or late ones (in the first few weeks after entering the fattening farm). Nevertheless, vaccination with a single dose will probably be profitable on those farms on which animals undergo very late infections.
Related documents
- Enzootic pneumonia: the disease
- Pathology: Enzootic pneumonia
- Related products
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Can we differentiate serologically between animals vaccinated for BVD from those infected by a field virus?
It is possible to distinguish between animals vaccinated for BVD and those infected in the field by using the ELISA technique, which is directed specifically at the detection of antibodies against the p80 protein. This is a non-structural protein of BVD, and very stable among the different members of the Pestiviridae family (BVD, Border Disease, Swine fever, etc.). The presence of antibodies for this p80 protein means that the live virus (from the field) of BVD (or another pestivirus) has replicated in the animals and, therefore, the animal is or was infected. Consequently, when an inactivated vaccine is used, the ELISA method can detect Abs for p80 and distinguish between vaccinated animals and those infected by BVD in the field.
In addition, the IPI animals (immunotolerant and permanently infected by the BVD virus) usually give low or negative results for the ELISA-p80 but they are detectable when using direct techniques for identifying the virical antigen in blood leukocytes, skin, etc., or by molecular analysis by PCR of a sample of blood or serum.
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- Assessment of the vertical transmission of neospora caninum using a pre-colostrum and maternal serological study on diary farms
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- Pathology: BVD
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Why are there coryza vaccines containing only two, and others with three serotypes of Haemophilus paragallinarum?
Originally, the B serotype was not considered as a real serotype but as a group of variant strains coming from A and C serotypes that had lost some specific antigens. This is why there are still some vaccines that do not include B serotype strains. But now, this theory has been abandoned, since it is has been proven that there are B serotype strains fully pathogenic widely distributed. This is why it is necessary to include the three serotypes to obtain a fully efficacious vaccine and give the greatest protection against the different field isolates.
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- Pathology: Infectious coryza
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Do we obtain a good immune response in calves when they are vaccinated when 1-month old?
The standard recommendation, when vaccinating young calves with a tetravalent virical vaccine (e.g., against BVD, IBR, BRSV, PI-3), is to do the primary vaccination when they are 4 to 6 weeks old and a booster dose 3 or 4 weeks later. The motive for this recommendation is, on the one hand, to prevent the colostral antibodies, which are passively transferred to the calf after birth, from inactivating the vaccinal virus and compromising the response that the immune system must develop after vaccination and revaccination. On the other hand, it is also recommendable for heading off the period of greatest incidence of respiratory processes in young calves that usually increase as of this age.
Two important concepts must be kept in mind; one is the duration of the colostral antibodies and the other is the duration of colostral protection. Colostral antibodies can usually be detected up to 5 or 6 months of age, but the average life of these antibodies is only 4 to 5 weeks. This means the colostral antibodies are reduced by half just one month after birth. This is why vaccination is postponed until this age. It is when protection conferred by the cow has greatly diminished, the risk of infection of the calf and possibility of developing the disease are greater and vaccinal antigens are no longer neutralised and can optimally induce immunity.
Therefore, vaccination at 4 to 6 weeks and revaccination 3 to 4 weeks later means the vaccinal antigens develop a complete, detectable and serologically measurable immune response.
Related documents
- Bovine pathological processes
- Diagnostic kits
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