Prevention and treatment of sub-clinical PCVD
The present invention relates to the use of an immunogenic composition comprising a porcine circovirus type 2 (PCV2) antigen for the prevention and treatment of sub-clinical PCV2 infection in animals, preferably in pigs.
1. A method for the prophylaxis and treatment of subclinical PCV2 infection in an individual swine, comprising the step of once administering a therapeutically effective amount of an immunogenic composition comprising a PCV2 ORF2 protein wherein the treatment of a sub-clinical PCV2 infection in an individual swine or a group of swine results in:
a. an enhanced weight gain of those swine in fattening,
b. a reduction of loss of weight gain in swine subclinically infected with PCV2,
c. a reduction of virus shedding in swine subclinically infected with PCV2,
d. a reduction of the duration of viremia in swine sub-clinically infected with PCV2,
e. a reduction of the number of swine with viral load comprised between 10 4 to 10 6 genome copies per ml serum in a swine sub-clinically infected with PCV2,
f. an increase of the average weight gain in a swine sub-clinically infected with PCV2, and/or
g. the reduction of the morbidity rate within a sub-clinically infected swine or the reduction of the mortality rate within a sub-clinically infected group of swine,
wherein said sub-clinical PCV2 infection is characterized in that the viral load in a sub-clinically infected swine is below 10 6 genomic copies of PCV2 per ml serum and that a sample of 1 ml serum or 1 mg tissue of such a swine comprises a detectable amount of PCV2 genome equivalents.
2. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition results in an enhanced weight gain of the swine in fattening or in reduction of the number of animals with viral load comprised between 10 4 to 10 6 genome copies per ml serum.
3. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition is administered to a swine wherein at the time of administration, said swine is seropositive for PCV2 and/or has anti-PCV2 antibody titer of more than 1:1000.
4. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition is administered to a swine 1 to 20 days old.
5. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition is administered to a swine intramuscularly or intranasally.
6. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition is to be administered for reduction of loss of weight gain in a swine subclinically infected with PCV2.
7. The method of claim 2 , wherein the average weight gain is increased in weeks 10 to 22 of age by more than 1.5 kg as compared to a swine that has not received an administration of the immunogenic composition.
8. The method of claim 1 , wherein the therapeutically effective amount of said immunogenic composition is to be administered for reduction of viral load comprised between 10 4 to 10 6 genome copies per ml serum in a swine sub-clinically infected with PCV2.
9. The method of claim 1 , wherein the therapeutically effective amount of said immunogenic composition is to be administered for increasing average weight gain in a swine sub-clinically infected with PCV2 or for reduction of the viral load comprised between 10 4 to 10 6 genome copies per ml serum.
10. The method of claim 1 , wherein the therapeutically effective amount of said immunogenic composition is to be administered for the reduction of the morbidity rate within a sub-clinically infected swine or for the reduction of the mortality rate within a sub-clinically infected swine.
11. The method of claim 1 , wherein said ORF2 protein of PCV-2 is a recombinant baculovirus expressed ORF-2 protein of PCV2.