Prevention and treatment of sub-clinical PCVD

1. A method for the prophylaxis and treatment of a sub-clinical PCV2 infection in an individual animal, comprising the step of once administering a therapeutically effective amount of an immunogenic composition comprising a PCV2 ORF2 protein wherein said sub-clinical PCV2 infection is characterized by the lack of overt signs of typical clinical symptoms and at least one additional criteria selected from the group consisting of:

a. a viral load below 10 6 genomic copies of PCV2 per ml serum;

b. a sample of 1 ml serum or 1 mg tissue of such a swine comprises a detectable amount of below 10 6 PCV2 genome equivalents; or

c. no or minimal tissue lesions.

2. The method of claim 1 , wherein the treatment in an individual or group of swine provides at least one result selected from the group consisting of:

a) an enhanced weight gain of those swine in fattening;

b) a reduction of loss of weight gain in swine sub-clinically infected with PCV2;

c) a reduction of virus shedding in swine sub-clinically infected with PCV2;

d) a reduction of the duration of viremia in swine animals sub-clinically infected with PCV2;

e) a reduction of the number of swine with a viral load comprised between 10 4 to 10 6 genome copies per ml serum in a group of swine sub-clinically infected with PCV2;

f) an increase of the average weight gain in a swine or a group of swine sub-clinically infected with PCV2; and/or

g) the reduction of the morbidity rate within a sub-clinically infected group of swine or the reduction of the mortality rate within a sub-clinically infected group of swine.

3. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition is accomplished in 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 accomplished in a swine during fattening.

5. The method of claim 1 , wherein the step of once administering a therapeutically effective amount of said immunogenic composition is accomplished in a young animal of 1 to 22 days old.

6. The method of claim 1 , wherein the effective amount of said immunogenic composition is 0.2 to about 400 μg/ml of the final immunogenic composition (μg/ml).

7. The method of claim 1 , wherein the effective amount of said immunogenic composition is 0.3 to about 200 μg/ml of the final immunogenic composition (μg/ml).

8. The method of claim 1 , wherein said ORF2 protein of PCV2 is a recombinant ORF2 protein of PCV2.

9. The method of claim 1 , wherein said ORF2 protein of PCV2 is a recombinant baculovirus expressed ORF2 protein of PCV2.

10. The method of claim 1 , wherein the immunogenic composition further comprises at least one veterinary-acceptable carrier selected from the group consisting of: a solvent, a dispersion media, a coating, an adjuvant, a stabilizing agent, a diluent, a preservative, an antibacterial and/or antifungal agent, an isotonic agent, or an adsorption delaying agent.

11. The method of claim 9 , wherein the adjuvant is an oil in water emulsion.