PCV2 vaccines

Enhancing immunity on farm

Vaccines towards PCV2 have proved to be exceptionally effective in controlling clinical signs of PMWS and possibly other PCV associated diseases.

Currently all vaccines are inactive and range from whole virus, subunit vaccines to the ORF 2 protein or a chimera of PCV1 and PCV2.

 

There are two major vaccination strategies:

Vaccine to the mother (sow and gilt) pre-farrowing.

This confirms enhanced antibody immunity to the piglet through colostrum.  The maternal acquired immunity is enhanced and is maintained beyond the normal 3 weeks to cover the weaner through the immediate post-weaning infection phase.  It has been recognized that piglets born to mothers with low immunity of PCV2 have lower colostrum antibody levels and appear to suffer clinical PMWS at a higher rate thus creating a litter effect.  Vaccination of the mother can be extremely effective at reducing the clinical signs of PMWS in the weaner/grower phase, but there is evidence that (some of) the pigs are not protected into the finishing phase, although the clinical signs are ameliorated.  However, the success of this vaccine regime relies on good colostral transfer thus excellent farrowing management.

Vaccine to the weaner before 5 weeks of age

These vaccines are again extremely effective at protecting the weaner to finisher from clinical signs of PMWS.  In addition they have been demonstrated to reduce the variability between pigs and enhance the growth rates of vaccinated pigs over the control unvaccinated animals.  However, the vaccine need to be administered to all piglets which can be a time consuming and frustrating enterprise.  This will be made easier by the development of multivalent vaccines for both Mycoplasma hyopneumoniae and PCV2 for example.

 

There is little difference being reported between the different vaccine types

As a general summary (meta-analysis IPVS 2008 papers)

 

Post-weaning mortality %

Difference in growth rates

Range

Average

Vaccinated

2-8%

4.5%

+ 30g/day

Unvaccinated

30-6%

9.1% (30% case omitted)

 

Papers reviewed IPVS 2008 P01:037,38,73,77,82,90,94,102,103,105 and OR01:25,37,46.

 

Vaccines:

Circoflex

Circumvent

Circovac

SuvaxynPCV2