Kansas State University researchers have evaluated what appears to be a promising vaccine against porcine circovirus Type 2.
Of course, this common virus has gained increased attention because of its association with porcine circovirus associated diseases. However, not all hogs infected with PCV2 develop PCVAD. While much remains unknown about PCVAD, PCV2 can be excreted through nasal and ocular secretions, urine, feces, colostrum and semen.
Kansas State researchers conducted wean-to-finish clinical trials on a commercial hog farm in northeast Kansas using 485 pigs. The pigs were randomly divided into six groups at weaning and were vaccinated at three and six weeks of age. Some mortality rates prior to the trial had been as high as 20 percent.
The trial showed that the finishing stage’s mortality rate for vaccinated pigs was 50 percent less than for unvaccinated pigs. As for growth rate, the vaccinated pigs improved by about 10 percent. Also, vaccinated pigs on average were about 20 pounds heavier at the same days to market compared with unvaccinated pigs.
In a separate vaccine study in a commercial research finishing barn, mortality, growth rate and feed efficiency improvements were calculated at a $3.94-per-pig benefit.
“In addition to demonstrating the vaccine’s effectiveness, these studies highlight the devastating impact this virus can have on swine production,” says Steve Dritz, DVM, Kansas State researcher. “The results suggest that the vaccine will be an effective tool in controlling the disease in pigs caused by PCV2.”
Researchers are unsure, however, when the vaccine will be available for producer use. “The next steps are to continue to evaluate the vaccine under different field conditions to ensure that it is broadly applicable across the industry,” he notes. “We´re looking for more herds that have a less significant rise in mortality, but have infection with the virus to see if it is still economical to vaccinate.”
Research also is needed to further evaluate the virus’ molecular characteristics, and to develop diagnostic tools, Dritz says. Diagnostic tools will aid in the investigation of how the virus spreads from herd to herd or how the infection develops into the more severe forms of the disease.