The cost is small compared to the cost of disease without use of the vaccine. Kirk Clark, professor of swine herd health in the School of Veterinary Medicine, says that although most pork producers vaccinate their animals, some have been asking questions about the recent research suggesting that vaccinations aren't necessary. We thought all along that this was wrong, and now we have the research to refute it. According to Schinckel, it is true that the growth in pigs does slow down after vaccinations, but it is a short-term effect. For a few days after the immunization they might have a slight fever, and they don't feel like eating as much.
Immunization slows down the time to market by about four days.
A diseased animal takes up to 43 days longer to go to attain market weight. The hogs were randomly assigned to pens in the Purdue hog facility. During the study, seven pigs died, six from the control group and one of the intensely vaccinated group. Pigs were vaccinated against streptococcus , haemophilus , E. coli , bordetella , salmonella , swine influenza virus, mycoplasma and Actinobacillus pleuropneumonea bacteria. It took the vaccinated pigs three to six days longer than the unvaccinated, quarantined pigs to reach market weight.