In a research trial at Iowa State University (ISU), results showed that two porcine circovirus type 2 (PCV2) vaccine regimens for both sows and pigs produced similar efficacies in reducing PCV2 viral loads and infectious levels in the growing pigs.

Interestingly, the ISU trial also showed that sow vaccination alone did produce lower protective antibody levels at challenge in piglets from dams immunized with one commercial vaccine (VAC2), compared to piglets from a second commercial vaccine (VAC1) used to immunize dams.

Vaccination of both sow and piglet with the same vaccine did not appear to produce any adverse reactions from PCV2 following the disease challenge.

The findings show that it is important for practitioners and producers to know that under the conditions of this study, vaccination of growing pigs with the same vaccine used in the dams did not negatively influence vaccine efficacy.

The two different commercially available PCV2 vaccines were used side by side. Seventy-eight piglets born to vaccinated or non-vaccinated sows were divided into eight groups. Groups with and without passively acquired antibodies for PCV2 were vaccinated at 21 days of age. All pigs except the negative control pigs were challenged with PCV2b at 35 days post-vaccination and necropsied at 21 days post-challenge.

The data showed that both vaccine regimens had similar results in reducing the level of PCV2 load in the growing pigs, which was measured by the amount of PCV2 antigen in tissues (Table 1), and the presence and amount of PCV2 DNA in serum (Figure 1) after PCV2 challenge.

Growing pigs vaccinated with VAC1 or VAC2 had similar levels of protective antibodies and lower levels of infection.

The main advantage of using a sow vaccination vs. a piglet vaccination is the reduction of cost and labor. One sow is vaccinated vs. the entire litter.

Funding for this research project was provided by the National Pork Board.

Researcher: Tanja Opriessnig, DVM, Iowa State University. For more information, contact Opriessnig by phone (515) 294-1950, fax (515) 294-6961 or e-mail tanjaopr@iastate.edu.