Comparative efficacy of three commercial PCV2 vaccines in conventionally reared pigs.

The aim of this study was to compare the efficacy of three commercial porcine circovirus type 2 (PCV2) vaccines. Twenty 3-week old pigs were injected with one of three different vaccines, A, B, C, or were unvaccinated controls. Pigs in group A were given a second dose at 6 weeks of age according to the manufacturer's protocol. Antibody titers in all pigs declined gradually, but increased sharply by 22 weeks of age. Viremia in the three vaccinated groups at 22 weeks of age was significantly less than in the control group. The average daily gains of pigs in groups A-C, and in controls were 0.81 ± 0.03, 0.80 ± 0.05, 0.78 ± 0.04, and 0.74 ± 0.05 kg, respectively. It was concluded that PCV2 vaccine reduced viremia and improved weight gain, but differences in weight gain among vaccinated groups were not statistically significant.

An immunoperoxidase monolayer assay for the detection of antibodies against swine influenza virus.

An immunoperoxidase monolayer assay (IPMA) has been developed to detect antibodies against swine influenza A virus (SIV) in pig sera. The test was evaluated by using sequential sera from pigs experimentally infected with H1N1 subtype of SIV. Two hundred field serum samples that had been examined by the hemagglutination inhibition (HI) test were also tested. Antibodies specific to SIV were detected as early as 3 days postinoculation (dpi) in the IPMA test as compared with 7 dpi by the HI test. Unlike HI, no serum treatment was required in the IPMA test. Regardless of the virus used in the test, IPMA detected antibodies to both H1N1 and H3N2 subtypes of SIV whereas HI detects antibodies against either H1N1 or H3N2, depending upon the virus used in the test. Results of this study indicate that IPMA is a useful test for screening of pig sera for SIV antibodies.