Experimental Efficacy of a Novel Combined Vaccine of Porcine Circovirus Types 2a/d, and .

BACKGROUND

The efficacy of a novel combined vaccine targeting porcine circovirus types 2a/d (PCV2a/d), , and was evaluated in a controlled challenge study.

METHODS

A total of 45 pigs were randomly allocated into nine groups (five pigs per group). Vaccinated groups received a single 2 mL intramuscular dose of the combined vaccine and were subsequently challenged with PCV2a, PCV2d, , and . Unvaccinated groups received a single 2 mL intramuscular dose of phosphate-buffered saline (0.01 M, pH 7.4). Growth performance, systemic adaptive immune (humoral and cellular) responses, viremia, laryngeal and nasal mycoplasma loads, and histopathological lesions were assessed.

RESULTS

Vaccinated pigs exhibited enhanced growth performance and elicited systemic immune responses, including both humoral and cellular immunity, against all four pathogens. Vaccination also significantly reduced viremia, mycoplasmal loads in laryngeal and nasal swabs, and the severity of associated lesions compared with unvaccinated controls.

CONCLUSIONS

These results indicated that the combined vaccine was efficacious and conferred protection against PCV2a, PCV2d, , and challenge under experimental conditions. This combined vaccine represented an effective strategy to enhance growth performance and control complex co-infection in swine populations.