ABSTRACT
The efficacy of porcine recombinant interleukin-12 (prIL-12) as an adjuvant to stimulate immunity was investigated in pigs vaccinated against porcine reproductive and respiratory syndrome virus (PRRSV). Porcine recombinant IL-12 was cloned and expressed in the insect baculovirus system. Thirty pigs were randomly allocated to five groups, and individual pigs were injected with PRRSV modified live virus with and without coadministration of prIL2; PRRSV killed virus with and without coadministration of prIL-12; or prIL-12 only (control). The effect of prIL-12 was evaluated through monitoring of humoral and cell-mediated immune (CMI) responses. Results indicated that the killed virus given in conjunction with prlL-12 induced humoral and CMI responses of similar magnitude to those of the modified live virus. However, without prIL-12, the immunologic response to vaccination with the killed virus vaccine was poor and similar to that of controls.