Hie effects of vaccination timing on porcine circovirus type 2 viremia

摘要

Circumvent PCV M G2 (Merck Animal Health, Summit, NJ) is a combination porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae vaccine, which is labeled for either one or two dose regimens. The label directions for age at vaccination are 3 daysor older followed by a booster 21 days later (two dose regimen) or at 21 days or older (one dose regimen). With the two dose regimen, many producers perform the vaccination with other routine procedures such as processing and weaning. In some instances,the interval between the two vaccinations may be shorter than the label recommendation due to delayed processing, early weaning or both. In the literature there are multiple studies looking at dosing regimen and timing in relation to PCV2 viremia following vaccination. For instance in Cline, et al., it was found that there was no significance difference between vaccinating at 3 weeks of age versus 6 weeks of age with a one dose regimen.1 A study published by Opreiessnig, et al., found that there was a significant difference in the reduction of viremia when using a two versus a one dose vaccine regimen.2 The objective of this study was to determine the impact of vaccination timing, number of doses and interval on PCV2 viremia following vaccination.