Fig. 1.

Mucosal vaccination with adjuvant rescued pigs from clinical PRRS with reduced gross lung pathology to a virulent PRRSV challenge. Pigs were unvaccinated (n = 9) or vaccinated (n = 9) with PRRS-MLV+ Mtb WCL and challenged with PRRSV MN184 on day post-immunization (DPI) 21 and then three pigs from each group were euthanized on day post-challenge (DPC) 15, 30, and 60. (A) Body weight of pigs was monitored on every third day post-challenge for 4 wks. Percentage body weight gain of individual pig was calculated by considering the weight of the pig at DPC 0 as 100%. (B) A representative lung picture of an unvaccinated or vaccinated and PRRSV challenged and then euthanized at DPC 15 is shown. (C) Gross lung lesion scores present in all the pig lung lobes at DPC 15, 30 and 60 were scored using a standard procedure. Each data point represents the average body weight gain from nine and six pigs ± SEM at DPC 15 and 30, respectively, and each bar represents the average lung lesion score from three pigs ± SEM. Asterisk denotes a statistically significant difference (P < 0.05) between unvaccinated vs. vaccinated and PRRSV challenged pigs.