Adjuvant effects of sulfolipo-cyclodextrin in a squalane-in-water and water-in-mineral oil emulsions for BHV-1 vaccines in cattle

The antibody and cell mediated immune responses induced by BHV-1 were analy sed in cattle after vaccination and challenge exposure to the virulent stra in LA of BHV-1. Animals were vaccinated intramuscularly (IM) with inactivat ed virus vaccines against BHV-1 containing either a water in mineral oil ad juvant (W/O), a water in mineral oil adjuvant plus Avridine (W/O O + Avridi ne) or sulfolipo-cyclodextrin in squalane in-water emulsion (SL-CD/S/W). No significant differences were registered in the antibody response induced b y the three evaluated vaccines. However, the BHV-1 specific cell-mediated i mmunite response was stronger and appeared earlier when SL-CD/S/W was inclu ded in the formulation. The efficacy of the vaccines was also evaluated aft er intranasal challenge of the calves with a virulent BHV-1 LA strain. Anim als vaccinated with SL-CD/S/W had reduced virus excretion and clinical symp toms compared with the mock-vaccinated animals. Comparison of levels of BHV -1 specific IgG2 and IgG1 with virus shedding revealed that, regardless of the adjuvant administered, animals showing BHV-1 specific IgG2/IgG1 ratios higher than 1 were those with a significant lower number of individuals she dding virus. Additionally, animals vaccinated with SL-CD/S/W presented no p ost-vaccinal reactions. These factors, combined with the higher efficacy an d the ease of manipulation of the biodegradable oil, makes the vaccine form ulated with this new adjuvant an important contribution for the veterinary vaccines industry. (C) 2000 Elsevier Science Ltd. All rights reserved.