Reduced Risk of Allergic Reactions in Dogs to a New Tetravalent Canine Leptospirosis Vaccine

Introduction
A new tetravalent liquid inactivated leptospirosis vaccine (nobivac® L4 – MSD animal Health) has recently been authorized within Europe. it contains antigens of four differ- ent Leptospira interrogans (sensu lato) serogroups and is efficacious against relevant serovars of serogroups Canicola, icterohaemorrhagiae, australis and Grippotyphosa (1). it is recognized that all vaccines carry a risk of causing allergic reactions (2) and studies have shown that bovine serum albumin (BSa), is an important allergenic excipient in this respect (3,4). the VaccipuretM filtration process is unique for MSD vaccines and actively removes excess BSa from the final product. in the following study the BSa con- tent of several bivalent European canine leptospirosis vaccines was compared with the BSa content of the new nobivac L4 vaccine.

Materials and methods
Samples from different batches of four bivalent leptospirosis vaccines were assayed for BSa content (pierce® BCa protein assay – thermo Scientific) alongside nobivac L4 as shown in the table below.

Results and conclusions
As shown in the table below, the BSa content of all five batches of competitors a, B and C was much higher than that of any of the nobivac Lepto or nobivac L4 batches. assuming that all of these batches are representative of the respective licensed prod- ucts this implies that nobivac Lepto and nobivac L4 contain the lowest amount of potentially allergenic BSa. it can be concluded that after vaccination of dogs with nobi- vac Lepto or nobivac L4 there is a likely to be a lower risk of allergic reactions.