Serological response to administration of Brucella abortus strain RB51 vaccine in beef and dairy heifers, using needle-free and standard needle-based injection systems

Abstract

More than four million doses of Brucella abortus strain RB51 (SRB51) are administered in the United States every year. Accidental autoinoculation of humans has the potential to result in local and systemic symptoms; therefore, investigation of alternative delivery methods is warranted. The objective of this study was to compare the immunologic responses of four to eight-month-old beef and dairy heifers to vaccination with 1010 colony-forming units of SRB51, delivered either by standard needle-and-syringe system or needle-free injection system. There was no difference in the 30-day SRB51 antibody response to the two vaccination methods, and no difference in response between beef and dairy heifers. These data demonstrate that the humoral immune response of heifers to vaccination with SRB51 using a needle-free injection system is similar to the response obtained with a standard needle system. Further studies to define the cellular immune response and protection against infection are recommended before this administration method is considered for routine use.