The practice of giving an NSAID at the time of vaccination to reduce the risk of adverse vaccine reactions (low-grade fever, injection site reactions, etc.) is not an uncommon practice. The question as to the effect of the NSAID on the horse’s immune system’s ability to “respond” appropriately to a vaccine was the focus of a research project.
18 adult horses and 18 equine influenza-naïve (no previous vaccination for equine influenza) were used for this study. Three groups were formed, with six animals in each group: NSAID treatment and vaccination, no NSAID treatment and vaccination, and no NSAID treatment and no vaccination. Blood was drawn before initial vaccination and at weekly intervals four times after vaccination and analyzed to determine both the antibody response and the cell-mediated immune response.
The results indicated that NSAID uses resulted in a significant decrease in the antibody response to the vaccine as well as a reduced cellular immune response. The researchers concluded, “the administration of an NSAID at the time of vaccination reduced both the antibody and the cellular immune response to the vaccine. This occurred in both previously immune and naïve individuals”.
There are those horses out there that are quite “difficult” to vaccinate, and the use of NSAIDS at the time of vaccination is needed to prevent moderate to severe vaccine reactions. There may be no way to get around this issue, but one should keep in mind that these same horses may not have the protective antibody response if they are exposed to the influenza virus, for example, and extra precautions may be needed to keep these horses protected (the use of management methods that minimize exposure and promote good health, nutrition, and preventative care).
Scientific Article: Zoll, WM, et al. “Effect of Non-Steroidal Anti-Inflammatory Treatment
at the Time of Vaccination”. AAEP Proceedings, vol. 59, 2013, p. 53.