Effect of maternal antibodies on the immune response to different canine parvovirus vaccines and antibody response to selected vaccines

Abstract

Canine parvovirus (CPV) is the main cause of gastroenteritis and mortalities in young dogs worldwide. Despite vaccination, the outbreaks of canine parvovirus infection occur in many countries including Sri Lanka. Interference caused by maternally derived antibodies (MDA) is a main reason for vaccination failure. Present study assessed the level of CPV specifc MDA in puppies prior to vaccination, the effect of MDA on the efficacy of different preparations of CPV vaccines and, evaluated the immunogenicity of selected CPV vaccines available commercially. Analysis of MDA in puppies born to vaccinated or unvaccinated mothers using commercially available point of care ELISA based test revealed the presence of protective levels of MDA titres at 8 weeks of age which can affect the immunogenicity of the vaccines containing inactivated virus or low viral titre (1000 HAU). The vaccines containing CCID 50 of 103-5 were able to induce antibody titres higher than protective level. Analysis of CPV-2 specifc antibody titres, two weeks after completing the primary CPV vaccination (16-18 weeks of age) revealed that the dogs who received the vaccines containing CPV-2 or CPV-2b strain with >105 CCID 50 induced significantly high levels of mean antibody titre (vaccine "B"- p value = 0.004; vaccine "D" - p value = 0.022; vaccine "F"- p value = 0.032) when compared to the vaccine containing 1000 HAU. In conclusion, it was evident that the interference of MDA on CPV vaccines could be circumvented by using a live attenuated CPV vaccine having a high viral dose of CPV. Low viral dose vaccines and inactivated vaccines are not suitable for primary vaccination as those could be interfered by maternal immunity.