Abstract
BACKGROUND: Maternally derived antibodies (MDA) have protection against canine distemper virus (CDV) in the first weeks of puppies' life. However, MDA decreases with age. The most important and effective factor on immunization is timely vaccination. But in recent years, there were some outbreaks of CDV among puppies in Iran and this problem could be related to vaccine failure. OBJECTIVES: The aim of this study is to evaluate the possible effect of MDA titre on vaccines against CDV and the efficacy of two commercial vaccines by using the enzyme-linked immunosorbent assay (ELISA). METHODS: In this regard, 24 healthy 8-week old terrier puppies were selected and divided into three identical groups based on a randomized, double-blind comparative trial. The control group was injected normal saline, and group A was vaccinated by the vaccine namely Biocan L (Bioveta, Czech Republic), and the group B was vaccinated by the other vaccine called Duramune Max 5 + LCI/GP (Fort Dodge Animal Health, USA). The vaccines were used for the puppies between 8 and 16 weeks of age and in every 4 weeks. RESULTS: The results showed that the response of both vaccines was satisfactory, and no significant difference was observed between them. Moreover, the MDA in the control group reached an unprotective level in all puppies prior to their 14 weeks of age. In the vaccinated groups, after the second vaccine, all puppies in both groups reached protective levels. DISCUSSION: This is the first study on evaluation of two commercial vaccines in changes of serum antibody titres against distemper in puppies in Iran. CONCLUSION: It is recommended that veterinarians during consulting use the ELISA to measure antibody titres to optimize the vaccination schedule and reduce the cost of vaccination failure. This is of paramount importance for puppies.