Objective

This was a pivotal investigation to determine the duration of antibody responses to the viral antigens of Vanguard^TM vaccine (Pfizer Animal Health) in several field studies.

Method

A multi-centre serology study was conducted using client-owned dogs from clinics located in the USA (44), UK (14) and Canada (3). Three hundred and seventy-five dogs of various ages, breeds, sex, weights, lifestyles and time since last vaccination were enrolled in the study. Dogs were required to be healthy, with no history of those viral diseases and should not have been vaccinated for 12- 48 months. Additionally, dogs must have received at least a priming vaccination series approximately 2-7 weeks apart as a puppy and a booster vaccination approximately 8-16 months later. Dogs were considered to have antibody titres indicative of a protective serological response if their pre-vaccination serum levels were > 1:16 for CAV-1, > 1:32 for CDV, > 1:16 for CPi and > 1:80 for CPV (CVDL Guidelines) or if they demonstrated a 4-fold anamnestic response to revaccination.

Results

The pre-vaccination geometric mean titres were above levels indicative of a protective serological response for all viral antigens at all time intervals. The percentage of dogs that were classified as responders is shown in the table below:

Conclusion

Results from this study indicate that dogs of high and low disease exposure risk that have been previously vaccinated with Vanguard^TM have protective antibody titers to the core viral vaccines that persist up to and beyond 48 months.