Risk factors for inadequate antibody response to primary rabies vaccination in dogs under one year of age

• Published in: PLoS neglected tropical diseases Vol. 11; no. 7; p. e0005761
• Main Authors: Wallace, Ryan M, Pees, Anna, Blanton, Jesse B, Moore, Susan M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 31.07.2017; Public Library of Science (PLoS)
• Subjects: Adequacy; Age; Analysis; Animals; Antibodies, Viral - blood; Antibody Formation; Antibody response; Biology and Life Sciences; Blood; Disease control; Disease prevention; Dog Diseases - immunology; Dog Diseases - prevention & control; Dog Diseases - virology; Dogs; Dosage and administration; Failure analysis; Failure rates; Female; Health aspects; Health risk assessment; History; Immune response; Immunization, Secondary; Immunoglobulins; Laboratories; Linear Models; Male; Medicine and Health Sciences; Multivariate Analysis; Pets; Prevention; Probability theory; Public health; Rabies; Rabies - immunology; Rabies - prevention & control; Rabies - veterinary; Rabies vaccines; Rabies Vaccines - administration & dosage; Risk analysis; Risk Factors; Serum; Time Factors; Tropical diseases; United States; Vaccination; Vaccines; Variance analysis; Wildlife conservation; Atlanta Georgia; Georgia; Kansas; United States > US
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0005761

Ensuring the adequacy of response to rabies vaccination in dogs is important, particularly in the context of pet travel. Few studies have examined the factors associated with dogs' failure to achieve an adequate antibody titer after vaccination (0.5 IU/ml). This study evaluated rabies antibody titers in dogs after primary vaccination. Dogs under one year of age whose serum was submitted to a reference laboratory for routine diagnostics, and which had no prior documented history of vaccination were enrolled (n = 8,011). Geometric mean titers (GMT) were calculated and univariate analysis was performed to assess factors associated with failure to achieve 0.5 IU/mL. Dogs vaccinated at >16 weeks of age had a significantly higher GMT compared to dogs vaccinated at a younger age (1.64 IU/ml, 1.57-1.72, ANOVA p < 0.01). There was no statistical difference in GMT between dogs vaccinated <12 weeks and dogs vaccinated 12-16 weeks (1.22 IU/ml and 1.21 IU/ml). The majority of dogs failed to reach an adequate titer within the first 3 days of primary vaccination; failure rates were also high if the interval from vaccination to titer check was greater than 90 days. Over 90% of dogs that failed primary vaccination were able to achieve adequate titers after booster vaccination. The ideal timing for blood draw is 8-30 days after primary vaccination. In the event of a failure, most dogs will achieve an adequate serologic response upon a repeat titer (in the absence of booster vaccination). Booster vaccination after failure provided the highest probability of an acceptable titer.