Back to Client Info Index
How Often Should We Vaccinate Dogs?
Reviewer Fiona Hickford, BVSc, MVSc, DACVIM
Title: Clinical use of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs
Author: Twark L, Dodds WJ
Journal: J Am Vet Med Assoc
Purpose of Study
Currently, a debate is ongoing regarding how frequently veterinarians should administer booster vaccinations. Studies in cats have shown that antibody titers against panleukopenia and respiratory (herpes and calici) viruses remain high and that cats appear to be protected (according to challenge experiments) for several years after vaccination. For this reason, some veterinarians no longer vaccinate cats annually. This has left veterinarians wondering what is an appropriate vaccination interval for dogs.
The objective of the study was to assess whether serum canine parvovirus and canine distemper virus antibody titers could be used to determine revaccination protocols in healthy dogs.
Immunofluorescent antibody (IFA) titers against canine parvovirus and canine distemper virus were determined in approximately 1400 serum samples from dogs of various ages. The date of most recent vaccine administration was evaluated when available. A subgroup of sera was tested by serum neutralization and hemagglutination inhibition techniques, and the titers were compared with the IFA results to determine a cut-off point at which the IFA titer could be deemed protective.
It was concluded that an IFA titer >/=1:5 was consistent with adequate antibody response. Approximately 95% of dogs had an adequate response to canine parvovirus and 98% had an adequate response to canine distemper virus. Approximately 93% of dogs still had adequate antibody titers against canine parvovirus and canine distemper virus >2 years after vaccine administration.
The study design was not really appropriate to fulfill the objective because dogs were not challenged with virus to prove protection. Also, less than one third of the serum samples were accompanied by information regarding the most recent vaccine administration; therefore, a large amount of data was missing, so how could one confidently determine an appropriate revaccination protocol? The study basically validated an IFA for canine parvovirus and canine distemper virus by comparing it to other techniques used to measure the same antibodies at a reference laboratory. The "cut-off" IFA titer, which implies protection, was determined by correlating IFA titers with those from this reference laboratory and then extrapolating from the laboratory's cut-off value. However, the method by which the reference laboratory determined whether a particular titer was protective was not describedwas it by challenge experiments? We must remember that although high titers generally correlate with protection, humoral immunity is merely one component of the immune system. Also, some dogs with low titers still may be protected by cell-mediated immunity or local immunity. Choosing a cut-off titer is not easy!
If one assumes that high antibody titers usually correlate with protection, then it appears that most dogs are protected for more than 2 years after vaccine administration; therefore, annual revaccination, as typically recommended by veterinarians, may not really be necessary.
Some pet owners and veterinarians may prefer to measure titers before deciding whether to give booster vaccines. A word of warning: each laboratory must standardize their own technique; they cannot merely use cut-off titers from other laboratories.
Does vaccine administration protect dogs against canine infectious hepatitis and other components of typical combination vaccines for dogs for >2 years? Data suggests that this is probably not the case for leptospirosis.
This study showed that most dogs have high titers against canine parvovirus and canine distemper virus for more than 2 years after vaccine administration. Therefore, if one assumes that high antibody titers usually correlate with protection, annual vaccination may not always be necessary in dogs.
Clinical use of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs
Objective-To assess whether serum canine parvovirus (CPV) and canine distemper virus (CDV) antibody titers can be used to determine revaccination protocols in healthy dogs. Design-Case series. Animals-1,441 dogs between 6 weeks and 17 years old. Procedure-CPV and CDV antibody titers in serum samples submitted to a commercial diagnostic laboratory were measured by use of indirect fluorescent antibody (IFA) tests. On the basis of parallel measurements of CPV and CDV serum antibody titers in 61 paired serum samples determined by use of hemagglutination inhibition and serum neutralization methods, respectively, we considered titers greater than or equal to 1:5 (IFA test) indicative of an adequate antibody response. Results-Age, breed, and sex were not significantly associated with adequate CPV- or CDV-specific antibody responses. Of 1,441 dogs, 1,370 (95.1%) had adequate and 71 (4.9%) had inadequate antibody responses to CPV, whereas 1,346 of 1,379 (97.6%) dogs had adequate and 33 (2.4%) had inadequate responses to CDV. Vaccination histories were available for 468 dogs (468 for CPV, 457 for CDV). interval between last vaccination and antibody measurement was 1 to 2 years for the majority (281/468; 60.0%) of dogs and 2 to 7 years for 142 of 468 (30.3%) dogs. interval was < 1 year in only 45 of 468 (9.6%) dogs. Conclusions and Clinical Relevance-The high prevalence of adequate antibody responses (CPV, 95.1%; CDV, 97.6%) in this large population of dogs suggests that annual revaccination against CPV and CDV may not be necessary.
DODDS WJ,HEMOPET & ANTECH DIAGNOST,;17672A COWAN AVE;IRVINE,CA 92614 USA.
Hemopet & Antech Diagnost, Irvine, CA 92614 USA.
JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION,217: (7) -1024 OCT 1 2000
A VETERINARY MEDICINE/ANIMAL HEALTH
AMER VETERINARY MEDICAL ASSOC
Unless otherwise indicated, all citations and abstracts are from Discovery Agent or Focus On: Veterinary Science and Medicine Copyright® 2000 by the Institute for Scientific Information®. All rights reserved. No portion of this data may be reproduced or transmitted in any form or by any means without the prior written permission of the publisher. Commentary provided courtesy of VetMedCenter and is not provided as part of Discovery Agent or Focus On: Veterinary Science and Medicine.
The majority of the information in this page is has been taken from VetMedCenter.com. For further information about this useful source of informtion follow the link or look, on the internet, at www.vetmedcenter.com.