Q. If an animal receives only the first dose of a vaccine that needs two doses to immunize, will it have immunity?
No. A single dose of a two-dose vaccine like Leptospirosis vaccine will not provide immunity. The first dose is for priming the immune system. The second for boosting the immunity has to be given within 6 weeks; otherwise the series has to start over again. After those two doses, revaccination with a single dose can be done at any time.
Q. Can maternally derived antibodies (MDA) also block immunity to killed vaccines and prevent active immunization with MLV vaccines?
Yes. MDA can block certain killed vaccines, especially those that require two doses to immunize. With MLV vaccines, two doses are often recommended, particularly in young animals, to be sure one is given beyond the neutralizing period of MDA.
Q. How long after vaccination does an animal develop immunity that will prevent severe disease when the core vaccines are used?
This is dependent on the animal, the vaccine, and the disease.
· The fastest immunity is provided by canine distemper virus (CDV) vaccines -- MLV and recombinant canarypox virus vectored. The immune response starts within mins - hrs and provides protection within a day without interference from MDA.
· Immunity to canine parvovirus (CPV-2) develops after 3-5 days when an effective MLV vaccine is used.
· Canine adenovirus-2/hepatitis (CAV-2) MLV given parenterally provides immunity against CAV-1 in 5 to 7 days.
Q. Can dogs be “non-responders” and fail to develop an immune response to vaccines?
Yes. This is a genetic characteristic seen particularly in some breeds or dog families. Boosting them regularly will not produce measurable antibody. Some of these animals may be protected against disease by their cell-mediated and secretory immunity.
Q. Are there parvovirus and distemper virus field mutants that are not adequately protected by current MLV vaccines?
No. All the current CPV-2 and CDV vaccines provide protection from all known viral isolates, when tested experimentally as well as in the field. The current CPV-2 and CPV-2b vaccines provide both short and long term protection from challenge by the CPV-2c variant.
Q. Are serum antibody titres useful in determining vaccine immunity?
Yes. They are especially useful for CDV, CPV-2 and CAV-1 in the dog, FPV in the cat, and rabies virus in the cat and dog. Rabies titers, however, are often not acceptable to exempt individual animals from mandated rabies boosters in spite of medical justifcation. Serum antibody titers are of limited or no value for (many of) the other vaccines.
1 President, Hemopet, 938 Stanford Street, Santa Monica, CA 90403; 2 Chairman, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706.
* Excerpted from: AKC Health Foundation, St. Louis, MO, 2007; J Sm An Pract 48, 528–541, 2007; 5th IVVDC Conference , Madison, WI , 2009.
● Day MJ, Horzinek MC, Schultz RD. Guidelines for the vaccination of dogs and cats. J Sm An Pract, 48, 528-541 2007
● Dodds WJ. Vaccination protocols for dogs predisposed to vaccine reactions. J Am An Hosp Assoc 38: 1-4, 2001.
● Dodds WJ. Vaccine issues revisited: what’s really happening ? Proc Am Hol Vet Med Assoc, Tulsa, OK, 2007, pp 132-140.
● Paul MA (chair) et al. Report of the AAHA Canine Vaccine Task Force : 2006 AAHA Canine Vaccine Guidelines. J Am An Hosp Assoc 42:80-109, Mar-April 2006, 28 pp. www.aahanet.org
● Schultz R D Considerations in designing effective and safe vaccination programs for dogs. In: Carmichael LE (editor), Recent Advances in Canine Infectious Diseases. Intern Vet Inform Serv, 2000. www.ivis.org
● Schultz RD. Duration of immunity for canine and feline vaccines: a review. Vet Microbiol 117:75-79, 2006.
“CORE” CANINE VACCINES *
· Adenovirus (Hepatitis)**
* vaccines that every dog and cat should have
** immunity provided by a CAV-2 vaccine
CANINE VACCINE ADVERSE EVENTS *
· retrospective cohort study; 1.25 million dogs vaccinated at 360 veterinary hospitals
· 38 adverse events per 10,000 dogs vaccinated
· inversely related to dog weight
· vaccines prescribed on a 1-dose-fits-all basis, rather than by body weight.
· increased for dogs up to 2 yr of age, then declined
· greater for neutered versus sexually intact dogs
· increased as number of vaccines given together increased
· increased after the 3 rd or 4th vaccination
· genetic predisposition to adverse events documented
* from Moore et al, JAVMA 227:1102–1108, 2005
VACCINE CONCLUSIONS FOR CANINES *
Factors that increase risk of adverse events 3 days after vaccination:
· young adult age
· small-breed size
· multiple vaccines given per visit
These risks should be communicated to clients
* from Moore et al, JAVMA 227:1102–1108, 2005