What is a modified-live vaccine?
In a modified-live or live-attenuated vaccine, the causative organism (virus, bacterium, etc.) has been weakened or altered so that it is no longer harmful or virulent, but is still capable of stimulating protective immunity when injected or otherwise administered.
What is a killed vaccine?
With a killed vaccine, the causative organism has been killed or inactivated to render it harmless. Killed vaccines often need a helper or adjuvant included in the vaccine to stimulate a long-lasting immune response.
Which is better: a live or killed vaccine?
Both have advantages and disadvantages.The choice of which vaccine is better for your dog will depend on its individual circumstances. Your veterinarian will consider these circumstances when choosing the appropriate vaccine for your pet.
Why are vaccines administered by injection?
Some vaccines are given locally, for example into the nose, but most require injection so that the maximum take-up of vaccine by the white cells and stimulation of the immune system is achieved. Some vaccines are injected subcutaneously or just under the skin, others are injected into the muscles or intramuscularly. Injections may look easy, but your veterinarian considers many variables before they are administered.
Which vaccines are needed in dogs?
Depending on your locality, some infections may be more or less likely. The range of vaccines available includes rabies, distemper, adenovirus / infectious canine hepatitis, parvovirus, leptospirosis, parainfluenza, coronavirus, Lyme disease, and Bordetella bronchiseptica (for details on these diseases, see our handouts on each individual topic). These vaccines are often available in combinations that can be given in one dose. Combination vaccines are convenient and avoid extra injections for your dog, but sometimes separation of vaccines is advisable. Your veterinarian will advise you on the appropriate vaccines for your pet based on your dog’s relative risks and specific lifestyle.
“Core” Vaccines – Recommended for all puppies and dogs by the American Animal Hospital Association (AAHA) Canine Vaccine Task Force:
Canine distemper virus
Canine parvovirus
Canine adenovirus-2 (hepatitis)
Rabies virus
“Non-Core” Vaccines – Recommended for puppies and dogs in special circumstances, dependent on the exposure risk of an individual dog by the American Animal Hospital Association (AAHA) Canine Vaccine Task Force:
Distemper-measles virus
Leptospira spp.
Borrelia burgdorferi or Lyme disease
Canine parainfluenza virus
Bordetella bronchiseptica or “Kennel Cough”
What is maternal immunity?
Newborn animals have not yet had a chance to make their own immunity so they need protection against infections present in their environment. They receive this immunity from their mother, as maternal antibodies. Part of this “passive immunity” is transferred across the placenta while the pup is still in the uterus, but most of it is transferred in the first milk or colostrum. This maternal immunity is only temporary. It declines steadily over the first few weeks of life and is largely gone by twelve weeks. The rate of decline is variable, depending on many factors.
Why is more than one dose of vaccine given to pups?
There are two reasons. First, without complicated testing it is impossible to know when a pup has lost the passive protection it gets from its mother. An early decline in a puppy’s maternal antibody can leave it susceptible to infection at a very young age: a strong maternal immunity can actually interfere with early vaccination (see our handout Vaccination Failure). Second, particularly with killed vaccines, the first dose is a “priming” dose, and the second dose boosts the response to a higher, longer-lasting level of immunity.
Why does my dog need to be revaccinated?
In most properly vaccinated dogs, the immunity should last more than a year, and often several years. However, immunity does decline with time and this decline rate varies with individuals. To maintain the best immunity in a reasonable way, revaccinations have proven very successful. Because the vaccines we use are continuously improving, some do not need to be given as often, depending on individual circumstances. Most dogs with low-risk lifestyles can be vaccinated every three years with the “core” vaccines and as needed for any “non-core” vaccines (most non-core vaccines require annual boosters). Your veterinarian will discuss the need and frequency of booster vaccinations for your dog based on your pet’s needs and lifestyle.
