“Boosters” is a concept that is often misunderstood by pet owners. Biologically-speaking, in administering a booster vaccination, your pet’s doctor is seeking to initiate an anamnestic response from the immune system. Anamnestic comes from the Greek word anamnesis, meaning “a recalling.”
When a “first” vaccination is given by the veterinarian, the body is notified to induce the immune system to begin producing antibodies to the diseases from which the vaccine is designed to protect. Over the next several weeks the immune system works to build protection higher and higher. The physical evidence we see is soreness, mopiness and even low-grade fever during the 24-48-hour period immediately following vaccination. Initial vaccinations confer little immunity, but the process has to begin somewhere. Puppies and kittens should have their first vaccinations along with an examination at six weeks of age. If, as sometimes occurs, older animals fail to start on schedule, they should begin vaccinations as soon as possible.
During the next few weeks the immune system’s response matures to develop more and more protection. Part of that maturation response enables the immunity to be developed further when booster vaccinations are given.
In order for the response to boosters to be strong, they must arrive on a schedule of not less than three weeks and not more than four weeks from the date of the first vaccinations. Going beyond that four-week point (or another schedule specified by your pet’s doctor) will cause the immune system to “forget” the first vaccinations. Under those circumstances the series must begin again with two additional visits.
Even after the second set of vaccinations is administered, protection is not immediate. Increased immune system response occurs in the weeks following the booster vaccinations, and a time period of two to four weeks must pass before protection from disease is maximized. Therefore, your pet should not be allowed to associate with animals who might be ill, or those of unknown health and vaccination status.
The term “boosters” can also apply to a pet’s annual vaccinations, as well as any vaccines administered every six months, as Bordetella vaccines sometimes are. Dogs who board in kennels, are exposed to other dogs in dog shows and competitions and others who are open to communicable disease may experience frequent Bordetella vaccine administration.
Clients sometimes ask, as we have the syringes in hand, “Those are the boosters, aren’t they?”
Booster vaccinations are actually the same vaccines that were administered the first time. If they were not, the body would not recognize them in order to have an anamnestic response. Instead, the immune system would see them as something totally new. Therefore, “boosters” and “first vaccinations” are physically the same. It’s the timing that makes the difference.
See you tomorrow, Dr. Randolph.