WHY IS BOOSTER VACCINATION NECESSARY?

FIRST VACCINE

First vaccine ensures the primary exposure of newborn to antigens/foreign proteins. This dose of vaccine is also called priming dose.

BOOSTER VACCINE

Normally, a puppy/kitten acquires passive immunity from its mother through milk in the form of maternal antibodies. This maternal immunity interferes with vaccine-dependent immunity. This results in the overall nullification of the effect of a vaccine. Hence, after first vaccination, most puppies/kittens do not develop immunity to the concerned viruses or bacteria. To overcome this "nullification" effect of maternal immunity, it is therefore necessary to give repeated doses of vaccine. This repeat dose of vaccine is called booster. More the number of boosters, more effective is the immunity.

DURATION OF BOOSTERS

Boosters are necessary as long as the body of a puppy/kitten has maternal antibodies (which is usually till 3 months of age). Hence after 3 months less number of boosters are needed (1 is sufficient).