Vaccination is the process of introducing an antigen (a killed, modified-live, or recombinant pathogen) into an animal's body to stimulate an immune response and create protective memory. Vaccines do not cure disease — they train the immune system to recognise and fight a specific pathogen rapidly if exposure occurs later, before the disease can take hold.
Vaccines are categorised as core (recommended for all pets regardless of lifestyle) and non-core (recommended based on individual risk and exposure). For dogs, core vaccines include DHPP (distemper, hepatitis, parvovirus, parainfluenza) and rabies. For cats, core vaccines include FVRCP (feline viral rhinotracheitis, calicivirus, panleukopenia) and rabies. Non-core vaccines include leptospirosis, Bordetella, and canine influenza for dogs; FeLV for cats at risk of outdoor exposure.
The puppy and kitten series of vaccinations exists because maternal antibodies passed from the mother to offspring interfere with vaccine effectiveness early in life — they neutralise the vaccine antigen before the immune system can build its own response. Multiple boosters at 3–4 week intervals are given until the maternal antibody levels fall sufficiently for the vaccine to work. The series is not complete until the final booster is given, typically around 16 weeks of age.
Adult vaccination schedules vary by vaccine and jurisdiction. Some vaccines (notably parvovirus and distemper) now have strong evidence supporting 3-year or longer intervals after the initial series in adults, rather than annual boosters. Rabies schedules are legally mandated and vary by location. Titer testing — measuring antibody levels — is increasingly accepted as an alternative to automatic re-vaccination for some core vaccines in pets with documented immunity.
📌 Key Facts
Core vaccines for dogs: DHPP + Rabies
Core vaccines for cats: FVRCP + Rabies
Why a series is needed: Maternal antibodies block early vaccine effectiveness
Adult booster intervals: Varies — some core vaccines every 3 years after initial series
Frequently Asked Questions about Vaccination
Q: Can my pet get the disease from the vaccine?
For killed (inactivated) vaccines, no — there is no live virus present. For modified-live vaccines, it is theoretically possible but extremely rare, as the virus has been weakened to the point where it cannot cause disease in a healthy immune system. A pet that is already ill or immunosuppressed when vaccinated may occasionally show mild signs.
Q: Why does my puppy need so many vaccinations in the first year?
The series of boosters in puppies is designed to ensure immunity is established as maternal antibodies wane. Maternal antibody levels vary between individual puppies in the same litter, so multiple boosters at 3-4 week intervals ensure that at least one dose lands when maternal antibody interference is low enough for the immune system to respond.
Q: How long after vaccination is my pet protected?
Protection typically develops 7–14 days after the final dose in a series. Until then, especially for puppies and kittens, full protection is not yet established. This is why keeping unvaccinated puppies away from unknown dogs and high-risk environments is important until 1–2 weeks after the final puppy booster.
⚠ Medical Disclaimer: This glossary entry is for educational purposes only
and does not constitute veterinary advice. Always consult a licensed veterinarian for diagnosis
and treatment of your pet's health conditions.