Puppy Vaccination Schedule
The American Animal Hospital Association publishes one schedule for the core puppy series: start at 6–8 weeks, repeat every 2 to 4 weeks until the puppy is older than 16 weeks, then boost within a year.
Puppy shots chart, by age
| Age | What the AAHA publishes |
|---|---|
| 6–8 weeks | The earliest the AAHA starts the primary series — “the minimum age to begin the primary vaccination protocol in puppies”. |
| every 2–4 weeks after that | Revaccination, repeated at that interval rather than given once. |
| past 16 weeks | The series continues “until greater than 16 wk old” — 18–20 weeks is preferred where parvovirus or distemper risk is high. |
| within 1 year | A booster after the primary puppy series. |
| every 3 years | Interval boosters thereafter. |
Why so many shots?
Not because one dose is weak. A puppy carries antibodies from its mother, and those antibodies also block the vaccine. The AAHA writes that maternally derived antibodies against distemper “decline exponentially over time and are usually absent by 12–14 weeks of age”. Nobody knows the day it happens for a given puppy — so the series is repeated until an age where the block has almost certainly lifted. That is also why finishing early is not the same as being protected.
What this page does not tell you
Which vaccines your puppy needs. The AAHA separates core vaccines, recommended for every dog, from non-core ones that depend on where you live and what your dog does — and it does not publish a single list that fits every puppy. We publish the timing, which is the same for everyone, and leave the choice to the veterinarian who knows your dog. Rabies timing is also set by state law, not by this guideline.
Common questions
What is the puppy vaccination schedule?
The 2022 AAHA Canine Vaccination Guidelines put the start of the primary series at 6–8 weeks of age, with revaccination every 2 to 4 weeks until the puppy is older than 16 weeks — 18–20 weeks is preferred where parvovirus or distemper risk is high. A booster follows within 1 year, then every 3 years.
Why do puppies need several rounds of shots?
Not because one dose is weak. Puppies carry antibodies from their mother, and those same antibodies block the vaccine. The AAHA writes that maternally derived antibodies against distemper decline exponentially and are usually absent by 12–14 weeks of age — but nobody knows the exact day for a given puppy, so the series repeats until an age where the block has almost certainly lifted.
Which vaccines does my puppy need?
That is a question for your veterinarian, and this page does not answer it. The AAHA separates core vaccines, recommended for every dog, from non-core ones chosen according to where a dog lives and what it does — it publishes no single list that fits every puppy. Rabies timing is set by state law rather than by this guideline. What is the same for everyone is the timing, which is what this page publishes.
When is a puppy fully protected?
The AAHA does not publish a date, and neither do we. The schedule runs past 16 weeks precisely because the moment a puppy becomes able to respond varies from one animal to the next. Finishing the series is not the same as being protected, and only your veterinarian can judge your puppy's situation.
Next steps for a puppy
Which vaccines your puppy needs, and when, is a decision for your veterinarian — it depends on where you live, where your puppy goes and what it has already had. This page reports the schedule the AAHA publishes; it is not a prescription, and completing a series is not a guarantee of protection.
Verified on . See the method.