The old puppy shots schedule - taught to me and other aspiring vets at vet school decades ago - went like this:
We need to protect puppies from as young an age as possible. So let’s give them their first vaccination at six weeks of age. However, every puppy gets a big dose of protective antibodies in the first suckle (of colostrum) from its mother. These antibodies wane over time but are still relatively high in the puppy’s body at six weeks of age and tend to neutralize vaccinations given at that time.
So, in short, the first vaccination given at six weeks of age, is very often not effective.
Because we can’t rely on it, we then recommended another two rounds of vaccine at around 10 and again at 14 weeks of age.
Now we know better.
Research has revealed that over-vaccinating puppies predisposes them to autoimmunity diseases without offering better protection from disease.
The new puppy shots schedule goes like this:
By eight weeks of age the level of antibodies from their first feed from mom has dropped low enough to make vaccination at this time highly effective in around 95% of puppies. Since we can rely on it, only one follow up puppy vaccination is needed, around four weeks later (ie at 12 weeks old). Giving a booster 12 months later has been found to then protect the puppy for life.
If it wasn’t so important to get the puppy out there socializing with its new owners by eight weeks of age I would keep it a week or so longer and delay the first vaccination to 9 to 10 weeks of age. This would bring its effectiveness up close to 100%. However, there is only a narrow timeframe of opportunity to expose puppies to the world and owners are the best placed to give their puppies the one on one attention doing this well requires.
The biggest threat to life by far for any young dog are behavioural issues stemming from inadequate socialization at the right age!
Keeping your puppy separated from the world until its last puppy shots is a recipe for disaster. Socialization can and should be full-on during this time, and can be done safely.
Owing to political considerations, in Australia the Australian Veterinary Association has compromised with the profession. While acknowledging the effectiveness of the new protocol for puppy shots, the AVA’s recommendation is to give boosters every 3 years after the 12 month shot. Some veterinarians still stick to the old regime
I routinely only vaccinate puppies for Distemper, Canine Hepatitis, and Parvovirus. In this case, more is not necessarily better. Giving combinations of multiple vaccines has been shown to be harmful to the development of a strong immune system in puppies. However, if you plan to use kennel boarding services in the future, additional vaccination against Kennel Cough will be required.
In some areas vaccination against Leptospirosis and Rabies is also recommended. However, poor immune response and adverse reactions to Leptospirosis vaccine are relatively common. Also, the strains that cause disease in your area may not be covered in the vaccine unless matched with local testing. According to pet vaccine expert Dr Dodds, who is an advocate of minimising puppy shots to only what is necessary, the current ideal puppy shots protocol is as follows:
9-10 Weeks Old: Distemper and Parvovirus (modified live vaccine)
14-16 Weeks: Repeat of Distemper and Parvovirus (modified live vaccine)
20 Weeks or Older (if allowed by law to delay this long): Rabies
1 Year: Optional booster with modified live vaccine of Distemper and Parvovirus (a Vet can check the level of antibodies in the dog's serum and vaccinate if the titre is below desirable levels.)
1 Year after the initial dose: Rabies (killed vaccine) separated by three to four weeks from the distemper-parvovirus booster
Regarding further boosters after the puppy shots, It is desireable to check antibody titres every three years thereafter to check if revaccination is necessary.