Maternal immunity and puppy vaccinations 

Early protection from mom to pup

The first form of mother’s milk that is produced after puppies are born is known as colostrum. Colostrum is rich with antibodies that get passed from the mother to the pups, providing them with temporary immunity to some diseases (such as adenovirus, parvovirus and distemper). 

This protection is critical for neonatal puppies but as they grow, protection will wane, and they will need vaccination to protect them from disease. However, timing of vaccination to optimize protection is complicated by the fact that maternal antibodies wane over time and any remaining maternal antibodies can actually interfere with the protection of the vaccines. If a puppy is vaccinated for certain diseases, such as parvovirus, when they still have maternal antibodies, the antibodies treat the vaccine as if it were a live virus, rendering the vaccine ineffective. 

Unfortunately, it is difficult to predict how much maternal protection each puppy will receive and for how long it will be protective. The amount of maternal antibodies that puppies receive can vary between litters and even between puppies of the same litter. Regardless, most puppies will no longer have protection from these maternal antibodies by 14 to 20 weeks of age.

As a result there is always a period where puppies are vulnerable to disease; they will not have enough maternal antibodies to give them protection from an actual infection, but they will have too many antibodies for a vaccine to be effective. There are different ways to try to give puppies the most protection during this “gap.”

Frequent, early vaccination

The most common way to address the protection gap is a population-based approach based on the earliest age at which maternal immunity is known to begin to wane and the latest age protection is known to last. Puppies are given a series of vaccines beginning at six to eight weeks of age, which is considered the age at which  protection from maternal antibodies begins to decline in some puppies. Additional vaccines are given every two to four weeks until puppies are 16 weeks old. These are not boosters, but an attempt to ensure that at least one of the vaccines is given at a time that best provides a puppy with lasting protection. 

Titer tests

A more individualized approach some dog owners or breeders may choose is to perform titer tests on their puppies to determine the best vaccination schedule. A titer test assesses the presence and amount of antibodies in the blood. When antibodies are low, a vaccine is more likely to be effective.

Titer tests can be a very good option for some dogs, especially if dogs have a history of not responding well to vaccines or are immunosuppressed. However, interpreting results can be challenging - they are only one measure of immune functioning. A high titer ratio can tell you if an animal currently has protection from disease, but they cannot tell you how long that protection might last. Conversely, a low titer test ratio is not always reliable, because immunity or protection is not solely dependent on antibody levels.

Frequent titer tests also require multiple blood draws on your puppies, and present potential stress due to the nature of the visit. Titers do not mean dogs are not vaccinated; they are a tool for determining when dogs need to be vaccinated.

Nomographs

A nomograph is a method of estimating the amount of maternal antibodies that will be passed from mom to pup. A blood sample is taken from the dam ideally in early pregnancy. There is currently one lab that conducts nomographs in the United States, at the School of Veterinary Medicine at the University of Madison-Wisconsin. Specific instructions on submission of blood samples can be found here.

You will receive results that provide you with the age ranges at which the maternal antibodies are predicted to be sufficiently low to vaccinate your puppies effectively. It is recommended to follow up with a titer test of the puppy at least two weeks after vaccination to verify the immune response to the vaccine. 

The nomograph test is an estimate and does not tell you the amount of antibodies received by each puppy, so they are not a definitive measure of protection. Nomographs assume that the puppy received adequate colostrum in the first few days of life. There are costs associated with getting the blood sample and the nomograph test. However, preliminary research has suggested that vaccine timing based on nomograph testing resulted in puppies with similar protection as those vaccinated under a traditional early vaccination schedule. 

Protecting puppies

When it comes to vaccinating puppies to protect them against deadly diseases, it’s a question of when, not if. Breeders and dog owners have options that can allow them the ability to provide their puppies with critical protection, and give them flexibility to help them decide the optimal vaccination schedule. We recommend working closely with your veterinarian to determine which of these methods will work best for you and your dogs.

Resources

VCA: Vaccination Failures in Dogs

Veterinary Information Network: Response of Puppies to Vaccination with Canine Distemper and Canine Parvovirus

Chastant, S., & Mila, H. (2019). Passive immune transfer in puppies. Animal Reproduction Science, 207, 162-170.

Wilson, S., Siedek, E., Thomas, A., King, V., Stirling, C., Plevová, E., ... & Sture, G. (2014). Influence of maternally-derived antibodies in 6-week old dogs for the efficacy of a new vaccine to protect dogs against virulent challenge with canine distemper virus, adenovirus or parvovirus. Trials in Vaccinology, 3, 107-113.