Occasionally we have a puppy that has had a few of the puppy rounds of vaccinations still end up with a serious illness such as Parvovirus. That begs the question of how did this happen, why vaccinate if he still got sick? These are understandable questions and we would wonder the same if this happened to a child. We can only speculate why this happens, but again it comes down to how much risk do you want to take in not vaccinating your pet. Parvovirus in most cases kills your canine, especially a puppy. It may not seem like the vaccine worked, but if your puppy recovers from parvovirus, you can attribute that in part to the vaccinations already on board. They may have provided partial protection against the brunt of the virus. We see the same in college students who come down with measles, yet they had the measles vaccine. Below is a bit more information on puppy vaccinations.
Vaccination is particularly important in young animals because they are generally more susceptible to infection and tend to develop more significant disease. Although modified live vaccines can rarely revert to their pathogenic form and cause disease in the patient, maternal antibody interference is more likely to be the culprit in this situation and is the reason pediatric patients require a series of vaccinations. The maternal antibodies need to fall below a certain level before vaccination is effective. The level, which is variable, can occur between 8 and 16 weeks, depending on the mother’s vaccination history and the successful transfer of maternal antibodies via colostrum.
Unfortunately, the maternal antibodies can be high enough to block the immune response to the vaccine but not to protect the pet from an active infection. This window of susceptibility is a significant reason why an appropriately vaccinated pediatric patient can contract a disease despite being vaccinated.
Please take a serious look at why you should vaccinate your puppy. His life is precious.