Can we vaccinate nursing mothers?

Question: 

The shelter I work for is trying to establish an improved vaccination protocol. The question has come up about whether or not it is safe to vaccinate dogs and cats that are currently nursing young?

Answer: 

Thank you for your question as it is actually frequently asked. The short answer is yes it appears safe to vaccinate nursing queens and bitches with modified live vaccines. This is not always done if the mother can be kept in a clean, uncrowded foster home where the risk of e.g. parvo is very low.
The reason to wait is to avoid causing any mild discomfort (e.g. temporary fever or malaise) in the mother that might interfere with her nursing. This concern is theoretical but valid if you are dealing with a private pet. The nature of the environment of shelters and most foster homes is that the risk of contracting such deadly diseases as parvo (panleukopenia) is too high.
Obviously, it will do the mother and her kittens/puppies no good if she contracts an infectious disease; the whole family will likely succumb.
Therefore, we do recommend that all nursing mothers receive a modified live FVRCP or DHPP on intake too.

The question of whether it is safe to vaccinate pregnant animals is a little more controversial. Again, a lot of the concern is theoretical not proven with studies or even seen much in pratice. If pregnant animals are not spayed/aborted or sent IMMEDIATELY to clean foster homes then we also recommend vaccinating them.