Parvovirus vaccination information from webmd.
 

There are several threads on yorkietalk.com about puppies being infected with parvovirus despite vaccinations, and I did a little research. The best information I found came from webmd: Dog Parvovirus Symptoms, Treatments, and Causes

Vaccinations starting by 8 weeks of age, will prevent most (but not all) cases of parvovirus infection. During the first weeks of life, puppies are protected by high levels of maternal antibodies. As these levels decline, there is a period lasting from two to four weeks during which puppies are susceptible to infection because vaccinations have not yet fully taken effect. This susceptible period varies from pup to pup, which is why pups anywhere between 6 and 20 weeks age can be especially susceptible to parvo. Nearly all apparent vaccination failures are due to exposure during this susceptible period.

Newer high titer-low passage vaccines are narrowing the window of susceptibility. These modified live virus vaccines contain a higher number of virus particles (high titer), which are less attenuated (low passage; a low passage vaccine contains virus particles that have been less attenuated, or weakened, than those in the average vaccine). That means high titer-low passage vaccines can generally elicit an immune system response in young animals who have a maternal antibody level that would normally prevent them from responding.

Nevertheless, it is still important to isolate young puppies as much as possible from other dogs and from potential sources of infection until they complete the parvo vaccination series at 16 weeks of age. Currently, recommendations are for a booster a year from the initial vaccine series and then revaccination every three years.

I was thinking it was strange, on another thread, to have so many immunized dogs get sick.

I figured if the mom dog was up to date on vaccinations & the puppies had their vaccinations in a timely manner, and were kept from going near other animals until a month after all vaccinations were completed, that they were safe.

I understand not wanting to over-vaccinate animals needlessly, but it's IMO it's irresponsible to not maintain vaccinations in your pets. The pets have no choice. It's not like they can take themselves to the vet, they require their human to do that for them. It's part of basic animal care, isn't it?

Some of the pups that have gotten it recently had not had all of there shots or might have gotten there shots to early.

Niko is 20 weeks and fully immunized but I am still very cautious about exposing him to others. My Elvis is only 2.8 lbs and Izzy is only 3 lbs. I had them immunized when I got them last fall but am concerned about how they'll do if immunized again. Niko and Izzy didn't feel well for quite a few days after. I've spoken to my vet and he agrees with checking their titers before any more vaccines.

:thumbup::thumbup:
This is the NeoPar I vaccinate my ladies with a week before they are bred, then I vaccinate the babies when they are 4 weeks old, then start my puppy shots at 8 weeks old. That NeoPar has wiped out a lot of parvo cases that bcome epidemic in kennels and whereever a bunch of dogs are housed together....it is a lifesaver, and I am forever grateful to the doc that developed it and gave me instructions on how to vaccinate my mommas and babies in order to avoid ever having parvo ravage my home and dogs again.

Great information. It is good to be extra cautious in the first months with new pups, as Parvo is really tough.