
From what I gather, the virus is easily caught and may as well come from the bitch as the dog. I found this article very informative:
http://www.2ndchance.info/herpesvirusdog.htmHaving said that, I've stopped using the vaccine as with my dogs, it didn't make a difference. I never used it for Malinois, and have never lost a puppy other than one we PTS after a efw days as it was so small and weak, and 2 that were stillborn in large litters. So have just lost 3 pups in total over the years in them. Then I mated a Papillon for the first time and in her first litter there were two stillborn pups, one that had died very recently, one had probably been dead a week or more. No live ones. So next time we used the vaccine. She had two stillborn pups again (so vaccine made no difference) and one live, then was spayed. The next papillon I used the vaccine on the first time, the second time I didn't bother. 3 live pups first time, 4 next time. However, as there is no harm in using it, you can always play safe!
I have had a bitch boostered at the same time as mating, ten live pups. I honestly can't remember if I ever had anyone else boostered when I've had newborn pups.