It takes the intranasal vaccine up to 10 days to become fully effective. As well, it only covers a small percentage of the viruses and bacteria that actually cause "kennel cough" (well over 200 strains). Kennel cough is literally any upper respiratory infection/disease.
Kennel cough normally resolves on it's own within a week or so. And as the cause is unknown unless cultured, antibiotics are iffy because they will have no effect on viral infections. If you are concerned, the dog becomes listless, lethargic, doesn't want to eat or drink, or you feel the cough becomes severe, then see your vet.
~Emergency Vet Tech
Berlin vom Spartanville 1/13/13
2008 - 7/23/12
"Take this trouble from me: Make sure my shepherd dog remains a working dog, for I have struggled all my life long for that aim." Max Von Stephanitz