Hello and thanks for trusting me to help you and your pet today. I am a veterinarian with over 25 years experience and would be happy work with you.
It is not uncommon for a kitten to seem a little lethargic for a day or two after a vaccine is given, but that is not usually the case with the intranasal varieties of vaccine. If anything at all when using intranasals, there may be a slight nasal discharge or sneezing for a few days.
It is possible that her behavior has nothing to do with the vaccine at all and if so, unless it improves in the next day or so, I would have her examined by your veterinarian. Even vaccinated kittens can come down with viruses or other ailments. As long as she is still eating, drinking and eliminating normally, it would be OK to just monitor for the next 24 hours or so.
As far as re-vaccination, it would be best to follow the manufacturers instructions on that. In most cases, kittens are vaccinated every 3 weeks until they are up to or over 12 weeks, so in that case, I would repeat in 3 weeks.
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