Sales tax paid on a vacation home is not allowed as an itemized deduction for specified items on Schedule A (Form 1040) Itemized Deductions, Line 5.
Sales tax would not be deductible if the vacation home is an actual piece of real property. If the vacation home was a recreational vehicle, then you would be able to deduct the sales tax.
To see the specified items that would be allowed:
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.