I had MMR and tetnus vaccination 3 weeks ago. Is it safe to have Botox now?

Thank you for your excellent question.  You should be just fine to proceed with your Botox treatment.  Please be sure to see an expert for an in-person consultation to fully discuss your concerns and your goals and expectations in order to determine the best treatment plan.  Hope this helps and best wishes! 

Kcaff,
This is actually a good question. The answer to your question is Botox can be administered safely with any vaccine.
As an aside, it is interesting to note that there have been no studies performed on administering the flu vaccine simultaneously with any other vaccine. This fact is listed within the package insert section 7.1 where considerations are listed.  Because of this, it is reasonable to elect to have the flu shot administered separate from other vaccines.