Catalyzes the phosphorylation of thiamine to thiamine pyrophosphate. Can also catalyze the phosphorylation of pyrithiamine to pyrithiamine pyrophosphate. ATP + thiamine = AMP + H(+) + thiamine diphosphate Cofactor biosynthesis; thiamine diphosphate biosynthesis; thiamine diphosphate from thiamine: step 1/1. Homodimer. Belongs to the thiamine pyrophosphokinase family.