Why didn't disease carried by the Viking Explorers of the New World not cause as much devastation among the native population as that caused by the Post-Columbian Explorers of the New World?

by sherbold
Dinocrocodile

Not to discourage any further answers but you'll probably enjoy this older post:

If the Vikings visited North America before 1492, was there any evidence that any population was wiped out (partially or otherwise) by small pox? by /u/Reedstilt