Time-displaced Germany and the disease question

What would happen if Germany and its colonies from 1914 were transported to 1649?

Germany could dominate militarily and industrially, but the disease warning is disputed and its application to the 1914 population is left unresolved.

The scenario sends Germany and its colonies from 1914 to 1649 with their institutions and industry intact. An initial prediction of catastrophic disease is challenged because many diseases would already be familiar to both populations. A broader warning concerns taking unvaccinated people from a world without smallpox into one where it circulates; its application to the 1914 population remains unresolved. Vaccination would change that general risk. Germany's industrial and military advantages are expected to be enormous if it survives the disease problem.