Can anyone advise if there are any specific immunizations required/recommended when travelling to Greece from the US/Canada?

None. I would caution you to drink bottled water if and when you have doubts about water quality wherever you go. It's available everywhere.

Greece is not a 3rd world country. You are not likely to catch an exotic disease there. The water is perfectly safe to drink.

I've been to Greece a couple of times, never got a shot, always drank tap water. You'll be fine.

Yes, you can drink the water if you want too but if it doesn't taste right, like some of the brackish water on Santorini that comes from deep-water wells on the island, why would you want to? And on many of the islands the only source of water is from this sort of well or from rainwater that's caught and stored in a catchbasin attached to the house. After sitting for awhile it really doesn't taste very good, especially by the end of tourist season when the island's suppliers of water are running short. I prefer the bottled stuff.

ttt

I have personally seen and diagnosed Kala Azar in folks from the US visiting Greece.
Just like most countries, avoid farms with livestock.
www.cdc.gov as always.
M (MD, etc.)

Stick to the same brand of bottled water, as all have different components. While the tap water may be safe to drink, different communities purify the water using different chemicals, and the changes can lead to stomach upsets.

Thanks to all who replied.