Was about to book two nights at Iguazu falls, but now not sure if I need yellow fever vaccine or not. It's too late to get it since I need to get it at least ten days before heading there. My other two destinations (Rio and Buenos Aires) don't require it. But from reading other posts not sure if I need it or not.

I've seen some people post there is 0 chance of getting it, but other say not to even take a risk. Also saw someone mention that yellow fever vaccine is required to cross Brazil border.

Am I just overthinking this? Or would I be better off leaving Iguazu falls for another time?