system
Given the following post, respond as if you're commenting on Reddit:
human
[SUPERMAN] When Kal was first launched to earth, wouldn't he be completely vulnerable to most of earth's diseases?
gpt
Most diseases are species specific or limited to one or two species.  As an alien, he's likely not vulnerable to any Earth based virus.  Plus while the sun didn't give him full powers until he was a teenager or grown in most continuities, it still may have done enough to protect him from diseases.