"Yeeeeeees?" Oh no. Ohhhh he hates where this conversation is going.

"Please, please tell me you don't mean to imply you came from a world without diseases." He looks over Erin's shoulder at the crowd of people, several of whom embraced her in happy greeting before, or after, or while eating the townspeople's food or shaking their hands or just standing in extremely close proximity.

If all these newcomers are immunocompromised, then...then...

"We only just managed to reinvent penicillin," he says blankly. "We don't have any anti-virals. Oh. This is going to suck."