[Edit: Got injected so wife won't get sick.] Wife got sick. Can't be from him as he's the injected. Therefore, everyone must be injected else his wife will continue to get sick.

They're making fun of the vaccine that she got pregnant because someone else fucked her even though he got the vasectomy. It's quite simple and quite clever all at once and funny as hell.

I guess honey you got me pregnant since the hung guy next door didn't also get a vasectomy since we all know it works like that.