Important, flu or food poisening?

I think that it is mild food poisoning. If his colleague has it as well and he doesn't have a fever he is probably going to be fine in the next 24 hours as the food poisoning pes from his system. Your baby will be fine. Just keep feeding and give baby all of your antibodies. The vaccination will only trigger an immune response so even if he does have the flu it wouldn't be intensified because of the vaccine.