exposure to infectious diseases like chicken pox does not mean that you can spread it to others. you would actually need to have chicken pox yourself in order to do that. chicken pox re-exposure can cause you to get shingles but that would be a different question. your co-workers in food service will not be at risk.
if my grandkids got chickenpox and i already had it can i go to work and not infect people i work in food service