Varicella vaccine

The varicella-zoster virus (VZV) causes two distinct clinical diseases: varicella (chickenpox) and herpes tester (shingles). Heberden first differentiated the two diseases in 1767, when he called chickenpox varicella, a diminutive form of the Latin variola (smallpox). The derivation of the term chickenpox is less clear. Some state that it derives from the Old English word gican, which meant "itch" and is pronounced with a soft g. Most authorities, however, believe that the allusion is to the chickpea, pois chiche in French.(57) When sliced in half and laid on a pink-colored disc, the chickpea bears a remarkable resemblance to the characteristic erythematous vesicles seen in chickenpox.(48) Herpes comes from the Greek herpes, "to creep." The terms zoster and shingles derive from the respective creek and Latin terms zoster and cingulum, for the "girdle"-like dermatomal distribution of the rash. Weller and Stoddard(74) first isolated virus in tissue culture from vesicle fluid of chickenpox and tester in 1952. The viruses recovered were identical, and the name varicella zoster virus was given to the agent.