Varicella vaccine from a child with natural varicella, introduced into human embryonic lung cell cultures, adapted to and propagated in embryonic guinea pig cell cultures, and finally propagated in human diploid cell cultures. Japan was among the first countries to vaccinate for chickenpox. The vaccine was first licensed in the United States in 1995. Routine vaccination against varicella zoster virus is also performed in the United States, and the incidence of chickenpox has been dramatically reduced there (from 4 million cases per year in the pre-vaccine era to approximately 400,000 cases per year as of 2005). In Europe most countries do not
Technical diving diving" has been credited to Michael Menduno, who was editor of the (now defunct) diving magazine "aquaCorps Journal". The concept and term, "technical diving", are both relatively recent advents, although divers have been engaging in what is now commonly referred to as technical diving for decades. The term "technical diving" can be traced back to the cover story of the first issue of "AquaCorps" magazine, in early 1990, titled "call it "High-Tech" Diving" by Bill Hamilton, describing the current state of recreational diving beyond the generally accepted limits, such as, deep, decompression and mixed gas diving. By mid 1991, the