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 change of capitalism (including creative destruction) is the subject of great contention by adherents of other systems of macroeconomic organization who see the end-result of obsolescence as the creation of a permanent underclass that has an unequal level of access to capital investment, educational resources that are not necessarily of their own making, while others seek to create an equal outcome for disproportionate labor or capital inputs that have not as yet been able to demonstrate a viable model that can compete against free-market economies on a near-term or long-term basis. Technical change A technical change is a term used in