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
Stargardt disease long-term prognosis for patients with Stargardt disease is widely variable and depends on the age of onset and genetic alleles. The majority of people will progress to legal blindness. Stargardt disease has no impact on general health and life expectancy is normal. Some patients, usually those with the late onset form, can maintain excellent visual acuities for extended periods, and are therefore able to perform tasks such as reading or driving. A 2017 prospective epidemiologic study which recruited 81 patients with STGD over 12 months reported an incidence of between 1 and 1.28 per 10 000 individuals. The median age