Varicella vaccine after the vaccine was recommended in the US, the CDC reported as much as a 90% drop in chickenpox cases, a varicella-related hospital admission decline of 71% and a 97% drop in chickenpox deaths among those under 20. Vaccines are less effective among high-risk patients, as well as being more dangerous because they contain attenuated live virus. In a study performed on children with an impaired immune system, 30% had lost the antibody after five years, and 8% had already caught wild chickenpox in that five-year period. Herpes zoster (shingles) most often occurs in the elderly and is only rarely
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