Varicella vaccine seen in children. The incidence of herpes zoster in vaccinated adults is 0.9/1000 person-years, and is 0.33/1000 person-years in vaccinated children; this is lower than the overall incidence of 3.2–4.2/1000 person-years. Adult shingles cases may increase after introduction of varicella vaccine, but evidence is unclear. While research using computer models has tended to support the hypothesis that vaccination programs would increase incidence of zoster in the short term, the evidence from epidemiological studies is mixed, and increases observed in zoster incidence in some studies may not be related to vaccination programs, as the incidence increases prior to the varicella vaccine
Short-term memory becomes even more difficult. However, capacity of STM can be affected by the following: Influence of long-term memory, Reading aloud, Pronunciation time and Individual differences. Diseases that cause neurodegeneration, such as Alzheimer's disease, can also be a factor in a person's short-term and eventually long-term memory. Damage to certain sections of the brain due to this disease causes a shrinkage in the cerebral cortex which disables the ability to think and recall memories. Memory loss is a natural process in aging. One study investigated whether or not there were deficits in short-term memory in older adults. This was a previous