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
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