The chickenpox (varicella) vaccine was approved for use in the United States in 1995 and quickly became part of the universal immunization schedule for children. Before the vaccine was introduced, 4 million persons in the U.S., most of them children, developed chickenpox each year. About 12,000 of these patients were hospitalized and about 145 of them died each year. Most of the deaths were in healthy individuals. Since 1995, the incidence of chickenpox in the United States has declined by as much as 90%. In a study published in February in the New England Journal of Medicine, researchers from the CDC looked for the first time at all chickenpox related deaths in the U.S. They found that the death rate dropped sharply starting in 1998, with a 66% reduction in deaths due to chickenpox. The greatest reduction (92%) was in children ages 1 to 4 years old.
Despite its success, major questions about the vaccine remain. In particular, immunity decreases over time and adults who were vaccinated as children may become susceptible to the disease (which does not happen when a child gets chickenpox naturally). Adults may need booster shots. Some experts believe that zoster (shingles) may increase due to the vaccine; other experts believe that it will decrease because of the vaccine. Only time will tell. There is still the issue of whether the vaccine was necessary at all. While some children and adults do die or suffer complications from chickenpox, these events are rare and the risk is low. Some have felt that the varicella vaccine was not truly necessary in the first place. Whatever the case, the vaccine is very effective at preventing chickenpox and its complications, including death.
