Uncommon though they are, such events can have a profound effect on parents, stirring up persistent fears. Stories of kids coming down mysteriously with autism , diabetes or juvenile arthritis not long after receiving an inoculation abound, particularly on the Web. And with just a few clicks of the mouse, parents can find themselves at sites describing not only how dangerous vaccines are but also how the federal government is supposedly using immunization records to monitor civilian activity. Yet studies have repeatedly failed to find any connection between receiving vaccines and coming down with serious ailments such as autism or diabetes. The problem arises, Halsey says, when people assume that the vaccine was the culprit.
Vaccines are commonplace in developed countries, thanks mostly to government regulations.
In the U.S., immunization rates for most vaccines are more than 90 percent. The rate is high, explains Michael A. Gerber of the NIH's National Institute of Allergy and Infectious Diseases , because states require that children receive the standard shots before they can enter day care or public schools. In the case of inoculation against chicken pox, however, protection is much lower. For much the same reasons, the vaccination rate against hepatitis B is also somewhat low, at 87 percent. Although researchers like Gerber encourage parents to inoculate their children against chicken pox and hepatitis B, many are resisting.