It took some remarkable medical breakthroughs to end the days when children were subject to a variety of crippling diseases, and it may take some remarkable ignorance on the part of parents to bring them back.

You have to be of a certain age to remember what it was like when childhood diseases hovered in the air like fallout from a weapon of mass destruction. Parents lived in constant fear that a simple trip to a public pool could end with a crippling polio infection. Measles was so common you were expected to contract it at some point, but hopefully late enough in childhood (after age 5 was best) to be able to withstand its fury. It took some remarkable medical breakthroughs to end those days, and it may take some remarkable ignorance on the part of parents to bring them back. Dr. Andrew Wakefield is living proof that it is much easier to plant irrational fears in the hearts of the public than it is to erase them. His 1998 study, published in a British medical journal, found links between vaccines and autism in children. But later it was determined he had outright falsified the data concerning all 12 subjects of his study and that, in fact, there is no link (something subsequent studies have confirmed). And yet the fears and conspiracy theories persist, and years of improvements in public health are at stake. When the government announced in March of 1963 that it was approving two separate vaccines for measles, it was the No. 1 childhood disease in the nation. The New York Times reported about 4 million children were contracting the disease annually at that time, and while only about 400 of them died, many more suffered crippling complications, including "deafness" and "mental defects." This is the background we need in order to assess comments such as those by Steve Carrico, who sat with his wife in front of ABC television cameras recently, each of them cradling one of their 2-year-old twin daughters, and explained why they won't vaccinate their children against anything. "We told them no vaccinations right off the bat," he said, referring to what he told doctors concerning his girls when they were born. "We feel we're making these decisions on our own, and we'll take responsibility for them." Indeed, many states allow people to refuse immunizations for medical, religious or personal reasons. That pretty much covers just about any excuse. But while Carrico may be legally allowed to make such a decision, it's unclear how he would take responsibility for what might happen to many other people because of that choice. In California, where the Carricos live, 49 cases of measles have been confirmed so far this year, compared to four last year. In New York City, 25 cases have been confirmed in recent weeks, including 12 children. In Canada, an estimated 300 people or more have contracted the disease in an outbreak that has spread through a rural part of British Columbia. These numbers are tiny compared to, say, the number of deaths each year from influenza (the Centers for Disease Control and Prevention estimates between 3,000 and 49,000 people have died annually from the flu over the last three decades, depending on the severity of the constantly mutating disease). But when you consider that the World Health Organization reports 14 people die from measles every hour somewhere in the world, I can think of a lot of reasons to keep the relatively tiny number of U.S. cases from getting a foothold and growing. Tom Hudachko, public information officer for the Utah Department of Health, told me there are two reasons to be vaccinated. One is to protect yourself. The other is to, as health officials like to put it, "protect the herd." "Certain people can't be vaccinated for health reasons," he said. Among these are children under a year old. Their health is protected when enough people around them are immunized so the disease can't spread. April is National Autism Awareness Month. On a national level, autism affects 1 in 68 children. Confronting this problem and finding strategies for prevention will take real data. Conspiracy theories breed suspicions and get in the way, and they could unwittingly bring back the health fears of yesterday.%3Cimg%20src%3D%22http%3A//