CHAPTER ONE: THE CHILDREN New Haven, Connecticut It was the most ordinary of family moments. the baby was just starting to talk, and Mom wanted a video of it. Lynne Avram handed the video camera to her husband, and he started shooting the playful interactions between Lynne and the babychubby little Paul, with his bright eyes beamingfocusing almost entirely on his son, instead of his wife, as new fathers are prone to do. To him, and to Lynne, too, the babyand every ordinary thing the baby didwas absolutely unprecedented. It was as if no child had ever before taken so majestic a first step, or burped so remarkably. Dad narrated as he filmed. "This is the day before Paul's very first birthday," he said, getting a close-up of gleeful Paul, tottering around barefoot in his red-striped shirt. "Can you say hi, Paul?" "Ha-ee! Ha-ee!" Paul responded, waving at the camera.

"Hi, sweetie!" said Lynne. "Hi-hi!" Paul grinned at Lynne, and his face was lit with love, easy to read, in that striking nonverbal way that toddlers have of telling the world how they feel. "Ha-ee, da-duh!" said Paul. "Can you say, 'Hi mama?' " Lynne asked. Paul gazed happily at his mother, and brushed at his nose. His nose was a little runny. It had been runny for several days. Lately, he was picking up every cold that came around.

"Pauly," said Lynne, "can you say ma-ma? Ma-ma?" "Da-duh!" "You think this is pretty funny, huh?" Lynne said, laughing. "Uh-uh!" said Paul, shaking his head emphatically. "Uh-uh!" What a unique child! What an extraordinary family moment! Truth be told, of course, it was all quite ordinary. In the years to come, though, Lynne and her husband would watch this video many times. It was a video of one of their last ordinary family moments. Paul's runny nose lingered for several days. Then he started to get better, but caught something else. Paul seemed to have a bad case of the common malady that parents call the day-care flucatching every germ in towneven though Paul stayed at home with Lynne.

Paul, in fact, still had his cold on the day he was due for his next- to-last round of immunizations, at fourteen months. He needed a measles-mumps-rubella shot, and a booster to protect him against a form of meningitis. Just before the appointment, Lynne called Paul's doctor and asked if it was safe to give vaccines to kids when they were sick. The doctor told her not to worryit happened all the time. If parents waited for perfect health in their toddlers, he said, the kids would never get all their shots. These days, he said, there were more shots than ever, and they were all important. Whole epidemics had been wiped out! But Lynne still felt uneasy. Jittery.

Couldn't shake it. She was a registered nurse at a prominent hospital near the Yale University campus, and it seemed to her that it went against medical common sense to provoke a powerful immune response in a child whose immune system was already battered by illness. But she told herself that her fear was just garden-variety parental paranoia. After all, she worked with some of the finest physicians in America, and she had a flint- hard faith in their expertise. As a nurse in one of the world's best coronary intensive care units, she regularly saw doctors snatch patients' lives back from the shadow of death. They worked miracles. So Paul got his shots, and everything was back to normal. Lynne and Paul went home and played.