Government health officials have conceded that childhood vaccines worsened a rare, underlying disorder that ultimately led to autism-like symptoms in a Georgia girl, and that she should be paid from a federal vaccine-injury fund. Thousands of families are seeking compensation for disabilities they attribute to vaccines and a preservative. Medical and legal experts say the narrow wording and circumstances probably make the case an exception -- not a precedent for thousands of other pending claims. However, parents and advocates for autistic children see the case as a victory that may help certain others. Although the science on this is very limited, the girl's disorder may be more common in children with autism than in healthy ones. It's a beginning," said Kevin Conway, a Boston, Massachusetts, lawyer representing more than 1,200 families with vaccine injury claims. "Each case is going to have to be proved on its individual merits. But it shows to me that the government has conceded that it's biologically plausible for a vaccine to cause these injuries. They've never done it before." Nearly 5,000 families are seeking compensation for autism or other developmental disabilities they say are caused by vaccines and a mercury-based preservative, thimerosal. It once was commonly used to prevent bacterial contamination but since 2001 has been used only in certain flu shots. Some cases contend that the cumulative effect of many shots given at once may have caused injuries. The cases are before a special "vaccine court" that doles out cash from a fund Congress set up to pay people injured by vaccines and to protect makers from damages as a way to help ensure an adequate vaccine supply.