Beginning Aug. 1, the vaccination is necessary for individuals born since Sept. 2, 1992 and older than 2, who will attend public or private school or child care this fall. Failure to comply may result in denied entry.

An infectious and potentially fatal liver disease, hepatitis A is occurring with greater frequency in Texas than the national average, according to the Centers for Disease Control and Prevention, which ordered the requirement.

Dr. Fernando Guerra, Clinical Professor of Pediatrics at the University of Texas Health Science Center in San Antonio, said the averages in area counties have been on a steady decline during the last few years, but the historical average for hepatitis A cases in these counties is higher than the national average. The historic rate is 20 infected people out of 100,000. Guerra said Potter, Randall and Moore counties do not necessarily have more cases than other Texas counties. However, the three counties only recently have been added to the nationwide list of counties mandated to vaccinate children.

Guerra does not expect an increase in cases in the Panhandle, but he hopes to see fewer if people attend to the vaccination mandate.

"While it is a lot more work - a lot of people will need their vaccinations last minute - it will give us the opportunity to hopefully eliminate the virus," he said.

One problem besides the recurring cases of hepatitis A, Guerra said, is legislation undermining the vaccination requirements. The Texas Legislature passed legislation in this year's session that would allow parents to opt their children out of receiving the vaccination, regarding it as invasive or unethical, Guerra said.

"Now we have to deal with the consequences of this," he said. "And try to understand this, for example, how many kids would be at risk because of others not being immunized?"