When the number of hepatitis A cases hit peak levels in Southern Nevada in the late 1990s, health officials required all food workers to get immunization shots to prevent the virus that could cause liver damage and lead to death.
But after the number of cases dropped to historic lows in the 2000s, the immunization rule was eliminated.
Today, hepatitis A cases are now on the rise around the U.S. and in Southern Nevada, where health officials reported last week that an infected Las Vegas 7-Eleven clerk handled hot dogs and hot deli items and exposed an unknown number of customers to the virus.
When should immunization shots be mandated to fight disease?

