The idea is to protect the children from themselves in later years. Hepatitis B is regarded as a so-called lifestyle disease, a blood-borne virus that, like HIV--the virus that causes AIDS--is transmitted predominantly through unprotected sex and intravenous drug use.
"We want to get to them before they begin to engage in sex or drugs," says Gerrit Bakker, the hepatitis B immunization coordinator for the Colorado Department of Public Health and Environment.
However, Bakker notes that unlike HIV infections, which can be traced almost entirely to at-risk behavior, the cause of as much as 35 percent of hepatitis B infections cannot be identified. Hepatitis B is more easily transmitted by contact with the blood of an infected person than is HIV, raising the possibility of exposure through other activities such as sports.
Following on the heels of recommendations by the Centers for Disease Control in Atlanta and the U.S. Public Health Service, the state health board altered the Colorado School Immunization law last April to require the immunizations. Colorado is now one of sixteen states requiring the immunization; eight others have laws, or amendments to current laws, pending.
School enrollment has traditionally been the chief means to enforce immunization requirements ever since a vaccine for polio, which is caused by the poliomyelitis virus, was developed in the 1950s.
The current push doesn't have the immediacy of the polio crusade, because the harmful effects of hepatitis B infections on the liver may not manifest themselves for a decade or more. However, the earlier in life the infection, experts say, the greater the chance of liver failure resulting in death or the need for a liver transplant.
Colorado has been vaccinating newborn infants for hepatitis B since 1991. The goal of this new effort is to catch up with children born before that time.
The vaccination requirement of seventh-graders is also part of a bigger effort to get adolescents in to see a doctor for counseling about the risks associated with puberty, including unsafe sexual practices, as well as a required second vaccination for measles, mumps and rubella, say health officials.
After 1997, the hep B program will be staggered to catch children in other grades. For instance, in 1998, children in kindergarten and first grade, as well as those in seventh and eighth grade, will be required to have proof of the immunization to enroll. Each year, another grade will be added so that by the year 2003, all schoolchildren in Colorado will have been inoculated.
While that might not eliminate hepatitis B in the general population, it will have a "huge impact" on this and succeeding generations of schoolchildren, Bakker says. Children currently in grades seven and above will miss out on the program.
"You can only do so much," he says. "It is a burden on the schools to enforce and also a financial burden."
It is too early to tell, Bakker says, but as many as 50 percent of children will be eligible for free vaccinations through a federal program that is paid for by taxpayers. Those eligible for free vaccinations include the uninsured, those on Medicaid, and Native American and Alaskan native children.
"The costs will be significant," Bakker says. "But the costs of liver transplants and liver disease are also tremendous."
Various school systems have already begun notifying Colorado parents of the new requirement. Some, like Denver Public Schools, in a joint program with the Denver health department, have already been administering the vaccinations, which must be given in three doses, in the schools.
In the past, new vaccinations, often using dead or weakened strains of a virus to jumpstart the body's immune system, have carried health risks with them. The new requirement has raised concern among parents, Bakker concedes.
However, he says, the hepatitis B vaccination has been in use since 1985. "It is probably the most extensively researched vaccination ever and is completely safe," says Bakker. "Sometimes people are uncomfortable with being required to do something. But this undertaking is in everybody's best interests."
Lost in the questions about the new program is a remarkable medical-science advance. The vaccination is the first ever developed to prevent a form of cancer, says Bakker. "Hepatitis B is second only to tobacco in causing cancer," he adds.