HEALTH & SCIENCE

Vaccine making inroads against hepatitis B

While heralded as a success story, physicians are urged to stay the current course and to expand the vaccine's use to others at risk.

By Susan J. Landers, AMNews staff. Aug. 5, 2002. Additional information

Washington -- The introduction of the hepatitis B vaccine 20 years ago marked the decline of that disease and its accompanying serious health consequences in the United States -- a major public health achievement, notes the Centers for Disease Control and Prevention.

Before 1982, an estimated 200,000 to 300,000 people in the United States were infected with hepatitis B, including 20,000 children.

Since then, an extensive campaign that saw the vaccination of about 40 million infants and children and 30 million adults has resulted in a decline in the number of those infected in this country to an estimated 79,000 in 2001. In addition, the disease has been virtually eliminated in the health profession because of high vaccination rates.

"It's been a wonderful vaccine and has saved millions of lives and will save millions more because of the risk posed by the disease for liver cancer and liver failure," said Deborah Wexler, MD, executive director and founder of the Immunization Action Coalition in St. Paul, Minn.

But despite its successful 20-year run, the vaccine still hasn't reached many of those at risk of infection by HBV, which is found in the blood and other body fluids of infected people. Contact with even a small amount of infected blood can cause infection.

Young adults and intravenous drug users are often missed in vaccination campaigns. A sweep through the nation's prisons could catch many of those carrying the virus. And by requiring student vaccinations, colleges could help with that group.

"On the order of magnitude of 5% to 6% of Americans are infected with hepatitis B," said William Schaffner, MD, professor and chair of the Preventive Medicine Dept. at Vanderbilt University School of Medicine, Nashville, Tenn.

The first dose of the three-dose hepatitis B series of shots is generally administered shortly after birth. Older adolescents and at-risk adults can start the series at any time.

Many physicians have expressed concern about patients not returning for shots two and three once the series has begun, but Dr. Schaffner encourages them to begin the series anyway. "One shot is better than none and two shots are better than one," he said.

The cost for adults, which is not generally covered by health insurance, also could be a deterrent to many young adults in their first jobs or for IV drug users who already live at society's edge. The shots are about $90 for the series, and the physician's fee would be in addition to that.

The cost is about that of "a pair of athletic shoes and a big night on the town," noted Dr. Shaffner, and is well worth the price.

A worldwide effort

Infection can result in serious consequences. While many of those with the disease are able to fight off the virus, about 10% remain chronically infected and become carriers. Each year approximately 5,000 Americans die of liver failure related to hepatitis B and another 1,500 die of liver cancer related to hepatitis B.

"Although it is unheralded in this regard, the hepatitis B vaccine is really our first anti-cancer vaccine," Dr. Schaffner said. "This is also our first vaccine against a sexually transmitted disease. So this is big time."

There is an international effort under way using hepatitis B vaccine to control and substantially reduce the occurrence of liver cancer around the world, said Dr. Schaffner, noting that liver cancer is one of the leading cancers in China and in parts of Africa.

Under the sponsorship of the World Health Organization, more than 100 countries are now immunizing their children routinely, he said.

Although the vaccine was first recommended for those at high risk for infection -- including intravenous drug users, men who have sex with men and those who have heterosexual relations with many partners -- it became apparent that many people were being missed.

In 1991, the CDC's Advisory Committee on Immunization Practices recommended universal childhood vaccination to prevent the infection of newborns from their mothers as well as the vaccination of high-risk adolescents and adults. Throughout the 1990s the recommendation was broadened and now includes all children through age 19.

The recommendations have been widely adopted and, from 1993 to 2000, the national coverage rate for hepatitis vaccine among children 19 to 35 months old increased from 16% to 90%, while the coverage rate for U.S. adolescents ages 13 to 15 increased from near zero to 67%.

The nation now has a cohort of vaccinated children to help ensure the defeat of the disease in time. But adults are still likely to remain unprotected.

"Our program from age 19 on up is much less successful, just as all adult immunization programs are less successful," Dr. Shaffner said. "Doctors are often not good at identifying who's at risk. Patients don't always tell doctors the whole story."

While the vaccine advisory committee recommends the vaccine for patients who have had more than one sexual partner in the last six months, Dr. Shaffner would broaden that to urge immunization for all patients who are sexually active and not monogamous.

The vaccine's wide acceptance rate for infants and children was not arrived at without some setbacks. The disease is "silent in infancy," noted Dr. Wexler, as it doesn't manifest any clinical symptoms at that time. So physicians and parents were somewhat reluctant to administer the vaccine, she said.

The vaccine was also thought by some to cause such serious diseases as multiple sclerosis, and its administration to newborns was halted while thimerosal was removed from it.

The vaccine is now viewed as safe. "It's an excellent vaccine. I have given thousands of doses, and I haven't seen an adverse event from it myself," Dr. Wexler said.

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Over the past two decades, hepatitis B immunization in the United States has been recommended as follows:

June 25, 1982 For groups known to be at high risk for hepatitis B virus
June 7, 1985 For heterosexual people with multiple sexual partners and travelers to areas where HBV infection is endemic
Feb. 9, 1990 For public safety workers who have contact with blood or blood-contaminated body fluids
Nov. 22, 1991 For all U.S. infants
Aug. 4, 1995 For all children age 11 and 12 who have not previously been vaccinated.
Jan. 22, 1999 For all children from birth until the age of 19

Source: Centers for Disease Control and Prevention

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Article, "Achievements in Public Health: Hepatitis B Vaccination -- United States , 1982-2002," Morbidity and Mortality Weekly Report, June 28 (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5125a3.htm)

Immunization Action Coalition (http://www.immunize.org/)

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Copyright 2002 American Medical Association. All rights reserved.