Vaccinations are for big people too: adults should consider asking their doctors about hepatitis B and other ailments.

Vaccinations aren't just kid stuff. Depending on age and lifestyle, adults should consider asking their doctors about vaccines that can protect against influenza, pneumonia, hepatitis B, and other ailments.

Don't rely on your physician to bring up the topic, public health officials say. Adult vaccinations are a neglected topic because other issues take precedence during a physical exam.

What is your best bet? "Ask your doctor what vaccination you need and when, and if it needs to be repeated," says Jacqelyn Admire, spokesperson for the American Academy of Family Physicians.

Experts disagree slightly about which vaccines adults need, but they concur that individual risk factors are important criteria in the decision.

Vaccines usually contain a killed or weakened form of the organism they are designed to counteract. When injected, these organisms spur the body to develop antibodies against the invaders, creating an immunity.

Probably the most overlooked vaccine for adults is the one against tetanus and diphtheria, says Robert Alan Winters, M.D., who is an infectious disease specialist at Santa Monica Hospital Medical Center in California. A booster is recommended every decade, although there is some controversy over whether the 10-year interval is too frequent.

Tetanus is caused by infection of a wound with a bacterium often found in soil and manure. Diphtheria, a problem mainly in developing countries, is also a bacterial illness. Sadly, most people ignore the recommendation to update immunizations against tetanus and diphtheria until they have a painful encounter with a rusty nail. Admire suggests that people remember their tetanus-diphtheria booster on their "zero birthdays": 30, 40, and so on.

Hepatitis B, an inflammation of the liver, was once considered a disease of homosexual men, intravenous drug users and health-care workers. These days many other populations are at risk, including sexually active heterosexuals who have multiple partners and those with a history of sexually transmitted diseases. Over the next several years the hepatitis B vaccine will become "part of the standard package," Winters says.

The hepatitis B vaccine is not cheap. The three-dose regimen, given over a six-month period, costs about $150. A blood test can determine if you already have antibodies and do not need the vaccine.

If you were born after 1957, you should consider being reimmunized against measles, most experts advise. From about 1963 to 1967 the measles vaccine was ineffective, says Donald M. Poretz, M.D., a spokesperson for the National Foundation for Infectious Diseases and an infectious disease specialist in Fairfax, Virginia. (Because the first measles shot is given at age 15 months and the second shot at 4 and 6 years of age, those people who had their second shot between 1963 and 1967 are not adequately covered.)

"If there is any doubt, get another," says Dr. Poretz. Of course, you can get a blood test to determine if you already have antibodies to measles.

Government guidelines suggest the influenza vaccine for people over 65 and those with chronic medical conditions, such as heart, lung, or immune system problems. But this year some experts are recommending that other groups consider the flu shots as well, because the season is expected to be particularly bad.

Among the elderly, the pneumococcal vaccine is often neglected. The vaccine protects against 23 of the most prevalent types of pneumococcal pneumonia, says Kenneth Keen, a spokesperson for Merck and Company, which manufactures a pneumonia vaccine. It is usually a onetime injection. "People can get flu and pneumonia injections during the same office visit," he adds.

Some adults might need protection against mumps. "Mumps is no longer just a disease of childhood," says Kay Golan, spokesperson for the Centers for Disease Control and Prevention. "Many cases now occur in teens and young adults"--people who did not come down with mumps as children and who may not have been vaccinated. Generally, she adds, people born before 1957 are immune because they have had mumps.

Adults not vaccinated against rubella (German measles) as children should consider getting that vaccine, Golan says. The advice is especially critical for women of childbearing age.

Chicken pox, a viral disease, is usually mild in children, but can be severe in adults. A vaccine has recently been approved by the U.S. Food and Drug Administration.

Travelers abroad should be especially careful to keep their vaccinations for diphtheria, pneumonia, and hepatitis B current. Diphtheria and hepatitis B are prevalent in many foreign countries. And there has been an increase in antibiotic-resistant strains of pneumonia abroad.