A number of hepatitis B vaccines are available. They have typically been given in a series of three immunizations at zero, one and six months, but some can also be given in an accelerated four-dose schedule. Another is given in two doses in adolescents ages 11 to 15. These vaccines provide more than 90 percent protection for both adults and children, and they generally protect against HBV for at least 23 years. You can't get hepatitis B from the vaccine.
Almost anyone can receive the vaccine, including infants, older adults and those with compromised immune systems. Infants often receive the vaccine in the first year of life — typically at 2, 4 and 9 months of age.
Side effects tend to be mild and may include weakness, fatigue, headache, nausea, and soreness or swelling at the injection site. Although concerns have been raised that the HBV vaccine may increase the risk of autoimmune disease, studies have found no connection.
Although vaccination is the best way to protect yourself and others from hepatitis B, the measures listed below also can help guard against HBV infection or help manage HBV if you have it.
If you're not infected with HBV
The following measures can help keep you from becoming infected with HBV:

• Educate yourself and others. Make sure you understand what HBV is and how the virus is transmitted.

• Know the HBV status of any sexual partner. Don't engage in unprotected sex unless you're absolutely certain your partner isn't infected with HBV, HIV or any other sexually transmitted disease.

• Use a new latex or polyurethane condom every time you have sex. If you don't know the health status of your partner, use a new latex condom every time you have anal or vaginal sex. If you're allergic to latex, use a plastic (polyurethane) condom. Avoid lambskin condoms because they don't protect you from sexually transmitted viruses. If you don't have a male condom, use a female condom. Use only water-based lubricants, not petroleum jelly, cold cream or oils. Oil-based lubricants can weaken condoms and cause them to break. During oral sex use a condom, dental dam (a piece of medical-grade latex) or plastic wrap. Remember that although condoms can reduce your risk of contracting HBV, they don't eliminate the risk entirely. Condoms can break or develop small tears, and people don't always use them properly.

• Use a sterile needle. If you use a needle to inject illicit drugs, make sure it's sterile, and don't share it. Take advantage of needle exchange programs in your community and consider seeking help for your drug use.

• Talk to your doctor if you're traveling internationally. If you're planning an extended trip to a region where hepatitis B is endemic, ask your doctor about the hepatitis B vaccine well in advance. It's usually given in a series of three injections over a six-month period.

• Be cautious about blood products in certain countries. Although the blood supply is now well screened in the United States, this isn't always the case in other countries. If an emergency requires that you receive blood or blood products in another country, get tested for HBV as soon as you return home.

• If you're pregnant, get tested. Knowing whether you're infected with HBV can allow you and your doctor to take steps to protect your child.

If you're infected with HBV

If you've received a diagnosis of HBV, the following guidelines can help protect others:

• Practice safe sex. The only foolproof way to protect your sexual partner or partners from HBV infection is to avoid practices that expose them to blood, saliva, semen and vaginal secretions. Barring that, carefully follow guidelines for safe sex, including using a new latex condom every time you have vaginal or anal sex and using a dental dam, condom or piece of plastic wrap during oral sex. If you use sexual devices, don't share them.

• Tell your sexual partner(s) you have HBV. Let anyone with whom you've had sex know that you have HBV. Your partners need to be tested and receive medical care if they have the virus. They also need to know their HBV status so that they don't infect others.

• Don't share needles or syringes. If you use IV drugs, never share your needles and syringes with anyone.

• Don't donate blood or organs. Donating infected blood or organs spreads the virus.

• Don't share razor blades or toothbrushes. These items may carry traces of infected blood. Some experts also suggest not sharing your comb, hairbrush and nail clippers.

• If you're pregnant, tell your doctor you have HBV. That way, your baby can be treated as soon as he or she is born.

Prevention of Hepatitis C

Because no effective vaccine for hepatitis C exists, the only way to protect yourself is to avoid becoming infected. That means taking the following precautions:

• Avoid illegal drug use. Don't share needles or other drug paraphernalia. Contaminated drug paraphernalia is responsible for more than half of all new hepatitis C cases. Avoid nasal use of cocaine. Blood on shared straws also can transmit the virus.

• Avoid body piercing and tattooing. If you do undergo piercing or tattooing, be absolutely certain the equipment is sterile.

• Avoid risky sexual behavior. Don't engage in unprotected sex with multiple partners or with one partner whose health status is uncertain. Sexual transmission between monogamous couples may occur, but the risk is low.