STD Awareness: Hepatitis B Virus and the HBV Vaccine

Hepatitis B virions are pictured in this transmission electron micrograph. Image: National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention.

July 28 is World Hepatitis Day. This month’s installment of our STD Awareness series will shine the spotlight on the hepatitis B virus (HBV), which can be transmitted sexually as well as nonsexually.

Hepatitis viruses infect the liver. Hepatitis A, B, and C can be transmitted sexually, and hepatitis B is the most likely to be spread this way. HBV is present in vaginal fluids, semen, and blood. It is highly contagious and can be transmitted by most sexual activities, such as vaginal or anal intercourse, as well as oral sex. HBV can also be spread by exposure to infected blood, and an HBV-infected mother can pass the virus onto her infant during birth.

To protect yourself from HBV, make sure to use latex barriers, such as condoms and dental dams, if you are sexually active. Also, don’t use unsterilized needles; don’t share hygiene items that could have infected blood on them, such as razors and toothbrushes; and consider being vaccinated against hepatitis B.

About half of all people infected with HBV don’t show signs or symptoms. Those who do develop symptoms usually do so within six weeks to six months of infection, and they might experience fatigue, hives, fever, abdominal pain or tenderness, joint pain, loss of appetite, nausea, or vomiting. Later symptoms might include jaundice, pale stools, dark urine, and intense abdominal pain.

At least 90 percent of sufferers make full recoveries with an average 12-week recovery time. It is important to note, however, that an estimated 6 to 10 percent of adolescents and adults with HBV become chronic carriers – the virus enters a latent state in the host’s cells, which means that a carrier will remain contagious even after his or her own symptoms have disappeared. They are also at increased risk for liver cancer and cirrhosis, both of which can be fatal. Chronic HBV infection cannot be cured, but it can be managed with medications such as entecavir, which slows viral replication.

The vaccine, however, offers an important avenue of treatment. Even after exposure to HBV, it is highly effective in preventing chronic infection. If you think you have been exposed, you can reduce risk of chronic infection by getting vaccinated within 14 days. In addition to the vaccine, other methods of post-exposure prophylaxis might be appropriate. Talk to a health care provider about your concerns.

Engerix-B is one of several hepatitis B vaccines available. There are formulations for both pediatric/adolescent patients and adult patients.

The hepatitis B vaccine has made amazing progress in the control of the virus; it is possible that with widespread vaccination, HBV will someday go the way of smallpox and be eliminated completely. It is similar to the HPV vaccine in that one of the virus’ components, in this case a surface antigen, is produced by a genetically modified yeast, Saccharomyces cerevisiae. The vaccine is created by purifying the yeast-produced antigen and suspending it in a sterile liquid along with an aluminum-containing adjuvant, sodium chloride, and phosphate buffers. Because the vaccine does not include any viral DNA, recipients won’t become infected with HBV by the inoculation.

The first vaccine for HBV was released in 1981. At that time, public health officials targeted the vaccine toward high-risk groups: sexual partners of people with HBV, health-care workers, intravenous drug users, prisoners, and people who get tattoos using improperly sterilized equipment. Unfortunately, this strategy had no impact on the infection rate. After a decade of implementing this ineffective strategy, health officials introduced a new plan, which was to recommend the vaccine for all babies. Before the hepatitis B vaccine was introduced, 16,000 people under the age of 10 were infected annually by nonsexual contact such as sharing toothbrushes. This young population is at a greater risk for developing chronic infections, which can lead to cirrhosis or liver cancer. Unfortunately, because the vaccine was formerly targeted exclusively at high-risk adult populations, HBV was stigmatized as a disease that only affected marginalized groups. For this reason, people resisted vaccinating their infants.

Intensifying the public’s resistance to the vaccine, some media sources started to associate – incorrectly – the vaccine with multiple sclerosis (MS) and sudden infant death syndrome (SIDS). Large epidemiological studies of tens of thousands of people, however, failed to find a correlation between HBV vaccination and MS. SIDS was also not found to be linked to the vaccine, and its rate decreased thanks to a successful “Back to Sleep” campaign encouraging parents not to let their infants fall asleep on their stomachs.

Some people are concerned that vaccines present too much of a challenge to an infant’s immune system. However, babies born to mothers with HBV are exposed to the virus during delivery (one teaspoon of blood can contain 5 billion virus particles), and without the vaccine, their risk for infection is almost 100 percent. Even though the vaccine is administered after exposure to the virus during birth, it provides almost total protection. In addition, the vaccine presents a much smaller immune challenge than the birthing process. After the vaccine was first recommended for infants in 1991, HBV has been all but eliminated in the U.S. pediatric population.

Hepatitis B is diagnosed with a blood test. You can obtain a diagnosis or a preventive vaccine* at a Planned Parenthood health center, as well as other clinics, health departments, and private health-care providers. You can find more information about hepatitis B and the HBV vaccine at Planned Parenthood’s website, the CDC’s website, or the Hepatitis B Foundation.

Click here to check out other installments of our monthly STD Awareness series!

* Edit, April 18, 2017: Planned Parenthood Arizona no longer offers hepatitis B vaccinations. This vaccination can be obtained at other health centers, public health clinics, and health-care providers.