- Hepatitis A and B Vaccinations Center
- Hepatitis Pictures Slideshow: What Puts You at Risk
- Digestive Disease Myths
- Hepatitis Slideshow Pictures
What is hepatitis?
The term 'hepatitis' means inflammation of the liver. Hepatitis can be caused by viruses, other infectious agents, alcohol, and other chemicals. The two viruses that most commonly infect the liver are the hepatitis A virus and the hepatitis B virus. Although their names are similar, these viruses are not related. They differ in the way they are transmitted from person to person and their ability to cause chronic infection.
Hepatitis A vaccine
Hepatitis A is caused by a virus which is spread predominately through the fecal-oral route when small amounts of infected fecal matter are inadvertently ingested. Infected individuals shed large amounts of the virus in their stool, starting about two weeks before symptoms present, and continue shedding the virus in their stool for one to three months.
- Close contact with an infected person increases the chances of contracting the virus.
- Children are particularly contagious because they have lower standards of hygiene and may not appear sick.
- The hepatitis A virus also may be spread by ingestion of food or water that is contaminated by infected individuals.
- Much less commonly, contaminated needles or blood may spread hepatitis A.
Some patients with hepatitis A infection have no symptoms, and these asymptomatic infections are more common in children.
Most adults experience symptoms including:
Hepatitis A does not cause chronic or persistent infection of the liver. Once a person has recovered from hepatitis A, he or she is immune to reinfection with hepatitis A for life. This is true because effective antibodies are developed against the hepatitis A virus. After infection with hepatitis A, these antibodies provide life-long protection against the virus. The ability of the body to make protective antibodies after infection with hepatitis A led researchers to develop vaccines against the disease.
Hepatitis A vaccine is made of killed hepatitis A viruses and causes the body's immune system to produce antibodies against the hepatitis A virus. In most vaccine recipients, antibodies start to develop immediately after the first dose but do not reach protective levels for 2 to 4 weeks. A second dose of the vaccine is recommended at least six months after the first dose to provide prolonged protection.
Two hepatitis A vaccines are currently available in the United States; these vaccines arehepatitis a vaccine injection (Havrix and Vaqta). The vaccine is given as an injection into the deltoid muscle of the arm. Both Havrix and Vaqta provide high level protection against hepatitis A. There is also a combination vaccine called hepatitis-b-hepatitis-a-vaccine injection (Twinrix) that protects against both hepatitis A and hepatitis B. The dosing schedule for Twinrix is different from the other hepatitis A vaccines and requires three doses over six months.
In the United States, hepatitis A vaccination is recommended for all children at one year of age. Vaccination also is recommended for individuals in high-risk settings. Examples include:
- travelers to developing countries,
- men who have sex with men,
- users of illicit drugs,
- persons needing frequent blood products, and
- people who have chronic liver disease.
Side effects of the hepatitis A vaccine usually are mild. Soreness at the site of injection is common. Less commonly, recipients may complain of headache or fatigue. Serious allergic reactions are possible, but are rare.
A second option for protecting people against hepatitis A is to administer antibodies that are already programmed to attack the virus. When people donate blood, the part of the blood carrying antibodies (the 'immune globulin' fraction) can be separated. Because some blood donors are likely to have antibodies against the hepatitis A virus, pooled immune globulin from many donors is likely to contain antibodies against hepatitis A. This immune globulin can be injected into a person at risk for hepatitis A and will provide immediate but temporary protection against infection. Protection with immune globulin lasts two to four months depending on the dose. Immune globulin is used when immediate protection against hepatitis A is required. An example would be someone who is leaving immediately to travel to rural areas of a developing country. Such a traveler would also receive hepatitis A vaccine but would not have time to develop antibodies before departure. Immune globulin sometimes is in short supply and should be used only when necessary.
- If an unvaccinated person is exposed to hepatitis A, he or she should be given the vaccine or immune globulin as soon as possible.
- Vaccine is used for exposed persons aged one to 40 years.
- Immune globulin currently is recommended for exposed persons over the age of 40 years.
These measures will reduce the risk that the exposed person will contract hepatitis A by 85% to 90% if given within two weeks of exposure.
Quick GuideHepatitis C, Hep B, Hep A: Symptoms, Causes, Treatment
Hepatitis B vaccine
Hepatitis B was previously referred to as "serum hepatitis" because it usually is spread by the transfer of infected blood or serum (for example, through needle sticks, blood transfusions, hemodialysis, and childbirth). Hepatitis B also is spread through sexual intercourse and may be passed from mother to child. Inadvertent exposure to infected blood or body fluids may occur during tattooing, body piercing, or when sharing razors or toothbrushes with an infected person. Persons infected with hepatitis B may be asymptomatic or may develop fatigue, jaundice, and weight loss. Rarely - though more commonly than with hepatitis A - acute infection with hepatitis B can cause liver failure and death.
Most infected adults are able to clear the hepatitis B virus from their body and become immune to further infections with hepatitis B. However, some people are not able to clear the hepatitis B virus and it progresses to chronic (persistent) infection and inflammation of the liver. Most infants infected at birth and 25% to 50% of infected children aged 1–5 years have chronic persistent infection.
Chronic infection may be mild or may damage the liver. The majority of individuals with chronic hepatitis B who clear the virus and are "cured" still have detectable virus in the liver. However, the importance of this fact is unclear since there is no evidence of consequences to the presence of the virus except that it can be reactivated with immunosuppression. Individuals with hepatitis B virus only in the liver are not infectious. Some people with chronic hepatitis B infection have their lives shortened by complications of liver disease, cirrhosis, or liver cancer.
Vaccination has reduced the number of new cases of hepatitis B by more than 75% in the United States. The hepatitis B vaccine contains a protein (antigen) that stimulates the body to make protective antibodies. Examples of hepatitis B vaccines available in the United States include hepatitis B vaccine-injection (Engerix-B and Recombivax-HB). Three doses (given at 0, 1, and 6 months) are necessary to assure protection.
There are also combination vaccines on the market that provide protection against hepatitis B and other diseases. For example:
- hepatitis-b-hepatitis-a-vaccine injection (Twinrix), which provides protection against both hepatitis A and hepatitis B;
- Haemophilus B/hepatitis B vaccine - injection (Comvax) provides protection against hepatitis B and Haemophilus influenzae type b (a cause of meningitis); and
- Pediarix provides protection against hepatitis B, tetanus, pertussis and polio.
Hepatitis B vaccines are effective and safe. Most vaccinated individuals develop protective antibodies when they get the vaccine and are protected from infection with hepatitis B. Among individuals at high risk for infection with hepatitis B include:
- health care workers,
- intimate and household contacts of patients with chronic hepatitis B infection,
- public safety workers who may be exposed to blood products,
- men who have sex with men,
- individuals with multiple sexual partners,
- dialysis patients,
- injection drug users,
- persons with chronic liver disease,
- residents and staff in institutions that care for persons with developmental disabilities,
- persons infected with human immunodeficiency virus (HIV), and
- persons who require repeated transfusions or blood products.
Centers that serve high-risk individuals are encouraged to provide the vaccine to their clients. Such centers include:
- dialysis units,
- drug treatment facilities,
- sexually transmitted diseases clinics and correctional facilities.
A blood test for hepatitis B antibodies is recommended after vaccination to ensure that antibodies have been produced. For the few who do not form antibodies, revaccination may improve the response, especially in infants. However, a small proportion of individuals will never respond to hepatitis B vaccination. Side effects from the vaccine usually are mild, primarily soreness at the site of injection. The risk of serious allergic reactions (anaphylaxis) is less than one per million doses.
In the United States, hepatitis B vaccination is recommended for all infants at birth. Older children and adolescents should receive the vaccine if they did not receive it at birth. Adults in high risk situations also are advised to receive hepatitis B vaccine.
Some countries have a high prevalence of hepatitis B in their population. Travelers who visit these countries for a prolonged period of time (usually 6 months or longer) and those who may be exposed to blood or semen should consider vaccination.
Unvaccinated individuals who are exposed to a known case of hepatitis B or to a person at high risk for hepatitis B should be evaluated by a physician. Examples of such exposures include needle stick injuries in health care workers or sexual intercourse with an infected person. If the exposure is significant, the physician will recommend vaccination and may also recommend an injection of hepatitis B immune globulin (HBIG). HBIG is prepared from the plasma of blood donors and contains antibodies to hepatitis B. Vaccination and HBIG can substantially reduce the risk of disease in persons exposed to hepatitis B if given within one week of a needle stick or two weeks of sexual intercourse.
Vaccination provides long-term immunity in people who respond to the vaccine. There is no need for HBIG if an exposure occurs to a vaccinated person who is known to have responded to the vaccine; however, a blood test might be drawn to verify that the person did respond to the vaccine and form antibodies.
Infected mothers can pass hepatitis B to their newborn infants. All pregnant women should have blood drawn to determine if they are infected. Infants born to infected mothers should receive HBIG and hepatitis B vaccine at birth. This is 85% to 95% effective in eliminating the risk of hepatitis B infection in the infant.
REFERENCE: Centers for Disease Control and Prevention. Hepatitis A Vaccine.
Centers for Disease Control and Prevention. Hepatitis B Vaccine.
Top Hepatitis Immunizations Related Articles
Bilirubin and Bilirubin Blood TestBilirubin is a waste product of the normal breakdown of red blood cells in the liver. Normal bilirubin levels vary from lab to lab, and range from around 0.2 to 1.2 mg/dL. High levels of bilirubin can be diagnosed with a bilirubin blood test. Causes of elevated levels of bilirubin in the blood can be caused by infections, viral hepatitis, anemia, genetic diseases, and liver problems. Symptoms of elevated bilirubin levels depend on the cause; however, jaundice is a common sign. Treatment for elevated bilirubin levels depend on the cause.
Childhood Vaccination ScheduleChildhood immunizations can protect children from potentially deadly diseases. Vaccinations included on the childhood immunization schedule include Hib, polio, DTaP, MMR, HPV, flu, chickenpox, meningitis, rotavirus, pneumonia, hepatitis A, and hepatitis B.
CirrhosisCirrhosis of the liver refers to a disease in which normal liver cells are replaced by scar tissue caused by alcohol and viral hepatitis B and C. This disease leads to abnormalities in the liver's ability to handle toxins and blood flow, causing internal bleeding, kidney failure, mental confusion, coma, body fluid accumulation, and frequent infections.
Symptoms include yellowing of the skin (jaundice), itching, and fatigue.
The prognosis is good for some people with cirrhosis of the liver, and the survival can be up to 12 years; however the life expectancy is about 6 months to 2 years for people with severe cirrhosis with major complications.
Hepatitis B PictureInflammation of the liver due to the hepatitis B virus (HBV), once thought to be passed only through blood products. See a picture of Hepatitis B and learn more about the health topic.
Hepatitis CHepatitis C is an inflammation of the liver due to the hepatitis C virus (HCV), which is usually spread by blood transfusion, hemodialysis, and needle sticks, especially with intravenous drug abuse. Symptoms of chronic hepatitis include fatigue, fever, muscle aches, loss of appetite, and fever. Chronic hepatitis C may be cured in most individuals with drugs that target specific genomes of hepatitis C.
Hepatitis SlideshowWhat is hepatitis? Hepatitis A, B, and C spread in different ways, causing mild to serious effects on the liver. Learn about hepatitis symptoms and available vaccines to prevent hepatitis infection.
Hepatitis Risk SlideshowSee how Hepatitis types A, B and C are trasmitted through issues such as poor hygiene, contamination, sexual contact and more.
ImmunizationsImmunizations can prevent many diseases nowadays. It's important to follow the vaccination guidelines recommended on the CDC's vaccination schedule for adults and adolescents in order to stay informed about new vaccines and to learn how often and when the vaccines should be administered.
Liver (Anatomy and Function)The liver is the largest gland and organ in the body. There are a variety of liver diseases caused by liver inflammation, scarring of the liver, infection of the liver, gallstones, cancer, toxins, genetic diseases, and blood flow problems. Symptoms of liver disease generally do not occur until the liver disease is advanced. Some symptoms of liver disease include jaundice, nausea and vomiting, easy bruising, bleeding excessively, fatigue, weakness, weight loss, shortness of breath, leg swelling, impotence, and confusion. Treatment of diseases of the liver depend upon the cause.
Liver Blood TestsAn initial step in detecting liver damage is a simple blood test to determine the presence of certain liver enzymes in the blood. Under normal circumstances, these enzymes reside within the cells of the liver. But when the liver is injured, these enzymes are spilled into the blood stream, and can lead to diseases like fatty liver, type 2 diabetes, obesity, and hepatitis. Several medications also can increase liver enzyme test results.
Liver DiseaseLiver disease can be cause by a variety of things including infection (hepatitis), diseases such as:
- high cholesterol or triglycerides,
- blood flow obstruction to the liver, and
- toxins (medications and chemicals).
- upper right abdominal pain, and
Liver Disease QuizWhat is liver disease? Take the Liver Disease Quiz and test your knowledge about this organ and its function.
STDs in Men Overview
Sexually transmitted diseases (STDs) are infections transmitted during sexual contact. They may be caused by viruses, bacteria, or parasites. STDs in men cause no symptoms or symptoms like
genital burning, itching, sores, rashes, or discharge.
Common infections that are sexually transmitted in men include gonorrhea, chlamydia, syphilis, hepatitis C and B, genital warts, human papillomavirus (HPV), and genital herpes.
Some STDs in men are treatable while others are not. STDs are diagnosed with tests that identify proteins or genetic material of the organisms causing the infection. The prognosis of an STD depends on whether the infection is treatable or not. Use of latex condoms can help reduce the risk of contracting an STD but it does not eliminate the risk entirely.
Travel Health SlideshowExplore travel health tips and vaccines to prevent disease while abroad. Learn to protect yourself against malaria, hepatitis, tetanus and more by learning which vaccines or health precautions are advised for your destination.
Vaccination FAQsVaccinations increase our ability to fight diseases that may be contagious or even fatal. Immunity occurs by getting the disease or through the use of a vaccine. There are two types of vaccine: inactivated vaccines and vaccines made from live, weakened viruses.
Viral InfectionsWatch this slideshow on Viral Infections and learn about types, treatment, and prevention of illnesses caused by viruses.