Hepatitis B is an extremely contagious liver infection caused by the hepatitis B virus (HBV), and it can cause severe liver damage or liver cancer in a small percentage of patients. A person can get a hepatitis B immunity two ways. Today, the most common way to get an immunity to this disease is by getting vaccinated. Individuals who have already had the disease and recovered from it also develop an immunity, which is known as a natural immunity to hepatitis B.
Alfred Prince, a virologist, invented the hepatitis vaccine in 1968, and it was first available for use in 1981. This vaccine involves injecting people with weakened portions of the hepatitis B virus. This helps a person's body produce antibodies, which help build a hepatitis B immunity.
The hepatitis B vaccine is a common vaccine today, especially in developed countries. Most people today who have a hepatitis B immunity gained it through a vaccine. Usually, it is given in three doses shortly after a child is born. The fist is given almost immediately after the baby is born, and the second is given about a month later. The third and final dose of the hepatitis B vaccine is usually given roughly six months later, but doctors can wait until 18 months.
Many doctors also recommend the vaccine be used on adults who are at a higher risk of contracting the virus and have not been vaccinated or built a natural hepatitis B immunity. Gay men, people with more than one sexual partner, and people who use illegal intravenous street drugs, such as heroin, are all at a higher risk of contracting hepatitis B. Individuals with certain diseases, such as liver disease and HIV, should also consider getting vaccinated. Because they come in close contact with those carrying the virus, most countries require that anyone working in a health care job also get vaccinated.
Like many other vaccines, there are some people who should not get this vaccine. Since some modern hepatitis B vaccines are grown in yeast, people with an allergy to baker's yeast should not get this vaccine. Also, anyone who had a prior allergic or otherwise negative reaction to a hepatitis vaccine should refrain from getting his vaccine.
A natural hepatitis B immunity is also possible. This type of immunity occurs after a person contracts the disease. Most people who contract HPV fully recover from the illness and develop this immunity. A few, however, develop chronic hepatitis B, while others may become HBV carriers. A hepatitis B carrier usually has no symptoms of the disease, but he can still spread hepatitis B to other people.