Hepatitis B vaccine is a vaccine that prevents hepatitis B. The first dose is recommended within 24 hours after birth with two or three more doses given afterwards. These include those with poor immune function such as from HIV/AIDS and those born prematurely. It is also recommended for health workers to be vaccinated. In healthy people routine immunization results in more than 95% of people who are protected.
Blood tests to verify that the vaccine has been successfully recommended in those at high risk. Additional doses may be needed in people with poor immune function but are not needed for most people. In those who have been exposed to the hepatitis B virus but not immunized, immune hepatitis B globulin should be given in addition to the vaccine. The vaccine is given by injection to the muscle.
Serious side effects of hepatitis B vaccine are very rare. Pain can occur at the injection site. Safe to use during pregnancy or while breastfeeding. It has not been associated with Guillain-Barrà ©  © © syndrome. The vaccine is currently produced by recombinant DNA techniques. They are available on their own and combined with other vaccines.
The first hepatitis B vaccine was approved in the United States in 1981. The recombinant version appeared on the market in 1986. It is a List of Essential Medicines of the World Health Organization, the most effective and safe drugs needed in the health system. In 2014, wholesale costs in developing countries are US $ 0.58 to 13.20 per dose. In the United States it costs US $ 50-100.
Video Hepatitis B vaccine
Medical use
Hepatitis B vaccination, hepatitis B immunoglobulin, and a combination of hepatitis B vaccine plus hepatitis B immunoglobulin are all considered as preventative for infants born to mothers infected with HBV. This combination is superior to protecting these babies. Vaccines during pregnancy are not considered valuable in protecting infants from infected mothers. Immunoglobulin hepatitis B before birth has not been well studied.
In the United States vaccination is recommended for almost all infants at birth. Many countries now routinely vaccinate infants against hepatitis B. In countries with high rates of hepatitis B infection, newborn vaccination not only reduces the risk of infection but also causes marked declines in liver cancer. This was reported in Taiwan where the implementation of the national hepatitis B vaccination program in 1984 was associated with a decrease in the incidence of childhood hepatocellular carcinoma.
In the UK, vaccines are offered to MSM, usually as part of sexual health checks. A similar situation is operating in Ireland.
In many areas, vaccination against hepatitis B is also required for all healthcare and laboratory staff. Both types of vaccines, plasma-derived vaccines (PDVs) and recombinant vaccines (RVs), appear to be capable of generating similar levels of anti-HBs.
The Centers for Disease Control and Prevention has issued recommendations for vaccination against hepatitis B among patients with diabetes mellitus. The World Health Organization recommends pentavalent vaccines, combining vaccines against diphtheria, tetanus, pertussis and type B baemophilus influenzae with vaccines against hepatitis B. There is not enough evidence yet of how effective these pentavalent vaccines are in relation to each vaccine.
Effectiveness
Following the main program of 3 vaccinations, blood tests can be taken after an interval of 1-4 months to determine whether there has been an adequate response, defined as anti-hepatitis B surface antigen (anti-Hbs) antibody levels above 100 mIU/ml. Such a full response occurs in about 85-90% of individuals.
An antibody level between 10 and 100 mIU/ml is considered a bad response, and these people should receive a single booster vaccine at this time, but there is no need for further retesting.
People who fail to respond (anti-Hbs levels below 10 mIU/ml) should be tested to rule out previous or previous Hepatitis B infections, and repeat 3 vaccinations, followed by further re-testing 1-4 months after the second course. Those still unable to respond to the second vaccination program may respond to intradermal or high dose or double dose vaccine from combined hepatitis A and B vaccines. Those who still fail to respond will require hepatitis B immunoglobulin (HBIG) if later exposed to hepatitis B virus.
Bad responses are mostly associated with age above 40 years, obesity and smoking, and also in alcoholics, especially if with advanced liver disease. Patients with immunosuppression or renal dialysis may respond poorly and require larger or more frequent vaccine doses. At least one study showed that hepatitis B vaccination was less effective in patients with HIV.
Duration of protection
It is now believed that the hepatitis B vaccine provides unlimited protection. However, it was previously believed and suggested that vaccination would only provide an effective cover between five and seven years, but it has subsequently been appreciated that long-term immunity stems from an immunological memory that lives longer than loss of antibody levels and hence subsequent testing and booster dosage is not required in immunocompetent individuals who were successfully vaccinated. Therefore with the passage of time and longer experience, protection has been demonstrated for at least 25 years in those who demonstrated an adequate initial response to the major vaccination programs, and the UK guidelines now suggest that for early responders requiring ongoing protection, such as for service personnel health, only one amplifier is advocated at 5 years.
Maps Hepatitis B vaccine
Side effects
Serious side effects of hepatitis B vaccine are very rare. Pain can occur at the injection site. Safe to use during pregnancy or while breastfeeding. It has not been associated with Guillain-Barrà ©  © © syndrome.
Multiple sclerosis
Several studies have sought an association between recombinant hepatitis B vaccine (HBV) and multiple sclerosis (MS) in adults. Most studies do not support a causal relationship between hepatitis B vaccination and demyelinating disease such as MS. A 2004 study reported a significant increase in risk within 3 years of vaccination. Some of these studies were criticized for methodological problems. This controversy creates public doubt about HB vaccinations, and hepatitis B vaccinations in children remain low in some countries. A 2006 study concluded that the evidence does not support the association between HB vaccination and sudden infant death syndrome, chronic fatigue syndrome, or multiple sclerosis. A 2007 study found that vaccination did not seem to increase the risk of the first episode of MS in childhood.
Usage
The following is a list of countries based on the percentage of infants who received three doses of hepatitis B vaccine as published by the World Health Organization in 2014.
History
The road to hepatitis B vaccine began in 1963 when American physician/geneticist Baruch Blumberg discovered what he called "Australian Antigen" (now called HBsAg) in the Australian Aboriginal serum. In 1968, this protein was found to be part of a virus that causes "serum hepatitis" (hepatitis B) by virologist Alfred Prince. American microbiologist/vaccinologist Maurice Hilleman at Merck uses three serum blood (pepsin, urea and formaldehyde) treatments together with strict filtration to produce products that can be used as safe vaccines. Hilleman hypothesizes that he can make HBV vaccine by injecting patients with hepatitis B surface proteins. Theoretically, this would be very safe, because the excess of this surface protein lacks infectious viral DNA. The immune system, which recognizes surface proteins as foreign bodies, will produce special-shaped antibodies, tailor-made to bind, and destroy, these proteins. Then, in the future, if the patient is infected with HBV, the immune system can immediately spread protective antibodies, destroying the virus before they can be harmful.
Hilleman collects blood from gay men and injecting drug users - groups known to be at risk for viral hepatitis. This happened in the late 1970s, when HIV was unknown drugs. In addition to the hepatitis B surface protein sought, blood samples are likely to contain HIV. Hilleman devised a multistep process to purify this blood so that only remaining hepatitis B surface protein. Any known virus is killed by this process, and Hilleman believes the vaccine is safe.
The first large-scale trial for a blood-derived vaccine was performed in gay men, according to their high-risk status. Then, Hilleman's vaccine is misused to trigger an AIDS epidemic. (See Wolf Szmuness) However, although the purified blood vaccine appears questionable, it is determined to be completely HIV-free. The purification process has destroyed all viruses - including HIV. The vaccine was approved in 1981.
The blood-derived hepatitis B vaccine was withdrawn from the market in 1986 when Pablo DT Valenzuela, Chiron Corporation's Research Director, managed to make the antigen in yeast and found the world's first recombinant vaccine. Recombinant vaccines are developed by introducing the HBV gene encoding the surface protein into Saccharomyces cerevisiae yeast. This allows the yeast to produce only non-infectious surface proteins, without the danger of introducing actual viral DNA into the final product. This is a vaccine that is still in use today.
In 1976, Blumberg had won the Nobel Prize in Physiology or Medicine for his work on hepatitis B (sharing with Daniel Carleton Gajdusek for his work on kuru). In 2002, Blumberg published a book, Hepatitis B: The Hunt for a Killer Virus . In this book, according to biographer Paul A. Offit - Hilleman and a vaccinologist himself - Blumberg...
... claimed that the hepatitis B vaccine was his discovery. Maurice Hilleman's name is mentioned once... Blumberg fails to mention that Hilleman has discovered how to disable hepatitis B virus, how to kill all other contaminated viruses, how to remove all other proteins found in human blood, and how to do all this while maintaining the structural integrity of surface proteins. Blumberg has identified the Australian antigen, an important first step. But all the other steps - which are essential for making the vaccine - belong to Hilleman. Then, Hilleman recalled, "I think [Blumberg] deserves much credit, but he does not want to reward anyone."
Producing
This vaccine contains one of the envelope virus proteins, hepatitis B surface antigen (HBsAg). Now produced by yeast cells, where the genetic code for HBsAg has been included. After that the immune system antibodies to HBsAg are established in the bloodstream. These antibodies are known as anti-HBs . The memory of these antibodies and immune systems then provides immunity to HBV infection.
Brand name
Common brands available are the Recombivax HB (Merck), Engerix-B (GSK), Elovac B (Institute of Human Biology, a division of India Immunologicals Limited), Genevac B (Serum Institute), Shanvac B , etc. This vaccine is given by the intramuscular route. By the end of 2017, the FDA approved a new vaccine called Heplisav-B from Dynavax Technologies Corps. This two dose vaccine will compete with the three-dose Engerix-B vaccine.
Twinrix is ​​a vaccine against hepatitis A and hepatitis B.
Research
Injectable Hepatitis B vaccines require expensive production and cooling processes, which can make them difficult to access in developing countries. As a result, researchers have been working to engineer plants that are capable of producing the materials needed to make vaccines so people can eat these plants to receive vaccines. Potatoes, bananas, lettuce, carrots, tobacco are some genetically engineered plants to produce hepatitis B vaccine.
The process of genetically engineered crops to produce vaccines includes extracting genes that encode the Hepatitis B surface antigen from the Hepatitis B genome, and place it in a bacterial plasmid. The bacteria then infect the plant, which will produce surface antigen. When a man eats a plant, his body is stimulated to produce an antibody response to the surface antigen. Although concerns persist in improving the efficacy of edible vaccines, controlling vaccine doses at each plant, and managing land allocations for this process, scientists consider this a promising avenue for vaccinating less-developed areas of the world.
References
External links
Source of the article : Wikipedia
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