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How Is Hepatitis B Vaccine Made

Do The Benefits Of The Hepatitis B Vaccine Outweigh Its Risks

HBV Vaccine – Creative Biolabs

Every year in the United States about 2,000 people die following an overwhelming hepatitis B virus infection. In addition, every year about 22,000 people are infected with hepatitis B. Some of them will remain chronically infected, putting them at high risk of the long-term consequences of hepatitis B virus infection: cirrhosis and liver cancer. In fact, with the exception of influenza and COVID-19 viruses, hepatitis B virus causes more severe disease and death in the United States than any other vaccine-preventable disease. On the other hand, the hepatitis B vaccine is an extremely rare cause of a severe allergic reaction called anaphylaxis. To date, no one has died from this reaction, but it is theoretically possible that this could occur.

Because hepatitis B virus is a common cause of severe disease and death in the United States, and because the hepatitis B vaccine does not cause permanent damage or death, the benefits of the hepatitis B vaccine clearly outweigh its risks.

Therapeutic Hepatitis B Vaccine

It is known that the clearance of HBV in host requires both the innate and adaptive humoral and cellular immune responses. The elimination of virions in hepatocytes is mainly dependent upon the T-cell responses. Thus, great efforts have been taken to develop therapeutic hepatitis B vaccine using different genes of HBV, including P, C, S and/or pre-S gene, with various techniques, based on protein, protein-antibody complex, peptide, or DNA, to stimulate the humoral and/or cellular immune responses.3740 However, although the therapeutic vaccines elicited specific humoral and/or cellular immune responses in human or experimental animals and showed promising therapeutic effects in some experimental animals,37,38 the clinical efficacy of the therapeutic vaccines is limited.4042 Thus, far more breakthrough studies are required to develop effective therapeutic vaccines against hepatitis B in human.

Implementing Strategies For Hepatitis B Vaccination

When hepatitis B vaccines became available, strategies for HBV control were initially focused on vaccination of high-risk groups . However, high-risk individuals are mostly difficult to reach and are often infected before vaccination . Consequently, coverage of 3 doses of hepatitis B vaccine remained low in most high-risk groups due to low compliance and logistic reasons . In addition, as many as 30% or more people with acute hepatitis B infection do not have identifiable risk factors and are therefore missed by only a high-risk group approach .

Hence it was clear that an additional global strategy was required as the high-risk strategy made little impact and the global burden of hepatitis B diseases became more and more obvious. Decision makers and health professionals worldwide started to discuss a strategy of universal hepatitis B immunization for a certain age cohort, even in low-endemicity countries. In 1991, the WHOs Global Advisory Group of the Expanded Programme on Immunization recommended that hepatitis B vaccine be integrated into national immunization programs in all countries by 1997 . This 1991 recommendation was endorsed by the World Health Assembly in 1992 . Progressively, it has become more widely used and recommendations for HBV vaccination have been extended in an attempt to achieve maximum protection .

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The Impact Of Worldwide Hepatitis B Vaccination Programs: Model Of Success

A, Immunization coverage with third dose of hepatitis B in infants in 2019. B, Global immunization 19892019 HepB3 coverage in infants. Global coverage was 84% in 2019. Abbreviations: AFR,African region AMR,Americas region EMR,Eastern Mediterranean region EUR,European region SEAR,South-East Asia region WPR,Western Pacific region. Source: United Nations Children’s Fund /World Health Organization.

The success of HBV vaccination programs has been clearly demonstrated over the recent years in several regions around the world. Countries that have adopted the recommendation had a marked reduction in carrier rates as well as complications from HBV, including HCC. The low prevalence of chronic HBV infection in children younger than 5 years, reducing from 4.7% in the prevaccine era to less than 1% in 2019, can be attributed to the widespread use of hepatitis B vaccine. Due to the implementation of routinely birth-dose vaccination the greatest decrease appears to be in the Western Pacific region, from 8.3% HBsAg prevalence in the prevaccine era to 0.93% in 20022015 . Among health care workers, hepatitis B vaccination is highly effective for the prevention of healthcare associated HBV infection and chronic infection. Using mathematical models, it was estimated that since their implementation, HBV vaccination programs have averted 210 million new HBV infections globally .

Persons With Chronic Diseases

Asian Health Disparities and Hepatitis B in the Era of Elimination ...

Refer to Immunization of Persons with Chronic Diseases in Part 3 for additional general information about vaccination of people with chronic diseases.

Chronic renal disease and patients on dialysis

People with chronic renal disease may respond sub-optimally to HB vaccine and experience more rapid decline of anti-HBs titres, and are therefore recommended immunization with a higher vaccine dose. Individuals undergoing chronic dialysis are also at increased risk for HB infection. In people with chronic renal disease anti-HBs titre should be evaluated annually and booster doses using a higher vaccine dose should be given as necessary.

Neurologic disorders

People with conditions such as autism spectrum disorders or demyelinating disorders should receive all routinely recommended immunizations, including HB-containing vaccine.

Chronic liver disease

HB immunization is recommended for non-immune persons with chronic liver disease, including those infected with hepatitis C, because they are at risk of more severe disease if infection occurs. Vaccination should be completed early in the course of the disease, as the immune response to vaccine is suboptimal in advanced liver disease. Post-immunization serologic testing may be used to confirm vaccine response.

Non-malignant hematologic disorders

Persons with bleeding disorders and other people receiving repeated infusions of blood or blood products are considered to be at higher risk of contracting HB and should be offered HB vaccine.

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The 1970s Vaccine Success

During the 1970s, one vaccine was eliminated. Because of successful eradication efforts, the smallpox vaccine was no longer recommended for use after 1972. While vaccine research continued, new vaccines were not introduced during the 1970s.

Late 1970s | Recommended Vaccines

* Given in combination as DTP** Given in combination as MMR

Why Do You Need A Hepatitis B Shot

Hepatitis B is a viral infection that cant be transferred person-to-person unless you have contact with an infected persons bodily fluids. Annual infection rates of HBV are going down in the United States thanks to vaccines. So you might be wondering if you or your child needs a shot to protect against hepatitis B.

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Preparations Of Hepatitis B Vaccine

Hepatitis B vaccine is produced using recombinant DNA technology. A plasmid containing the gene for hepatitis B surface antigen is inserted into common bakers yeast, which then produces HBsAg. The HBsAg is harvested and purified. This vaccine cannot cause hepatitis B virus infection because no potentially infectious viral DNA or complete viral particles are produced during this process.

Single-antigen and a combination formulation that combines hepatitis A and hepatitis B vaccines are available. Two single-antigen vaccines, Engerix-B® and Recombivax HB®, are conjugated with aluminum. A newer formulation, HepB-CpG , uses the immune-stimulating adjuvant, cytidine-phosphate-guanosine oligodeoxynucleotide .

Who Should Not Get The Hepatitis B Vaccine

Should adults be vaccinated against Hepatitis B – Dr. Ravindra B S

Hepatitis B is a safe vaccine that does not contain a live virus.

However, there are some circumstances in which doctors advise against getting the HBV vaccine.

You should not receive the hepatitis B vaccine if:

  • youve had a serious allergic reaction to a previous dose of the hepatitis B vaccine
  • you have a history of hypersensitivity to yeast or any other HBV vaccine components

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Dose And Administration Of Hepatitis B Vaccine

The dose for Engerix-B® and Recombivax HB® is 0.5 mL IM up to age 20 years or 1 mL IM for adults . The dose for Heplisav-B® is 0.5 mL IM for adults 18 years.

The vaccine is typically given to children in a 3-dose series at age 0 months, at 1 to 2 months, and at 6 to 18 months.

Infants who did not receive a dose a birth should begin the series as soon as feasible.

All children not previously vaccinated with HepB vaccine should be vaccinated at age 11 or 12 years. A 3-dose schedule is used the 1st and 2nd doses are separated by 4 weeks, and the 3rd dose is given 4 to 6 months after the 2nd dose. However, a 2-dose schedule using Recombivax HB® can be used the 2nd dose is given 4 to 6 months after the first.

The usual schedule for adults using Engerix-B® or Recombivax HB® is a 3-dose series with 2 doses separated by 4 weeks, and a 3rd dose 4 to 6 months after the 2nd dose. Heplisav-B® is given in 2 doses at least 4 weeks apart and can be given as a substitute in a 3-dose series with a different HepB vaccine. Heplisav-B® should not be given during pregnancy because safety data are not available on its use during pregnancy.

Unvaccinated adults who are being treated with hemodialysis or who are immunocompromised should be given 1 dose of Recombivax HB® 40 mcg/mL in a 3-dose schedule at 0, 1, and 6 months or 2 doses of Engerix-B® 20 mcg/mL given simultaneously in a 4-dose schedule at 0, 1, 2, and 6 months.

What Is The Transmission Route Of Hbv

Today, we know that HBVs are highly infectious and are spread by exposure of mucosal membranes or nonintact skin to infected blood or other body fluids . In high endemic areas, HBV is most commonly transmitted from mother to child at birth and during early childhood from infected to uninfected children . Most HBV infections in areas of low endemicity occur in adults in relatively well-defined risk groups, such as those at risk through sexual exposure, household members of an infected person, hemodialysis patients, incarcerated persons, injection-drug users, persons at risk for occupational exposure, developmentally disabled persons in long-term care facilities, and travelers to regions with moderate or high HBV endemicity. Today, only humans are a known reservoir for human HBV genotypes, but closely related HBV genotypes exist in higher primates . Hence, a comprehensive control strategy could eventually lead to the eradication of HBV.

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Plasma Hepatitis B Vaccine

HBV cannot efficiently replicate in cell cultures, indicating that it is impossible to develop hepatitis B vaccine based on in vitro culture system. Dr Krugman and his colleagues conducted the pioneering work on developing hepatitis B vaccine. They showed that boiling destroyed the infectivity of HBV carriers plasma,3 active immunization of individuals with the boiled plasma induced antibodies against HBsAg and the immunized subjects were partially protected against HBV challenge,4 and hepatitis B immunoglobulin showed effective in preventing HBV infection in human.5 These studies demonstrated the possibility of viral antigens naturally produced in HBV carriers in developing hepatitis B vaccine.

Electron microscopy found that the 22-nm spherical particles in the circulation of HBV carriers are much excess over the 42-nm HBV virions,2 and the concentration of circulation HBsAg is as high as 200 µg/mL.6 Meanwhile, chimpanzees were found to be susceptible to human HBV infection,7 which provided an animal model to evaluate the efficacy and safety of hepatitis B vaccine. Given the high concentrations of circulation HBsAg, HBsAg purified from the plasma of asymptomatic carriers had been extensively studied to develop the hepatitis B vaccine.

Vaccine Development In The 1980s Hepatitis B And Haemophilus Influenzae Type B

Hepatitis

The vaccine for Haemophilus influenzae type b was licensed in 1985 and placed on the recommended schedule in 1989. When the schedule was published again in 1994, the hepatitis B vaccine had been added.

The hepatitis B vaccine was not new, as it had been licensed in 1981 and recommended for high-risk groups such as infants whose mothers were hepatitis B surface antigen positive, healthcare workers, intravenous drug users, homosexual men and people with multiple sexual partners. However, immunization of these groups didn’t effectively stop transmission of hepatitis B virus. Thats because about one-third of patients with acute disease were not in identifiable risk groups. The change of recommendation to immunize all infants in 1991 was the result of these failed attempts to control hepatitis B by only immunizing high-risk groups. Following this recommendation, hepatitis B disease was virtually eliminated in children less than 18 years of age in the United States.

1985 – 1994 | Recommended Vaccines

* Given in combination as DTP** Given in combination as MMR

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Universal Hepatitis B Vaccination

Since the recombinant DNA technology can produce unlimited supplies of hepatitis B vaccine, it becomes feasible to prepare sufficient hepatitis B vaccine for the worldwide use. The World Health Organization recommended in 1991 that all countries implement universal hepatitis B vaccination by 1997 to prevent and control on a global scale HBV infection.74 This recommendation promoted all countries to incorporate hepatitis B vaccine into their national immunization program. However, worldwide implementation of universal vaccination is not an easy task. By 2000, only 116 of 215 countries adopted this policy, representing 31% of the global birth cohort.75 In hepatitis B endemic regions, where economics is usually less developed, lack of funds is the main reason, whereas in the low-endemic regions, universal infant vaccination appears to be less importance, leading to reluctant to adopt this policy. Japan and UK did not take the universal vaccination policy until 2016 and 2017, respectively.7678

What Is Hepatitis B

Hepatitis B is a highly contagious liver infection caused by the hepatitis B virus . The infection can range in severity from mild to acute. It may last just a few weeks or become a serious, chronic, and potentially fatal health condition.

The best way to prevent this infection is to get the hepatitis B vaccine. Heres what you need to know.

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The Hepatitis B Vaccine

The hepatitis B vaccine is used to prevent hepatitis B. Its usually provided in three doses.

The first dose can be taken on a date you choose. The second dose must be taken 1 month later. The third and final dose must be taken 6 months after the first dose.

Some people may need two or four doses of this vaccine.

There is also a newer hepatitis B vaccine thats offered in two doses.

Why A Variety Of Hepatitis B Vaccine Schedules Have Been Used

Bloodborne Pathogens Training – The Hepatitis Vaccine

Generally, the recommended number of doses of hepatitis B vaccine required to induce protective immunity varies by product and with the age of the recipient. Historically, the standard 3-dose hepatitis B vaccine series has consisted of 2 priming doses administered 1 month apart and a third dose administered 6 months after the first dose. Today, the WHO recommends multiple options for adding hepatitis B vaccine to existing infant immunization schedules. Several options are considered to be appropriate for infants: 1 birth dose followed by either 2 doses of monovalent or hepatitis B containing combination vaccine at 1 and 6 months of age or at 2, 4, and 6 months of age or at 3, 5, and 11 months of age or at 8, 12, 16 weeks and 12 or 15 months or at 6, 10, and 14 weeks of age, according to the WHOs Expanded Programme on Immunization schedule . Currently, a variety of hepatitis B vaccine schedules have been used successfully worldwide. In general, preference is given to effective options that require minimal additional visits for immunization, to increase compliance and to reduce the logistics burden.

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Hepatitis B Vaccination In Pregnancy

Hepatitis B infection in pregnant women may result in severe disease for the mother and chronic infection for the baby.

This is why the hepatitis B vaccine is recommended for pregnant women who are in a high-risk category.

There’s no evidence of any risk from vaccinating pregnant or breastfeeding women against hepatitis B.

And, as it’s an inactivated vaccine, the risk to the unborn baby is likely to be negligible .

Hepatitis B Vaccine: Canadian Immunization Guide

For health professionals

Last partial content update : May 2022

The footnotes in and the accompanying text description for the figure have been revised to align with the corresponding figure in Protocole d’immunisation du Québec, 5e édition from which it was adapted.

Last complete chapter revision :

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Hbv Vaccination Doses And Formulations

Given differences in the manufacturing processes and populations vaccinated, the quantity of HBsAg protein per dose that will induce a protective immune response differs in various vaccine products. Currently, hepatitis B vaccines are formulated to contain 540 g of recombinant HBsAg protein and an aluminum phosphate or aluminum hydroxide adjuvant . In general, based on immunogenicity data with different vaccine dosages in different age groups, the vaccine dosages to provide protection for infants, children, and adolescents are 50% lower than that required for adults . Marketed hepatitis B vaccines are to be administered by intramuscular injection on the anterolateral site of the thigh or into the deltoid muscle . The WHO has developed recommendations to ensure the quality, safety, and efficacy of recombinant hepatitis B vaccines and keeps a list of current hepatitis B vaccines prequalified by the WHO .

Hepatitis B vaccines are available as monovalent formulations for birth doses or for vaccination of adult persons at risk, and as combination vaccines . Major progress in the global response to viral hepatitis has been achieved through the introduction of routine hepatitis B vaccination via the WHOs Expanded Programme on Immunization, which was facilitated by the introduction of combination vaccines . Hepatitis B vaccines are generally stable for 3 to 4 years from the date of manufacture if stored between 2°C and 8°C.

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