Unraveling Key Determinant of Chronic Hepatitis B Vaccination

Donald Hackett — Mon, 16 Jan 2023 17:44:16 +0000

Reviewer:

The role of viral hepatitis as a public health threat has long been underestimated. For example, over 800,000 people die each year from the consequences of a hepatitis B virus (HBV) infection.

The United Nations' 2030 Agenda for Sustainable Development project recently called for action to reduce this global disease.

While prophylactic vaccines are available to prevent HBV infection, more than 3% of the world's population are chronically infected and do not benefit.

In response, a research team from Germany recently announced they highlighted the success of therapeutic hepatitis B vaccination depends on the efficient priming of HBV-specific CD4 T cells.

These researchers from the Institute of Virology at Helmholtz Munich, the Technical University of Munich, and the German Center for Infection Research found the benefits of heterologous prime-boost vaccination deliver a more robust and longer-lasting immunity.

Most essential is the optimization of TherVacB prime- and boost vaccination strategies requires a thorough understanding of which vaccine component activates the different immune system cells, like T- or B cells.

These factors are essential for breaking immune tolerance in HBV carriers and determining a successful outcome of therapeutic vaccination.

Therapeutic vaccination is a promising, potentially curative treatment for chronic hepatitis B, wrote these researchers on January 9, 2023.

This study provides the first direct evidence that efficient priming of HBV-specific CD4 T cells determines the success of therapeutic hepatitis B vaccination in two preclinical HBV-carrier mouse models.

Applying an optimal formulation of HBV antigens that allows activating CD4 and CD8 T cells during prime immunization provided the foundation for an antiviral effect of therapeutic vaccination.

While depletion of CD4 T cells leads to a complete loss of vaccine-induced antiviral efficacy.

Boosting CD8 T cells was essential to control HBV in these mouse models.

Our findings provide important insights into the rational design of therapeutic vaccines to cure chronic hepatitis B, wrote these researchers.

This study also confirms and expands the textbook knowledge in a concrete case and underlines the importance of the prime vaccination to nudge the immune system in the desired direction.

It thus serves to develop or improve therapeutic vaccines against chronic hepatitis B - and maybe other chronic or malignant diseases - and hopefully help to accelerate the progress towards a cure for chronic hepatitis B, which will be a great benefit for millions of hepatitis B patients worldwide, wrote these researchers.

This research was published in the Journal of Hepatology on January 9, 2023. This project received funding from the German Research Foundation and others. No industry conflicts of interest were disclosed.

In the U.S., the Advisory Committee on Immunization Practices recommends various people receive hepatitis B vaccination. Other hepatitis B vaccine news is posted at PrecisionVaccinations.

Sub Title:

Therapeutic hepatitis B vaccine activates CD4 T cells during prime immunization

References:

Activation of CD4 T cells during prime immunization determines the success of a therapeutic hepatitis B vaccine in HBV-carrier m

Determinant of successful therapeutic vaccination against chronic hepatitis B

World Hepatitis Day

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Google News Keywords:

Hepatitis B, vaccinations

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Fact checked:

Tuesday, January 17, 2023 - 05:30

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Journal of Hep, Jan 2023 - Activation of CD4 T cells during prime immunization

Three Antigen Hepatitis B Vaccine Found Effective

Don Hackett — Tue, 19 Oct 2021 13:06:14 +0000

Reviewer:

Robert Carlson, MD

Massachusetts-based VBI Vaccines Inc. recently announced that Phase 3 study results of its prophylactic 3-antigen hepatitis B (HBV) vaccine candidate were published in The JAMA Network Open.

The CONSTANT study was designed to demonstrate manufacturing equivalence of three lots of VBI’s HBV vaccine candidate and evaluate the immunogenicity of VBI’s 3-antigen HBV vaccine candidate compared to a single-antigen HBV vaccine, Engerix-B®, after two and three doses, and safety and reactogenicity.

The primary endpoint of lot-to-lot manufacturing consistency, measured by GMC of anti-HBs concentration at Day 196 across three consecutively manufactured lots of VBI’s 3-antigen HBV vaccine candidate, was achieved.

And SPR after two doses, at Day 168, was 90.4% for VBI’s 3-antigen vaccine candidates compared to 51.6% for Engerix-B®, increasing to 99.3% and 94.8%, respectively, after the third dose.

The mean GMC of anti-HBs titers was more than 7.5x higher after two doses, at Day 168, and 3.5x higher after three doses, at Day 196 (5442.4 mIU/mL VBI vs. 1567.2 mIU/mL Engerix-B).

Furthermore, VBI’s 3-antigen vaccine also elicited a higher percentage of participants with anti-HBs titers ≥ 100 mIU/mL, a more stringent titer threshold, of 95.8% vs. 86.3% for Engerix-B at Day 196.

No safety signals were observed in either study arm, and no new safety risks were identified.

Together with results from the first pivotal Phase 3 study, PROTECT, these results formed the basis for the regulatory submissions of VBI’s 3-antigen HBV vaccine candidate in the U.S., Europe, and Canada.

This HBV vaccine is sold under the name Sci-B-Vac® in Israel.

Dr. Timo Vesikari, M.D., Ph.D., Professor Emeritus and Director of the Nordic Vaccine Research Network in Finland, principal investigator of the CONSTANT study, and author of the manuscript commented, commented in a related press statement issued on October 13, 2021, “In North America and Europe, adults age 25-49 years have the highest rates of HBV infection.”

“Unfortunately, it is also this population who has the lowest adherence rates to the full course of vaccination.”

“The data from this pivotal Phase 3 study have meaningful public health importance, demonstrating the ability of the 3-antigen HBV vaccine candidate to elicit high rates of seroprotection and increased antibody titers after both two and three doses in this population compared to the conventional, single-antigen HBV vaccine.”

“Moreover, these data add to the well-established safety profile of this vaccine.”

Hepatitis B is a vaccine-preventable liver infection caused by the hepatitis B virus, says the U.S. CDC.

Hepatitis B is spread when blood, semen, or other body fluids from a person infected with the virus enters the body of someone who is not infected. This can happen through sexual contact, sharing needles, syringes, or other drug-injection equipment, or from mother to baby at birth.

Not all people newly infected with HBV have symptoms, but symptoms can include fatigue, poor appetite, stomach pain, nausea, and jaundice for those who do.

For many people, hepatitis B is a short-term illness.

For others, it can become a long-term, chronic infection that can lead to serious, even life-threatening health issues like cirrhosis or liver cancer.

The risk for chronic infection is related to age at infection: about 90% of infants with hepatitis B develop chronic infection, whereas only 2%–6% of people who get hepatitis B as adults become chronically infected.

The best way to prevent hepatitis B is to get vaccinated, says the CDC.

Various HBV vaccines are listed on this webpage.

PrecisionVaccination publishes fact-checked research-based vaccine news.

Sub Title:

VBI’s 3-antigen hepatitis B vaccine is comprised of the S, pre-S1, and pre-S2 surface antigens of the HBV

References:

Immunogenicity and Safety of a 3-Antigen Hepatitis B Vaccine vs a Single-Antigen Hepatitis B Vaccine

Engerix-B Hepatitis B Vaccine

Sci-B-Vac Hepatitis B Vaccine

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Google News Keywords:

health, vaccines, vaccinations, hepatitis b, hep b, hvb, liver disease, sex and hep b

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Fact checked:

Tuesday, October 19, 2021 - 05:45