Understanding If There’s a Cure for Hepatitis B

When news broke in 2014 that hepatitis C, a viral disease affecting the liver, could be cured thanks to a new class of direct-acting antiviral drugs, many began to wonder how soon it would be before the same occurred with its cousin, hepatitis B.

Scientists have yet to find a cure for this potentially severe form of viral hepatitis, which affects anywhere from 2.4 million to 4.7 million people in the United States.

This article takes a look at hepatitis B and ongoing cure research, including the development of direct-acting antivirals similar to those used to treat hepatitis C. It also explains how hepatitis B is currently treated and prevented with medications and vaccines.

Is There a Cure for Hepatitis B?

The long and short answer is that there is not yet a cure for hepatitis B. Understanding why requires insight into the virus itself and the challenges cure researchers face.

Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV). While most people exposed to hepatitis B will spontaneously clear the virus (eliminating it from the body) soon after infection, a proportion will go on to develop a chronic (persistent) infection.

Of these, around one in four will develop severe liver complications, including cirrhosis (extensive scarring of the liver) and liver cancer, typically years after the initial infection.

Efforts to find a cure for hepatitis B have been underway since the virus was first identified by scientists at the National Institutes of Health in 1966. It soon became clear, however, that numerous hurdles would need to be overcome before an actual cure could be achieved. Chief among these are:

• Poor innate immunity: For reasons that are not entirely clear, HBV is not readily recognized by the immune system during early-stage infection and is poorly eliminated by the body's frontline innate immune response.
  
• Poor adaptive immunity: Over time, the body's disease-specific adaptive immune response also weakens due to a phenomenon known as T-cell exhaustion. When this occurs, the immune system is less able to recognize and launch an immune assault against the virus.
• Viral reservoirs: In chronically infected people, HBV will embed itself within tissues inside and outside the liver, called viral reservoirs. Within these reservoirs, the virus is largely shielded from immune detection and is difficult to reach with antiviral drugs.
• cccDNA: What differentiates hepatitis B from hepatitis C is the unique structure of its viral DNA, called covalently closed circular DNA (cccDNA). Antiviral drugs have limited effectiveness against this seemingly indestructible "mini-chromosome" that continues to pump out new viruses from infected liver cells.

Overcoming the Hurdles

Despite the challenges in finding a cure, scientists have a greater understanding of how HBV infects, replicates, and persists. By targeting and blocking these mechanisms with either one or a combination of therapies, scientists hope to one day render the virus harmless or eliminate it.

Among some of the leading drug candidates are:

• Bepirovirsen: An experimental direct-acting antiviral that may block cccDNA from delivering the genetic code used to build new viruses
• HBsAg monoclonal antibody: An experimental form of immunotherapy used to boost the immune system's ability to recognize and launch a targeted immune attack against HBV
• JNJ-64300535: An experimental therapeutic vaccine that may help activate the adaptive immune response in people with chronic hepatitis B infection
• REP 2139/2165: An experimental antiviral direct-acting antiviral that appears to improve the immune system's ability to control the virus
• RO7049389: An experimental direct-acting antiviral that blocks the assembly of new viruses

Difference Between Acute and Chronic Hepatitis B

Acute hepatitis B is the stage of infection immediately following exposure to the virus. Many of these infections are asymptomatic, meaning without symptoms.

Of those who do develop symptoms, some of the more common include:

• Fever
• Persistent fatigue
• Loss of appetite
• Nausea or vomiting
• Abdominal pain
• Dark urine
• Clay-colored stools
• Jaundice (yellowing of the skin and the whites of the eyes)

Chronic hepatitis B occurs when the immune system does not clear the virus. Around one of every 20 people acutely infected with HBV will progress to this persistent stage of infection.

Chronic hepatitis B is a slowly progressive disease in which ongoing inflammation causes the gradual scarring of the liver. This can lead to cirrhosis (the loss of liver function due to scarring) and hepatocellular carcinoma (the most common form of liver cancer).

However, the course of chronic HBV infection is not set. Some people may progress faster than others, while others may never develop overt symptoms.

Statistically speaking:

• The risk of cirrhosis in people with chronic hepatitis B is approximately 10% to 20% over 20 years, increasing to 40% after 30 years.
• The risk of hepatocellular carcinoma increases by 2% and 3% per year in people with HBV and cirrhosis. People without cirrhosis can also get it, but the annual risk drops to around 0.02%.
  

How Hepatitis B Is Treated

Hepatitis B cannot be cured, but newer, less toxic drug therapies have effectively slowed the progression of the disease in chronically infected people. Even those with advanced liver disease have longer survival and better quality of life thanks to newer drug therapies.

Acute Hepatitis B

There is no specific treatment for acute hepatitis B infection. If you experience acute symptoms of hepatitis B and test positive for the virus, the treatment would be focused on managing symptoms and providing nutritional support.

An exception is in people with fulminant hepatitis, an uncommon but severe form of liver failure that typically occurs within eight weeks of the appearance of hepatitis symptoms.

Fulminant hepatitis is treated with the antiviral drug Epivir (lamivudine) to reduce the risk of liver damage and the need for a liver transplant. Epivir may also be considered in people with acute hepatitis B who experience severe symptoms.

There are no drugs able to clear an HBV infection after it occurs.

With that said, many people with acute hepatitis will spontaneously clear the virus and, in turn, be afforded lifelong immunity to HBV.

Chronic Hepatitis B

Chronic hepatitis B is definitively diagnosed when blood tests are able to detect a protein called hepatitis B surface antigen (HBsAg). lt can take up to six months to accurately detect HBsAg after an infection occurs.

Most people with chronic hepatitis B require treatment for a lifetime to slow the progression of the disease. This may involve:

• Antiviral drugs: These medications are taken by mouth every day and work in different ways to block the replication of HBV. The six options approved for use in the United States are Baraclude (entecavir), Epivir (lamivudine), Hepsera (adefovir), Tyzeka (telbivudine), Vemlidy (tenofovir AF), and Viread (tenofovir DF).
• Pegasys (pegylated interferon alfa-2A): This drug is injected subcutaneously (under the skin) that interferes with the replication of HBV. It also enhances the immune response to the virus. It is typically used as part of combination antiviral therapy.
• Liver transplantation: This is an option if you experience liver failure or liver cancer. The organ usually comes from a deceased donor. Less commonly, a portion of a living donor's liver can be transplanted.

Is Hepatitis B Preventable?

Chronic hepatitis B infection affects at least 250 million people worldwide, causing over 880,000 deaths annually. It is also the major cause of liver cancer, the second leading cause of cancer-related deaths in the United States.

Unlike its cousin hepatitis C, hepatitis B can be prevented with vaccines. If you are accidentally exposed to the virus, there are also drug therapies you can take—called postexposure prophylaxis—to avert the infection.

Hepatitis B Vaccine

The three hepatitis B vaccines approved for use by the Food and Drug Administration (FDA) are:

• Engerix B
• Heplisav-B
• Recombivax HB

The vaccines are given by injection into a large muscle in either two or three doses over six months. The dosage varies by the person's age, immune status, and choice of vaccine.

Postexposure Prophylaxis

Postexposure prophylaxis (PEP) is a treatment designed to prevent an infection after a recent exposure. For hepatitis B, PEP may involve:

• Hepatitis B vaccination (or revaccination): A three-dose vaccine series typically is advised.
• Hepatitis B immunoglobulins (HBIG): This is a purified solution of hepatitis antibodies derived from donated blood. It is delivered by injection to bolster the body's natural immune defenses.

Hepatitis B vaccination is considered the mainstay of PEP. In cases in which the source of the exposure is known to have hepatitis B, both hepatitis B vaccination and HBIG would be used.

Hepatitis B PEP should ideally be started within 24 hours of the suspected exposure, although it may still have benefits up to seven days after the exposure.

How Do You Get Hepatitis B?

The hepatitis B virus is found mainly in the blood but also in semen and vaginal secretions.

The virus is passed when body fluids from someone with hepatitis B enter the body of someone without hepatitis B. This can happen when sharing needles or syringes, engaging in vaginal or anal sex, or during childbirth, when the virus can be passed from mother to baby.

While vaccination remains the cornerstone of HBV prevention, there are ways to further reduce the risk of transmission, especially if you or someone in your household has hepatitis B:

• Wash your hands with soap and water if exposed to blood.
• Avoid sharing razors or toothbrushes.
• Use condoms during sex.
  
• Cover all cuts carefully.
• Discard tampons and sanitary napkins into individual plastic bags.
• Avoid sharing needles, syringes, or other drug paraphernalia.
• Only used licensed tattoo or body piercing studios.
• Be sure that new, sterile needles are used for acupuncture.

Summary

Hepatitis B can be treated and prevented, but it cannot be cured. Research is underway to investigate different drugs and drug combinations that may one day offer cure rates similar to those seen with hepatitis C.

Until then, it is important to seek treatment if you are diagnosed with chronic hepatitis B. Doing so can slow the progression of the disease and reduce the risk of cirrhosis, liver failure, or liver cancer.

Hepatitis B vaccination is recommended for children and all people at risk of getting hepatitis B.

A Word From Verywell

Until scientists find a safe and effective cure for hepatitis B, you need to focus on protecting yourself and others from this potentially serious viral infection. Hepatitis B vaccination is central to this, offering protection of between 98% and 100%.

If you are unsure whether you've ever been vaccinated against hepatitis B, speak with your healthcare provider. If you're still unsure, consider undergoing the two- to three-dose series just to be safe, especially if you are at risk of infection.

The three approved hepatitis B vaccines are regarded as safe and effective. Side effects tend to be mild and may include headache, fever, and injection site soreness or redness.