Technically Speaking: The Hepatitis B Midlife Crisis

True or false?
All adults through 59 years of age are recommended to get hepatitis B vaccine.

Recent changes to hepatitis B vaccine recommendations make the answer to this statement true. Due to these updates, and since May is Hepatitis Awareness Month, this month’s “Technically Speaking” column focuses on U.S. hepatitis B vaccination policies and rationale.

Hepatitis B: The virus

Hepatitis B virus (HBV) is old. According to an evolutionary biology team at Uppsala University, evidence of HBV’s genome exists in zebra finch ancestors dating from the Mesozoic Era (the age of the dinosaurs). They wrote, “Our study provides direct evidence that the compact genomic organisation of Hepadnaviridae has remained largely unchanged for the last > 82 [million years] of hepadnaviral evolution.”

HBV is a DNA virus that replicates by forming stable, closed circular minichromosomes in the nuclei of liver cells. Its unique genomic structure is thought to aid in the ability of HBV to persist indefinitely for some, leading to the silent chronic infection that characterizes this infection. Indeed, while short-term acute HBV disease is not greatly feared, chronic hepatitis B disease, which leads to cirrhosis and primary liver cancer, is a worldwide problem.

Each year, about 1.5 million new HBV infections occur. Using the most recent global data (2019), the World Health Organization (WHO) estimated that 296 million people are living with chronic hepatitis B infection — this means about 1 of every 26 people throughout the world carry this virus and can spread it to others. Further, they estimated that in 2019, hepatitis B infection resulted in about 820,000 deaths.

In the U.S. between 2015-2018, about 4.3% of individuals were estimated to have previous or current HBV infections, with higher rates based on gender, race and birth country:

• Men are more likely than women to be infected (5.3% versus 3.4%, respectively).
• People of non-Hispanic Asian origin are most likely to be infected (21.1%), followed by those who are non-Hispanic Black (10.8%), Hispanic (3.8%), or non-Hispanic White (2.1%).
• People born outside of the U.S. are more likely to be infected than those born in the U.S. (11.9% versus 2.5%, respectively).

Hepatitis B: The vaccine

The first hepatitis B vaccine was licensed in 1981. It was made by isolating and inactivating hepatitis B virus from the plasma of HBV-infected donors. However, the idea of using the blood of infected individuals as the source of the vaccine, particularly as scientists worked to understand the cause of AIDS, led to theoretical safety concerns and poor acceptance. As such, a second version, which is still used today, became available in 1986. It relied on a new technology, called recombinant DNA technology.

• Watch this clip from HILLEMAN: A Perilous Quest to Save the World’s Children to hear more about how both of these vaccines were made and the “firsts” each represented.

The hepatitis B vaccine was recommended for all infants in 1991. While some parents have wondered why infants are vaccinated against an infection that is commonly perceived as sexually transmitted, we should collectively work to ensure that they understand three important points:

1. Until they develop liver disease or liver cancer, many people with chronic infections don’t know they are infected. As a result, they may not take precautions against spreading it.
2. Transmission can occur following exposure to quantities of infected blood so minimal that they cannot be seen with the naked eye.
3. When children are infected, they are more likely to develop chronic infection and they often do not develop symptoms, so their infection may go undetected.

Hepatitis B: Rationale for universal adult vaccination

A person born the day the routine infant vaccination recommendation was published is 40 years old today. When looking at the rates of infection among those who were probably not vaccinated during infancy, data showed that:

• Individuals between 40-49 years of age were more likely to be diagnosed with an acute hepatitis B infection over time. Rates rose from 1.9 per 100,000 people in 2011 to 2.7 per 100,000 people in 2019.
• Those between 50-59 years of age were also more likely to be infected during this period. Rates among this group rose from 1.1 to 1.6 per 100,000 people.
• In 2018, 31.7% of the reported cases of acute hepatitis B were in adults 40-49 years of age, and almost two-thirds of all reported cases were in adults 40 or older.
• Although conversion from acute infection to chronic disease occurs less frequently among adults than children, an estimated 2% to 6% of adult cases become chronic.

For these reasons, the ACIP voted to expand the recommendation for hepatitis B vaccination of adults. The new recommendation was published in the MMWR on April 1, 2022:

HepB vaccination is recommended for adults aged 19-59 years and adults aged ≥ 60 years with risk factors for hepatitis B. Adults aged ≥ 60 years without known risk factors for hepatitis B may also receive HepB vaccines … Infants and all other persons aged < 19 years are already recommended to receive HepB vaccines.

To see a list of hepatitis B risk factors relevant in vaccination decisions for adults 60 years of age and older, please refer to the MMWR article.

If your practice has not already incorporated routine hepatitis B vaccination of adults to your workflow, Hepatitis Awareness Month is a great time to do so. By working together, we can ensure that all unvaccinated, or incompletely vaccinated, adults learn of this recommendation and receive the hepatitis B vaccine. Whether you use standing orders, provider prompts or a hybrid of these approaches, the screening process for hepatitis B vaccination has gotten a whole lot easier and as such, much more feasible.

Hepatitis B: Resources

As you prepare to incorporate hepatitis B vaccination into your workflows, and conversations about hepatitis B vaccine increase, these tools may be helpful for you and your team:

Vaccine Education Center

• A look at each vaccine: Hepatitis B (webpage)
• Hepatitis B: What you should know (Q&A; will be updated soon!) English | Spanish | Japanese
• Hepatitis-related video playlist — Check out the hepatitis-related videos to use alone or share the entire playlist.

Immunize.org

• Ask the Experts: Hepatitis B (webpage)
• Standing orders templates
  • Hepatitis B vaccine (HepB) — children and teens
  • Hepatitis B vaccine (HepB) — adults
• Hepatitis B Vaccine Information Statement (with 12 up-to-date translations)
• Handouts: Hepatitis B (webpage)

Books available at no charge

• The Vaccine Handbook App
• The Epidemiology and Prevention of Vaccine Preventable Diseases (“The Pink Book”)