Hepatitis B Vaccine

Mechanism of Action

The vaccine is a non-infectious subunit of the virus, which leads to an active immunity. Antibodies produced by vaccination target the outer protein coat or surface antigen. This leads to protection against all genotypes (A through H) of the virus and gives a broad immunity.[4]

It is generally accepted that the hepatitis B vaccine confers lifelong protection; originally, it was thought to only last around eight years, but more recent research has confirmed ongoing immunity for at least 25 years in those individuals who demonstrated a good immune response from the vaccine series.[5][6] 

Patients who fail to develop a good response from the vaccine tend to be over 40 years of age, obese, have celiac disease, smoke tobacco, or misuse alcohol. This last group will especially be affected if they have progressed to liver disease.[7][8] 

Administration

Intramuscular injection is the preferred administration method. The intradermal route is not recommended. The preferred site of injection is the deltoid muscle. A regimen of three doses of the recombinant vaccine over six months is the current preferred method. A new vaccine has received approval for adults in the United States, which requires just two doses in one month.[1][4]

After completing the three vaccination series, patients may receive a blood test after one to four months to determine the immune response, which is defined as an anti-hepatitis B surface antigen (anti-Hbs) antibody level exceeding 100mIU/mL. An antibody response falling between 10 and 100 mIU/mL demonstrates an inadequate response; these patients should get a single booster shot, but do not require a retest. Responses below 10 mIU/mL require additional testing to check for prior hepatitis B infection, and these patients should receive another three-dose regimen with testing again at the one to four-month mark. Continued failed response warrants may require more aggressive interventions, including intradermal administration, high-dose vaccine, or double dosing of combination hepatitis A and hepatitis B vaccine. Should this fail, the patient will need hepatitis B immunoglobulin upon any exposure to the hepatitis B virus.[8][9][10]

Adverse Effects

Research has demonstrated the hepatitis B vaccine to be safe for all age groups.[11] From 1982 to 2004, over 70 million persons received at least one dose of the vaccine in the United States, with the most reported side effects being: injection site pain (3 to 29%) and temperature greater than 99.9°F (1 to 6%).[12] These effects occurred at similar rates with persons receiving a placebo.[12] However, the Institute of Medicine in 2011 did conclude that evidence supports a causal relationship between the vaccine and anaphylaxis in persons with hypersensitivity to yeast.[12]

Contraindications

Hepatitis B vaccine is contraindicated in individuals with a history of hypersensitivity to any components of the vaccine or a yeast hypersensitivity.[12][11] Therefore, persons with a history of serious adverse events, such as anaphylaxis, after a previous hepatitis B vaccination (including combination vaccines) should not receive any further doses. Of note, the vaccine is not contraindicated in persons with a history of Guillain-Barre syndrome, autoimmune disease, current pregnancy, or lactation. The vaccine contains a noninfectious surface antigen, which poses no risk of transmission to the fetus.[11]

Monitoring

Hepatitis B surface antibody titers increase quickly following vaccination and then decrease over time.[1] More than 90% of immunized children develop protective antibody levels after the first dose.[12][13] An immunocompetent person receiving the complete series is generally protected indefinitely. The Advisory Committee on Immunization Practices (ACIP) does not generally recommend titers after vaccination, except for some health care workers and immunocompromised persons.[1] In health care workers at risk for occupational exposure, serologic testing is recommended 1 to 2 months after the last vaccine dose, and revaccination with ≥one dose is the recommendation for non-responders.[14][13] 

Health care workers who completed the vaccine series and had a subsequent positive titer (≥10 mIU/mL anti-HBs) are considered hepatitis B immune and do not need any further routine testing for protection so long as they remain immune-competent.[14] All persons receiving the vaccine should remain under observation for at least 15 minutes following its administration for syncope or signs of anaphylaxis.[4][12][11]

Toxicity

The vaccine is not known to have any dose-dependent toxicity, especially with newer nanoparticle formulations.[7] There is no antidote indicated for its management.

Enhancing Healthcare Team Outcomes

The interprofessional health care team faces many challenges when vaccinating patients for hepatitis B. While few medical interventions have as significant an impact on health as vaccinations, and the hepatitis B vaccination is generally safe, lack of knowledge about the vaccine by healthcare team members and patient concern about adverse events can decrease coverage. Challenges on knowledge of the vaccine for healthcare team members include staying current on evolving recommendations for whom the vaccine is indicated.[1][12][15] All team members can increase the vaccination rate of their patients by encouraging all staff to become trained in the assessment of vaccination histories and any pertinent staff in the administration of the vaccine. Protecting the time available for the team to do this is an essential component of this strategy. All patients should receive education on the benefits of vaccination, including its herd immunity effect, the generally safe side effect profile, and the relatively few contraindications. A presumption of acceptance may be effective with most patients.[1][15] The hesitant parent and patient who does not respond to this can pose a challenge in vaccination.[15] Motivational interviewing techniques have shown to be effective with these hesitant patients.[1]

Nurses should always verify the patient's vaccination status regarding hepatitis B (as well as other vaccines) and report their findings to the clinician. Many states in the USA allow pharmacists to administer the vaccine, and pharmacists should reinforce the counsel from the provider and nursing staff and update the patient's record with each dose. In this manner, the entire interprofessional team can operate from the same data regarding vaccination status, leading to better patient outcomes. [Level 5]

Of note, there is a new adjuvanted vaccination in development, now approved for adults in the United States for adults, which would reduce the time for series completion from a six-month 3-dose series to a one-month 2-dose series.[1][16][17] This development would carry the promise to reduce some of the burdens on patients, physician offices, and pharmacies of administering the vaccine series as well as increase vaccination rates.[1][16][17]