Hepatitis vaccine booster

hepatitis vaccine booster

In 2009, 3,374 cases of acute Hepatitis B in the United States were reported to CDC; the overall incidence of reported acute Hepatitis B was 1.5 per 100,000 population, the lowest ever recorded. However, because many HBV infections are either asymptomatic or never reported, the actual number of new infections is estimated to be approximately tenfold higher. In 2009, an estimated 38,000 persons in the United States were newly infected with HBV. Rates are highest among adults, particularly males aged 25–44 years.
An estimated 800,000–1.4 million persons in the United States have chronic HBV infection. Chronic infection is an even greater problem globally, affecting approximately 350 million persons. An estimated 620,000 persons worldwide die from HBV-related liver disease each year.

Transmission of Hepatitis B

HBV is transmitted through activities that involve percutaneous (i.e., puncture through the skin) or mucosal contact with infectious blood or body fluids (e.g., semen, saliva), including

• Sex with an infected partner
• Injection drug use that involves sharing needles, syringes, or drug-preparation equipment
• Birth to an infected mother
• Contact with blood or open sores of an infected person
• Needle sticks or sharp instrument exposures
• Sharing items such as razors or toothbrushes with an infected person

HBV is not spread through food or water, sharing eating utensils, breastfeeding, hugging, kissing, hand holding, coughing, or sneezing

The Need for a Booster Dose

After several decades of vaccination against hepatitis B virus in newborns, infants, adolescents, and adults, the question remains whether a booster dose is ever needed. Long-term protection is most commonly measured through 4 methods: the anamnestic response after administration of a booster dose, infection rate in vaccinated populations, in vitro B and T cell activity testing, and seroepidemiological studies. Long-term protection is present despite a decrease in anti-hepatitis B surface antibodies over time. The exact mechanism of long-term protection, however, is not yet fully understood. There is no need for boosters in immunologically potent persons as long as a full course was adequately administered that respected the recommended timelines, as evidenced by studies conducted up to 20 years after the original immunization course. However, a booster dose should be planned for immunocompromised patients, based on serological monitoring.

The question that remains to be answered is how long immune memory will last. Early evidence suggests that the answer will come from the power of the initial immune response and from the time since primary vaccination. Long-term follow-up studies during the third decade after vaccination administration are needed to confirm the duration and persistence of immune memory. In addition, studies that follow-up birth cohorts vaccinated >20 years ago are needed as those individuals become sexually active and potentially exposed to HBV infection.

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