A hepatitis B vaccine booster dose 30 years after vaccination is not necessary, according to results of a study published online January 21 in the Journal of Infectious Diseases.
Universal vaccination with hepatitis B vaccine has been very effective on a global scale, but protection has only been assessed for 22 years.
Michael G. Bruce, MD, MPH, from the Arctic Investigations Program at the Centers for Disease Control and Prevention, Anchorage, Alaska, and colleagues tracked protection among 1578 Alaska Native adults and children aged 6 months or older who each received three doses of the plasma-derived hepatitis B vaccine shortly after it became available in 1981. Researchers assessed response with annual hepatitis B virus serological testing for the first 11 years and then at 15 and 22 years after the first dose. After 22 years, 60% of the participants had a protective level of antibodies, and if booster response is considered, 93% were protected, with no new infections.
The new results from the long-term prospective cohort study assessed 435 (56%) of 783 eligible participants from the original group. Primary outcomes were the percentage of individuals whose anti–hepatitis B surface antigen (HBs) levels exceed 10 mIU/mL (the cutoff for protection), immune response to a booster dose among those with anti-HBs lower than 10 mIU/mL, and comparison of characteristics of participants with or without protective antibody levels. The booster was administered 2 to 4 weeks after the 30-year assessment and evaluated 30 days later.
At its outset, the study enrolled individuals from 15 communities, but administered booster doses for applicable participants at 22 years for only seven communities. This left eight communities "naive" for the 30-year assessment of immunogenicity of the vaccine.
The researchers evaluated the participants at 30 years according to three groups: group 1 (n = 243) had not been part of the 22-year study. Group 2 had anti-HBs levels too high to require booster doses at 22 years (n = 129). Group 3 (n = 63) received boosters at 22 years. Analysis of antibody response at 30 years used group 1 data alone. For analysis of response to booster doses, groups 1 and 2 were used. For group 3, the study presents only data on immunogenicity 8 years after the booster dose.
Among the 243 individuals who responded to the original vaccine and had no boosters, at 30 years, 125 (51%) had anti-HBs levels of 10 mIU/mL or higher. Among participants with anti-HBs levels lower than 10 mIU/mL, 75 (88%) of 85 responded to booster doses with anti-HBs levels of 10 mIU/mL or higher at 30 days. In addition, beginning anti-HBs levels after receiving vaccine correlated positively to higher antibody levels at 30 years.
"Based on anti-HBs level ≥10 mIU/mL at 30 years and an 88% booster dose response, we estimate that ≥90% of participants had evidence of protection 30 years later. Booster doses are not needed," the researchers conclude. Their findings are similar to those from Gambia, Taiwan, Thailand, and elsewhere.
The researchers add that children vaccinated through catch-up programs or young adults vaccinated for occupational safety reasons are likely to be protected for decades. The findings are also highly relevant for healthcare workers because of their elevated risk for infection and the cost of periodic screening. "Our study provides strong evidence to support the [Centers for Disease Control and Prevention] recommendation that protection, after a complete series of hepatitis B vaccine and documentation of the initial response, will last for ≥30 years," the investigators write.
A limitation of the study is that the initial vaccine was plasma-derived and the booster was recombinant.
In an accompanying editorial commentary, Pierre Van Damme, MD, PhD, from the Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute at the University of Antwerp, traces the history of hepatitis B vaccination from availability in 1982 to introduction of the recombinant vaccine, to efforts to fill vaccine gaps starting in 1992. By the end of 2014, 184 countries included the vaccine in national childhood immunization programs, with global coverage at 82%, according to the World Health Organization.
"The data presented by Bruce et al confirm statements from the World Health Organization, Centers for Disease Control and Prevention, and Viral Hepatitis Prevention Board that booster vaccination against hepatitis B for immunocompetent children and adults is not recommended," Dr Van Damme writes. He calls for further investigation of the anamnestic response and continuing long-term follow-up to track duration of immune memory and identify circumstances under which boosters may be needed to maintain protection.
The researchers and commentator have disclosed no relevant financial relationships.
J Infect Dis. Published online January 21, 2016. Article full text, Van Damme full text
Medscape Medical News © 2016 WebMD, LLC
Send comments and news tips to news@medscape.net.
Cite this: Hepatitis B Vaccine Booster Unnecessary - Medscape - Jan 27, 2016.
Comments