Prior to implementing universal childhood vaccination in Alaska, rates of hepatitis A in Alaska Native persons were more than five times higher than those in other racial/ethnic populations.[2] Further data are needed to determine the possible requirement of hepatitis A vaccine booster doses to ensure continued protection. Hepatitis B virus (HBV) can cause chronic infection, resulting in cirrhosis of the liver, liver cancer, liver failure, and death.[4] [5] Much like the hepatitis A vaccine, hepatitis B immunization strategies for infants, children, adolescents and adults have significantly decreased the incidence and prevalence of acute and chronic hepatitis B infection.[6] The complete duration of protection after primary vaccination with hepatitis B vaccine and thus whether booster doses of vaccine to maintain protection against HBV infection are required is undetermined. There is elevated importance for persons who initiated hepatitis B vaccination at birth. Recent data, including that from the Alaska Native Tribal Health Consortium, Liver Disease and Hepatitis Program research team, suggest an increased proportion of persons vaccinated as newborns lose protective antibody compared with those vaccinated as children or adults.[7, 8] Prior to hepatitis B vaccination, prevalence of hepatitis B infection amongst Alaska Native persons was endemic.[9] Although hepatitis B incidence has declined dramatically since implementation of vaccination among Alaska Native infants, children and adults, there remain a substantial number of Alaska Native persons chronically infected with HBV and remain at an increased risk of disease sequelae including hepatocellular carcinoma.[10] Alaska Native persons chronically infected with HBV also exhibited increased incidence of hepatocellular carcinoma amongst younger people.[11] In addition to chronic HBV, other chronic liver disease etiologies including chronic hepatitis C, non- alcoholic fatty liver disease and autoimmune hepatitis have been shown to cause substantial morbidity and mortality among Alaska Native persons.[12] [13] Further complication in the clinical management of chronic hepatitis B and C in Alaska is due to the remoteness of the population and the lack of access to specialty care. New diagnostic tests are needed that are less invasive, more sensitive and do not require specialty clinical service. We propose to address these public health issues by determining the further duration of vaccine protection afforded by both hepatitis A and hepatitis B vaccines in children and adults in well-established longitudinal cohorts. We also intend to measure the effectiveness and impact of clinical interventions on mortality and morbidity associated with chronic hepatitis B and chronic hepatitis C including screening, early diagnostics and treatment. To safely delay the need for booster doses of either hepatitis A or hepatitis B vaccines can result in both safety from exposure to these viruses and healthcare cost savings. Understanding the influence of clinical interventions can provide new diagnostic tools for chronic viral hepatitis outcome as well as new clinical management strategies that could be useful to apply in a variety of healthcare settings.

Public Health Relevance

To safely delay the need for booster doses for hepatitis A and B vaccines further data are required to confirm long-term protection afforded by vaccination. In addition, better understanding of the influence clinical interventions and factors have on chronic hepatitis B and C infection can provide new diagnostic tools that may improve disease outcome. Management strategies developed under this proposal for vaccine policy and chronic HBV and HCV clinical management can be applied to managed care settings in the US and in regions where health care access is limited.

Agency
National Institute of Health (NIH)
Institute
National Center for HIV, Viral Hepatitis, STDS and Tb Prevention (NCHHSTP)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01PS004113-04
Application #
9071855
Study Section
Special Emphasis Panel (ZPS1)
Program Officer
Smutz, Paul
Project Start
2013-07-01
Project End
2018-06-30
Budget Start
2016-07-01
Budget End
2017-06-30
Support Year
4
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Alaska Native Tribal Health Consortium
Department
Type
DUNS #
071375658
City
Anchorage
State
AK
Country
United States
Zip Code
99508
Bruden, Dana J T; McMahon, Brian J; Townshend-Bulson, Lisa et al. (2017) Risk of end-stage liver disease, hepatocellular carcinoma, and liver-related death by fibrosis stage in the hepatitis C Alaska Cohort. Hepatology 66:37-45
Connelly, Marc; Bruce, Michael G; Bulkow, Lisa et al. (2016) The changing epidemiology and aetiology of hepatocellular carcinoma from 1969 through 2013 in Alaska Native people. Liver Int 36:1829-1835
Ching, Lance K; Gounder, Prabhu P; Bulkow, Lisa et al. (2016) Incidence of hepatocellular carcinoma according to hepatitis B virus genotype in Alaska Native people. Liver Int 36:1507-15
Gounder, Prabhu P; Bulkow, Lisa R; Snowball, Mary et al. (2016) Hepatocellular Carcinoma Risk in Alaska Native Children and Young Adults with Hepatitis B Virus: Retrospective Cohort Analysis. J Pediatr 178:206-213
Gounder, P P; Bulkow, L R; Snowball, M et al. (2016) Nested case-control study: hepatocellular carcinoma risk after hepatitis B surface antigen seroclearance. Aliment Pharmacol Ther 43:1197-207
Livingston, Stephen E; Townshend-Bulson, Lisa J; Bruden, Dana J T et al. (2016) Results of interferon-based treatments in Alaska Native and American Indian population with chronic hepatitis C. Int J Circumpolar Health 75:30696