Study shows universal vaccination has wiped out hepatitis B and associated liver cancer in Alaska's young people.
Updated research presented at this year's World Indigenous Peoples' Conference on Viral Hepatitis in Anchorage, Alaska, USA (8-9 August) shows that the universal hepatitis B vaccination programme introduced for all newborn Alaskan children in the 1980s has wiped out hepatitis B infection and liver cancer cases associated with the infection. The study is by Dr Brian McMahon, Director of the Alaska Native Tribal Health Consortium (ANTHC) Hepatitis Program, Anchorage, AK, USA and colleagues at ANTHC including Dr Rosalyn Singleton.
Hepatitis B is a serious liver infection, which, if left untreated, becomes chronic, leading to extensive liver damage, liver cancer, and death. Since Hepatitis B is highly contagious, it spread rapidly in rural villages especially among young children.
In the 1970s and 1980s, Alaska Native (AN) people residing in Alaska experienced the highest rates of acute and chronic hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC - liver cancer) in the USA. In 1981-82, a HBV vaccine demonstration project providing HBV screening and vaccination was conducted in 2 highly endemic regions of Alaska. In 1984, the program was extended to AN people statewide, and AN infants in tribal health facilities were offered 3 doses of hepatitis B vaccine starting at birth. At the same time, a vaccine catch-up program was conducted in schools statewide and also included reminders for AN adults that had tested negative for the virus.
The authors of this updated research used data from the surveillance system set up in 1981 in tribal health facilities to detect acute HBV infections. Cases of HCC in young people aged 20 years and younger were identified using the US National Cancer Institute/CDC-funded cancer registry in place since 1969, combined with an active surveillance program screening those already known to be infected with HBV since 1982. Estimated vaccine coverage with 3 doses of hepatitis B vaccine among AN children living in Alaska was reported by the National Immunization Survey (NIS).
The data collected show that routine infant hepatitis B vaccination and mass screening have resulted in high levels of vaccine coverage in Alaskan AN children 1935 months of age. The 1996 NIS estimated 3 dose hepatitis B vaccine coverage was higher among Alaskan AN children (94%) than the general U.S. population (82%), regardless of race. From 1996 to 2008, NISreported vaccine coverage among Alaska AN children has remained at a high level (87-99%).
The incidence of acute symptomatic HBV infection in AN persons aged 20 years and under decreased from 19 per 100,000 in 19811982 to no reported cases since 1992. The incidence of HCC in AN persons aged under 20 years decreased from 3 per 100,000 in 19841988 to no reported cases since 1998. The number of chronically infected HBV AN patients aged 20 years and under decreased from 657 in 1988 to just two cases in total since 1999, the last of those identified in 2010.
The authors say: "Universal newborn vaccination coupled with mass screening and immunisation of susceptible AN people has eliminated early onset HCC and acute symptomatic HBV infection as a public health threat among AN children. This population based approach can serve as a model for other populations."
They conclude: "The elements of this program that we introduced - which include screening and interventions to reduce perinatal transmission and universal vaccination- are recommended as the standard of care for all US populations, including Indigenous populations. Elimination in other populations, however, depends on the how effectively those interventions are applied, which might not be as comprehensive as took place in the AN tribal system."
Hepatitis A vaccination for Alaskan children has wiped out the virus.
A comprehensive hepatitis A vaccination program established in Alaska in the 1990s, which became a requirement for school entry in 2001, has virtually wiped out the virus in the native peoples of Alaska, where it had been endemic.
Data from the program was presented at this year's World Indigenous Peoples' Conference on Viral Hepatitis in Anchorage, Alaska, USA (8-9 August) by Stephanie Massay, Epidemiology Specialist with the Alaska Division of Public Health, Section of Epidemiology, Anchorage, AK, USA, and colleagues.
Hepatitis A is an acute (short-term but severe) infection of the liver caused by the hepatitis A virus. Fever, weakness, nausea, aches and pains, and jaundice can be among the symptoms experienced. The hepatitis A virus can survive in the environment on and in food. It is also relatively resistant to detergents but can be inactivated by high temperature (85°C or higher) and by chemicals such as chlorine. Although it occurs worldwide, HAV occurs more commonly in populations with poor sanitation, such as poor populations in developed countries (e.g. Indigenous populations) and also in developing countries more generally.
Alaska experienced epidemics of hepatitis A every 10-15 years during the 1950s to the 1990s, resulting in thousands of cases. Alaska Native (AN) people living in rural communities were disproportionately impacted.
Hepatitis A virus (HAV) vaccines were licensed in 1995 and recommended by the Advisory Committee on Immunization Practice (ACIP) for routine vaccination of US children in populations with high HAV infection rates. Alaska began universal vaccination for children aged 2-14 years in 1996? HAV vaccination became required for school entrance in 2001. In 1997, following ACIP recommendations, this was expanded to include all children age 2 - 18 years, and in 2006 this was further expanded to include children age 1 - 18 years.
The data showed that during 1972-1995, Alaska's average annual incidence of hepatitis A was 60 per 100,000 population. Rates by race were substantially higher for AN people compared to non-AN people (244 vs 19 per 100,000 respectively, with AN people being 13 times more likely to be infected than non-AN people).
Compared to 1972-1995 (pre-vaccine), 2002-2007 (postvaccine) statewide hepatitis A incidence fell by 98% (0.9 vs. 60 per 100,000); among AN peoples the incidence fell by 99.9% (0.3 vs. 243.8 per 100,000). During 2008-2016, 23 HAV cases were reported in Alaska? 5 among AN, 11 among nonAN, and 7 among people of unknown race/ethnicity.
The 2008-2016 statewide incidence of hepatitis A was 0.35 cases per 100,000 people? the incidence in children aged <14 years was 0.14 cases per 100,000 children. Of the 17 cases with documentation on travel, 15 (88%) had recent travel outside of Alaska. In 2015, National Immunization Survey data estimated that among children aged 19-35 months, HAV vaccine coverage was similar in Alaska (84%) and all US children (86%).
The authors conclude: "Dramatic declines in the incidence of hepatitis A occurred after HAV vaccine was recommended as a routine childhood vaccine and after it was required for school entry. Prior to routine vaccination, most the reported HAV cases were associated with outbreaks occurring within Alaska. Since 2008 however, 88% of reported hepatitis A cases have been imported, many of which were acquired during travel outside of the United States."