Study suggests Hepatitis A nearly eliminated among Alaska Native people-Continuing vaccination efforts credited with dramatic, sustained decline in casesSeptember 24, 2020
A new study published today indicates that successful ongoing vaccination efforts appear to have nearly eliminated hepatitis A virus infections among the Alaska Native population in Alaska. Hepatitis A is a short-term liver infection caused by the hepatitis A virus. Adults are more at risk than children of developing severe illness, which can cause liver failure and even lead to death. Before the introduction of an effective vaccine in the 1990s, the hepatitis A infection rate was high in the Alaska Native population, particularly among children. Following the introduction of routine childhood vaccination with inactivated hepatitis A vaccine in 1996, the reported incidence of hepatitis A declined by more than 99.9%.
The study, published in Clinical Infectious Diseases, examined infection rates between 1996 and 2018, using a combination of monitoring by the Alaska Native Tribal Health Consortium (ANTHC) and from the State of Alaska hepatitis surveillance system. The investigators found a dramatic decline in hepatitis A virus infections in the Alaska Native population with only 6 confirmed cases of infection between 1996 and 2018, and no confirmed cases between 2011 and 2018.
“Through hard work and collaboration among all Alaska Native tribal health organizations, ANTHC, the State of Alaska Department of Health and Human Services and CDC’s Arctic Investigations Program, the campaign to vaccinate all children and at-risk adults has resulted in the rate of acute hepatitis A infections in Alaska going from the highest in the United States to the lowest in the world in the past two decades,“ said Dr. Brian McMahon, Director of ANTHC’s hepatitis program.
The authors found several indications that the drop in cases reflected successful vaccination efforts. Vaccine was introduced early, with high coverage, and catch-up campaigns, and the findings of this study build on other evidence. The authors did not find any infections in people who were vaccinated, which fits with what is known about long-lasting protection from the vaccine. Of the 6 confirmed infections that were identified, only one was not linked to travel outside Alaska. None of the 6 infections occurred in patients who had been vaccinated.
Although hepatitis A appears to have been nearly eliminated in the Alaska Native population, continued protection with vaccination remains important. Reported increases in infections and outbreaks in other parts of the United States indicate that there remains a risk of hepatitis A infection, and especially if visiting other US states where outbreaks are occurring and countries where hepatitis A is still present.
The investigators found that the dramatic decline in hepatitis A in Alaska likely reflects many years of work ensuring that Alaska Native people as well as all Alaskan children had good access to vaccines, and acceptance of the vaccines within local communities. In the early 1990s, Alaska Native persons were among the first to receive the new hepatitis A vaccine in the United States and shortly after, hepatitis A vaccine became available for all children in Alaska. Uptake of vaccination has been high, above the national average. Public health catch-up campaigns, together with requirements for school children, have contributed to the high levels of vaccination among young Alaska Native and non-Native adults. Other studies from ANTHC and the CDC’s Arctic Investigations Program in Alaska have found that the protective effect of vaccine is likely to last into adulthood.
The study highlights the individual benefits of vaccine, as well as the benefits to the wider community.
“The findings show the powerful effect of vaccination and highlights how vaccine not only protects individuals, but also the whole population when enough people are vaccinated,” said Ian Plumb, CDC medical epidemiologist and the study’s lead investigator.
Currently, vaccination against hepatitis A is recommended for all children in the US up to 18 years of age, and for people at increased risk of infection or severe disease. The vaccine is available for any adult who requests it.
To learn more about other preventative programs and health services offered by ANTHC, please visit anthc.org/what-we-do/wellness