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Infectious Disease9 papers

Encephalitis caused by hepatitis A vaccine

Last edited: 4/10/2026

Overview

Encephalitis is an inflammation of the brain, most commonly caused by infections. Hepatitis A virus (HAV) is a common cause of viral hepatitis, and while typically self-limiting, can lead to complications.

Diagnosis

Management

Special Populations

  • Universal hepatitis A vaccination without screening was found to be cost-effective among children in middle-income countries (9/11 studies) and high-income countries (4/6 studies) 2.
  • Universal hepatitis A vaccination without screening was cost-effective in 87.5% of studies among children and 20% of studies among adolescents 2.
  • Universal hepatitis A vaccination without screening was not found to be cost-effective in adults in the reviewed studies 2.
  • Key Recommendations

  • Hepatitis A vaccination is immunogenic and safe in adults aged 18 years and above 1.
  • A two-dose hepatitis A vaccine regimen administered with a 6-month interval achieved 100% seropositivity and seroconversion rates in adults 1.
  • No serious adverse events related to hepatitis A vaccination were reported in a study of adults 1.
  • Universal hepatitis A vaccination without screening is cost-effective in children 2.
  • References

    1 Chang L, Li Z, Liu Y, Fei S, Zhao L, Li J et al.. Immunogenicity and safety of hepatitis A vaccine at different vaccination intervals among adults aged 18 years and above: Interim results. Human vaccines & immunotherapeutics 2025. link 2 Gurav YK, Bagepally BS, Thakkinstian A, Chaikledkaew U, Thavorncharoensap M. Economic evaluation of hepatitis A vaccines by income level of the country: A systematic review. The Indian journal of medical research 2022. link

    Original source

    1. [1]
      Immunogenicity and safety of hepatitis A vaccine at different vaccination intervals among adults aged 18 years and above: Interim results.Chang L, Li Z, Liu Y, Fei S, Zhao L, Li J et al. Human vaccines & immunotherapeutics (2025)
    2. [2]
      Economic evaluation of hepatitis A vaccines by income level of the country: A systematic review.Gurav YK, Bagepally BS, Thakkinstian A, Chaikledkaew U, Thavorncharoensap M The Indian journal of medical research (2022)
    3. [3]
    4. [4]
      Hepatitis a virus vaccine escape variants and potential new serotype emergence.Pérez-Sautu U, Costafreda MI, Caylà J, Tortajada C, Lite J, Bosch A et al. Emerging infectious diseases (2011)
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      Virosomal hepatitis a vaccine: comparing intradermal and subcutaneous with intramuscular administration.Frösner G, Steffen R, Herzog C Journal of travel medicine (2009)
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      Use of hepatitis A vaccine in a community-wide outbreak of hepatitis A.Craig AS, Sockwell DC, Schaffner W, Moore WL, Skinner JT, Williams IT et al. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (1998)
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      Prevention of hepatitis A and B.Bell S, Watson K Australian family physician (1997)
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      Prevention of hepatitis A through active or passive immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. Recommendations and reports : Morbidity and mortality weekly report. Recommendations and reports (1996)
    9. [9]
      New developments in hepatitis A control.Yuan L Canadian family physician Medecin de famille canadien (1995)
    10. [10]
      Public health control of hepatitis A: memorandum from a WHO meeting. Bulletin of the World Health Organization (1995)
    11. [11]
    12. [12]
    13. [13]
      Reactogenicity and immunogenicity of three different lots of a hepatitis A vaccine.Theilmann L, Kallinowski B, Gmelin K, Hofmann F, Scheiermann N, Wohland B et al. Vaccine (1992)
    14. [14]
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      An inactivated hepatitis A viral vaccine of cell culture origin.Provost PJ, Hughes JV, Miller WJ, Giesa PA, Banker FS, Emini EA Journal of medical virology (1986)

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