• Hepatitis A is caused by a picorna-virus with six genotypes but only one serotype.
  • Hepatitis A-virus is spread via person-to person-contact, by water or by food.
  • Thus, countries with poor hygiene and sanitation have highest incidences of infection and young children play a major role as source of the infection. 
  • Infection with HAV produces life-long immunity to re-infection.
  • Exposure to hepatitis A-virus may result in asymptomatic infection (frequent in children), in «classical» icteric disease, or in fulminant disease, which may result in death. While there is a plethora of complications, overall, these are infrequent.
  • There is no specific treatment.
  • Passive immunization with human immunoglobulin before or early after exposure reduces the frequency for symptomatic infection.
  • There are several inactivated vaccines available world-wide.
  • Even following a single dose only, immunogenicity of these vaccines is high; however, a second dose is routinely given and may provide improved long-term immunogenicity.
  • Protection rates in clinical trials were 94-100%.
  • While the duration of protection following vaccination is not yet known, observations and mathematical modelling of antibody persistence suggest that protection may persist at least 25 years. 
  • After a dose of a hepatitis A vaccine, local and systemic reactions occur frequently, but they are mild and acceptable. 
  • Routine use of hepatitis A vaccine has been highly efficacious in decreasing incidences of the disease.