Hepatitis A Vaccination

Hepatitis A is a liver infection spread by the faecal-oral route, contaminated water, food washed in it, or food handled by an infected person. It does not become chronic: you either recover fully or, rarely, become seriously unwell. There is no long-term carrier state as there is with hepatitis B.

There is a paradox worth understanding for India specifically. Where sanitation is poor, most people are infected in early childhood, when the illness is usually mild or unnoticed, and emerge with lifelong immunity. As sanitation improves, that childhood exposure stops happening, so infections shift to adolescence and adulthood, when hepatitis A is a much more severe illness.

At a glance

Test before you vaccinate, if you grew up here

A hepatitis A IgG test tells you whether you already have immunity. For adults who grew up in India, particularly outside the largest cities and before the last two decades of sanitation improvement, the answer is frequently yes.

This is a case where a test genuinely saves money and injections. It is less relevant for children and young adults raised in cleaner water environments, who are increasingly susceptible into adulthood.

Who should be vaccinated

For those without existing immunity, several groups have a clear case.

• Anyone with chronic liver disease of any cause: hepatitis A on top of it is markedly more dangerous.
• Travellers to areas with uncertain food and water safety.
• Children, as part of an expanded schedule where families choose it.
• Food handlers, who can transmit widely if infected.
• People who eat frequently from street vendors or outside the home.
• Household contacts of someone infected, ideally within two weeks of exposure.
• Men who have sex with men, and people who inject drugs, both recognised risk groups.

Hepatitis A in adults is not a mild illness

In children under six, hepatitis A is frequently asymptomatic. In adults it typically means several weeks of jaundice, profound fatigue, nausea and loss of appetite, often with a month or more off work. Full recovery is the rule, but it is a long convalescence.

Acute liver failure is uncommon but real, and the risk rises with age and with existing liver disease. That combination, pre-existing liver disease plus acute hepatitis A, is the scenario the vaccine most clearly prevents.

After an exposure

If you have been exposed: a household member diagnosed, or a known food-source outbreak. The vaccine can still help if given promptly, generally within two weeks. For infants, older adults and the immunocompromised, immunoglobulin may be used alongside it. Come in quickly rather than waiting for symptoms.

Frequently asked questions