The Short Guide to Hepatitis A
Hepatitis A: the whole thing in five minutes, for when you want the numbers and nothing else.
A liver infection caused by the hepatitis A virus, spread when tiny amounts of stool from an infected person get into food, water or onto hands.
Key takeaways
- Childhood vaccine: 2 doses, starting at 12 to 23 months, given 6 months apart
- Adults who should be vaccinated: travelers to many countries, people at higher risk, and any adult who wants protection
- Most useful single change: Check whether you and your children have had both doses.
- Commonest mistake: Preparing food for others while you have symptoms.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
The numbers, in one place
| Measure | Figure |
|---|---|
| Childhood vaccine | 2 doses, starting at 12 to 23 months, given 6 months apart |
| Adults who should be vaccinated | travelers to many countries, people at higher risk, and any adult who wants protection |
| Time from exposure to symptoms | about 15 to 50 days |
| After an exposure | vaccine or immune globulin within 2 weeks can help prevent illness |
| Chronic infection | does not occur; most people recover fully |
In one paragraph
It can cause weeks of illness and, rarely, liver failure, and it is preventable with a safe, effective vaccine.
Worth doing
- Check whether you and your children have had both doses
- Ask about the vaccine at least a few weeks before international travel
- Wash hands with soap and water after using the toilet or changing diapers and before handling food
- Call your doctor or health department quickly after a known exposure
Worth avoiding
- Preparing food for others while you have symptoms
- Drinking alcohol or taking extra acetaminophen (Tylenol) while your liver is inflamed, unless your doctor agrees
- Drinking untreated water or eating raw shellfish where hepatitis A is common
Related topics
- Hepatitis B and C: What the Evidence Actually Says (Liver Health)
- The Evidence on Liver Health, Without the Hype (Digestive Health)
- Returning Traveler Illness: What Published Guidance Supports (Travel Health)
- The Evidence on Adult Vaccination, Without the Hype (Preventive Care)
Where to go next
- What Hepatitis A Is, and Why It Matters
- Hepatitis A: A Practical Checklist
- Hepatitis A — the reference entry
- Infectious Diseases: The Complete Guide
- The Evidence on Tuberculosis Basics, Without the Hype
- RSV (Respiratory Syncytial Virus): Sorting the Evidence From the Noise
When to speak to a doctor
See your doctor for yellowing of the skin or eyes, dark urine, pale stools, loss of appetite or pain on the right side of the belly. Call 911 for confusion, extreme sleepiness, vomiting blood or easy bleeding or bruising, which can signal liver failure.
Where this comes from
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.
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