The single most effective way to prevent hepatitis A is vaccination, which provides protection lasting at least 20 years after a complete two-dose series. Beyond vaccination, the virus spreads through contaminated food, water, and close personal contact, so a combination of good hygiene, safe food practices, and travel precautions rounds out your protection.
Vaccination Is the Strongest Protection
Hepatitis A vaccines are highly effective at preventing infection. The full series is two doses, and once you’ve completed both, the antibodies produced have been shown to persist for at least 20 years in follow-up studies. The exact upper limit of protection isn’t known yet, but immunity may well last a lifetime.
Children in the U.S. routinely receive the vaccine starting at age 1. If you weren’t vaccinated as a child, you can get the series as an adult at any age. The two doses are spaced at least six months apart, and both are needed for the strongest, longest-lasting protection.
Certain groups face a higher risk of infection or serious complications and should prioritize getting vaccinated if they haven’t already:
- International travelers, especially to regions with poor sanitation
- Men who have sex with men
- People who use or inject drugs
- People whose jobs increase exposure risk, such as lab workers handling the virus
- People experiencing homelessness
- Anyone with chronic liver disease, including hepatitis B or C, since hepatitis A can cause far more serious illness in this group
- People with HIV
If you’re unsure whether you were vaccinated in the past, a blood test can check for protective antibodies. The presence of a specific type of antibody (IgG anti-HAV) indicates you’re already immune, either from a prior infection or from vaccination.
Handwashing and Basic Hygiene
Hepatitis A is a hardy virus that spreads through the fecal-oral route, meaning tiny, invisible traces of contaminated stool reach your mouth through unwashed hands, food, or water. Thorough handwashing is your primary everyday defense.
Soap and water outperform alcohol-based hand sanitizers against non-enveloped viruses like hepatitis A. Research on similar viruses found that washing hands with soap and water for 30 seconds removed viral particles completely from finger pads, while alcohol-based sanitizers were significantly less effective. The key details: use any regular soap, scrub all surfaces of your hands for a full 30 seconds, and rinse under running water. This matters most after using the bathroom, after changing diapers, and before preparing or eating food.
Food Safety at Home and While Eating Out
Contaminated food is one of the most common vehicles for hepatitis A. Shellfish are a particular concern because they filter large volumes of water while feeding and can concentrate the virus in their tissues. Eating raw or undercooked shellfish harvested from polluted waters is a well-documented cause of outbreaks.
Cooking neutralizes the virus, but only at high enough temperatures. Heat inactivation requires reaching above 85°C (185°F) for at least one minute. That means steaming shellfish just until the shells open isn’t always sufficient. A rolling boil or thorough cooking to well above that threshold provides a wider margin of safety. Raw fruits and vegetables can also carry the virus if handled by an infected person or washed in contaminated water, so peeling produce yourself is a practical precaution when sanitation is uncertain.
Travel Precautions
International travel is one of the top risk factors for hepatitis A, particularly to parts of Central and South America, Africa, Asia, and Eastern Europe where the virus circulates widely. If you’re planning a trip to any of these regions, get your first vaccine dose as early as possible before departure. Even a single dose provides substantial short-term protection, though you’ll still need the second dose later to lock in long-term immunity.
While traveling, stick to bottled or boiled water for drinking and brushing your teeth. Bringing water to a full boil easily exceeds the 85°C threshold needed to kill the virus. Avoid ice in drinks unless you’re confident it was made from treated water. Choose hot, thoroughly cooked foods over raw salads, unpeeled fruits, or street food that may have been prepared with contaminated water or by someone carrying the virus.
What to Do After a Known Exposure
If you find out you’ve been exposed to someone with hepatitis A, acting quickly makes a real difference. Post-exposure treatment works best when given as soon as possible, and it must be started within two weeks of exposure to be effective.
For most people aged 12 months and older, the hepatitis A vaccine itself serves as the post-exposure treatment. Getting the first dose promptly after exposure can prevent the infection from taking hold. For people over 40, a provider may also add an injection of immune globulin (concentrated antibodies) depending on the situation, since vaccine-generated immunity may develop slightly more slowly with age. Infants under 12 months and people who can’t receive the vaccine for medical reasons get immune globulin instead.
People who are immunocompromised or have chronic liver disease face the highest stakes. If exposed, they typically receive both the vaccine and immune globulin simultaneously to maximize protection, since their immune systems may not respond to the vaccine quickly enough on its own.
Protecting Others if You’re Infected
Hepatitis A is most contagious in the two weeks before symptoms appear, which means you can spread it before you even know you’re sick. Once symptoms start (fatigue, nausea, abdominal pain, dark urine, jaundice), you remain contagious for roughly another week. During this window, meticulous handwashing after every bathroom visit, avoiding food preparation for others, and not sharing utensils or towels are the most important steps to protect the people around you.
The virus can survive on surfaces for weeks under the right conditions. Cleaning contaminated areas with a bleach-based disinfectant, rather than just soap, helps break the chain of transmission in households where someone is actively infected.