# Hepatitis B Canonical page: https://carecard.ca/knowledge/immunizations-serology/hepatitis-b **Status:** Required for all students **Valid for:** Does not expire once an adequate anti-HBs titre confirms you are protected. This page explains why proof of hepatitis B immunity is required and how the vaccine works, using guidance from Health Canada and the Public Health Agency of Canada. It is educational and does not replace advice from your own health care provider or the specific rules of your program and placement site. See the [Source & references](#source--references) at the bottom. ## Why this is required [#why-this-is-required] Hepatitis B is a **bloodborne** infection, and as a medical student you may be exposed to blood and body fluids through needlestick injuries, splashes and patient care. This requirement is about confirming you are genuinely protected before that exposure can happen. * **Protects you.** Vaccination followed by a blood test proves you have built immunity against a virus you could be exposed to occupationally. * **Protects your patients.** An immune, non-infected health care worker cannot transmit hepatitis B to patients during care. * **It is usually already started.** Hepatitis B vaccine is part of routine immunization in Canada, so many students only need the confirmatory blood test or a top-up dose. Health Canada recommends that **all health care workers receive the hepatitis B vaccine and then have post-immunization blood testing** (an anti-HBs titre) **1 to 6 months after completing the series**, because of the risk of occupational exposure to blood and body fluids. This is why hepatitis B almost always involves a serology (blood test), not just a vaccination record. ## About hepatitis B [#about-hepatitis-b] Hepatitis B is caused by the hepatitis B virus (HBV), which spreads through contact with infectious body fluids — including sharing needles, sexual contact, and from mother to newborn at birth. It is a leading occupational risk in health care because it is transmitted through blood. * **Acute infection** is often silent: up to 50% of infected adults have no symptoms. * **Chronic infection** is the main danger — chronic carriers are at risk of cirrhosis and liver cancer (hepatocellular carcinoma). * **Risk of becoming a chronic carrier depends on age at infection:** about 90–95% for infants, 25–50% for young children, and 3–10% for adolescents and adults. ## How the vaccine works [#how-the-vaccine-works] The hepatitis B vaccine is a **recombinant (non-live) vaccine** — it contains a surface protein of the virus, made in the lab, that cannot cause infection. Your immune system responds by making antibodies (anti-HBs). It is given as a series (commonly three doses over about six months), sometimes in a combination vaccine. A blood test after the series then confirms your body has responded. ## How well it works [#how-well-it-works] * The vaccine is **95% to 100% effective** before exposure. * Anyone who develops an **anti-HBs titre of at least 10 IU/L** after completing the schedule is considered **protected for life** and does not need repeat testing or boosters (with some exceptions, such as people who are immunocompromised or on dialysis). ## Safety and side effects [#safety-and-side-effects] Reactions are usually **mild and transient**: * Pain and redness at the injection site * Irritability, headache or fatigue Serious adverse events are rare following hepatitis B immunization. ## Staying protected [#staying-protected] Once an adequate anti-HBs titre confirms you are protected, that protection is considered **lifelong** — no routine boosters are needed. If your titre is **below 10 IU/L**, Health Canada recommends a **second full vaccine series** followed by repeat testing; a second series produces protection in 50–70% of people who did not respond the first time. Leave enough time before placement, as the series and testing span several months. ## What to submit [#what-to-submit] * A record of your completed hepatitis B vaccine series, **and** * A lab report showing an **anti-HBs titre of 10 IU/L or higher** (proof of immunity) * Your full legal name and date of birth on every document ## Accepted proof [#accepted-proof] * Provincial or public health immunization record showing the HB series * Lab report of an anti-HBs (hepatitis B surface antibody) titre with the result clearly stated * Pharmacy or clinic immunization record * International immunization card with an English translation ## Good to know [#good-to-know] * A vaccination record alone is often **not enough** — most programs require the anti-HBs blood test proving your titre is 10 IU/L or higher. * If your titre is low, you may need a repeat series and retest, so start early. * Keep both documents together: the record of doses **and** the titre result. ## Validity [#validity] Does not expire once an adequate anti-HBs titre confirms you are protected. ## Source & references [#source--references] The medical information on this page is adapted from Health Canada and the Public Health Agency of Canada: * [Health Canada](https://www.canada.ca/en/health-canada.html) * [Hepatitis B vaccines: Canadian Immunization Guide](https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-7-hepatitis-b-vaccine.html) * [Immunization of workers: Canadian Immunization Guide](https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-3-vaccination-specific-populations/page-11-immunization-workers.html) * [Primary care management of hepatitis B — quick reference](https://www.canada.ca/en/public-health/services/reports-publications/primary-care-management-hepatitis-b-quick-reference.html)