The hepatitis B virus can spread through blood, semen, and vaginal fluids. Therefore, unprotected sexual contact with an infected person is considered an exposure. However, exposure does not guarantee infection; the risk depends on the wife's infection status and the husband's immune response.

Individuals should seek medical attention as soon as possible, ideally within 24 hours. Bring any vaccination records if available. Post-exposure prophylaxis is most effective when administered promptly. For sexual exposure, benefits are typically seen within 14 days. Even beyond this timeframe, exposed individuals still need medical evaluation for testing, vaccination counseling, and appropriate monitoring. Do not wait for symptoms to appear, as acute hepatitis B can progress silently.

Couples should openly discuss any infectious diseases they may have to enable prevention. *Vecteezy*

A doctor may order a panel of three tests: HBsAg, anti-HBs, and total anti-HBc. These results determine if the person being tested is currently infected, was previously infected, has immunity, or remains at risk. Relying solely on an anti-HBs level in someone vaccinated as a child might not provide a complete picture, as antibody levels can decrease over time while immune memory persists.

The next steps depend on test results and previous vaccination records:

If records show complete vaccination and a protective antibody response, no further vaccination is needed after this exposure.

If vaccination was complete but post-vaccination response was never checked, the doctor might consider an additional vaccine dose if the exposure source is HBsAg positive.

If vaccination is incomplete, there is no proof of vaccination, or tests indicate susceptibility, the doctor may prescribe hepatitis B immunoglobulin (HBIG) and initiate or complete the vaccination schedule as soon as possible.

Do not self-purchase vaccines or request immunoglobulin injections solely based on "not remembering if vaccination was complete." HBIG and vaccines have different indications and must be prescribed by a doctor based on records, test results, exposure time, and immune status.

While awaiting evaluation, the couple should use condoms until the husband's immunity is confirmed or preventive measures are completed as advised. Avoid sharing toothbrushes, razors, nail clippers, or any objects that might have blood on them. Cover open wounds and thoroughly clean any blood-stained surfaces.

Hepatitis B is not transmitted through hugging, shaking hands, coughing, sneezing, or sharing food and drinks. Therefore, the couple does not need to use separate utensils or limit normal social interactions. The wife should continue follow-up care with a hepatologist to monitor liver enzymes, viral load, and determine treatment if necessary.

Healthy individuals who have completed the hepatitis B vaccine series and have a normal immune system generally do not require annual antibody testing or booster shots. However, those living with or having sexual contact with a person with hepatitis B are a group that needs specific immune status checks and personalized counseling. Following prophylaxis, the doctor will schedule appropriate retesting, which may change if HBIG was administered.

Doctor Phan Nguyen Truong Giang

Medical Manager, VNVC Vaccination System

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