What are the contraindications for hepatitis B vaccination?

Generally, contraindications for hepatitis B vaccination include allergy to vaccine components, being in the acute phase of an illness, having uncontrolled severe chronic diseases, pregnancy, and severely compromised immune function. The details are as follows:

1. Allergy to vaccine components: Individuals who previously experienced allergic reactions such as rash, difficulty breathing, or laryngeal edema after receiving the hepatitis B vaccine, or who are allergic to ingredients in the vaccine (such as yeast used in the production of some hepatitis B vaccines or preservatives), should not be vaccinated again to avoid the risk of severe allergic reactions.

2. Acute illness phase: Vaccination should be postponed if suffering from acute conditions such as influenza, acute gastroenteritis, or acute hepatitis, especially when accompanied by symptoms like fever (temperature above 38.5°C), fatigue, or vomiting. During this time, the body's immunity is weakened; vaccinating may worsen the existing condition and could impair the vaccine’s immunogenicity.

3. Uncontrolled severe chronic diseases: Patients with uncontrolled hypertension, diabetic complications, severe heart disease, chronic renal failure, or other serious chronic conditions have unstable physiological functions. Vaccination may increase physical stress and potentially trigger fluctuations in their condition. Vaccination should only be considered after the condition has stabilized, following medical evaluation.

4. Pregnant women: Currently, there is insufficient clinical data to confirm that the hepatitis B vaccine has no adverse effects on the fetus. For safety reasons, vaccination is generally not recommended during pregnancy. However, if a pregnant woman is at risk of exposure to hepatitis B virus (e.g., her partner is a hepatitis B patient), she should consult a physician to evaluate the risks and benefits before deciding whether to get vaccinated.

5. Severely impaired immune function: Individuals with severely compromised immune systems—such as those with HIV/AIDS, those taking long-term immunosuppressive drugs after organ transplantation, or those with severe immunodeficiency disorders—may not mount an effective immune response to the vaccine. As a result, vaccination may fail to produce protective antibodies and could even increase the risk of infection. Therefore, vaccination is generally not recommended for these individuals.

Before vaccination, individuals should honestly inform their healthcare provider about their health status and history of allergies, so the provider can assess suitability for vaccination. If any contraindications exist, vaccination should be delayed until the condition resolves, followed by timely catch-up dosing. After vaccination, individuals should remain under observation at the clinic for 30 minutes. If no adverse reaction occurs, they may leave; otherwise, seek medical attention promptly if any discomfort arises.