Hepatitis A vaccine symptoms: what to expect

A tender or warm injection site reflects a local immune response. Feeling generally unwell, mild fever, headache, or muscle aches can occur as the body responds to the vaccine. These reactions do not mean the vaccine has caused hepatitis A; the vaccine cannot give you the infection. Nausea or reduced appetite can also occur, but persistent symptoms may have another cause, including hepatitis A itself. Hepatitis A can affect the liver and may cause dark urine, nausea, or loss of appetite.

Rest, drink fluids, and keep the arm moving gently if it is comfortable. A cool, clean compress may ease local soreness. Follow the product advice or a clinician’s advice before taking medicine for fever or pain, especially if you have liver disease, take regular medicines, or are caring for a child. Record when symptoms began and whether they are improving. If symptoms continue, a clinician can assess you and may consider a Liver Function Test.

Seek urgent help for trouble breathing, swelling of the face or throat, widespread hives, fainting, or sudden severe weakness after vaccination. Contact a clinician promptly for a high or persistent fever, worsening illness, repeated vomiting, yellowing of the skin or eyes, or dark urine. These symptoms need assessment because they may indicate an allergic reaction, another illness, or liver inflammation rather than a routine injection-site response.

Ask which symptoms are expected for the vaccine you received, whether your medical history changes the advice, and what pain or fever medicine is suitable. You can also ask whether you need an appointment if symptoms overlap with Hepatitis A.