Hepatitis A is an infectious, highly contagious liver disease caused by a virus called hepatitis A. The Centers for Disease Control and Prevention (CDC) recommends that all children receive the hepatitis A vaccine between 12 and 23 months of age to prevent the future development of this infection. The hepatitis A vaccine is administered as two separate injections given at least six months apart. Before you or your child are vaccinated, discuss the hepatitis A vaccine risks with your doctor.
Injection Site Reaction
The hepatitis A vaccine is administered as an injection within the muscle (intramuscular injection) of your upper arm. After receiving this vaccine, you can experience an injection site reaction as a side effect. Approximately 50 percent of adults and 20 percent of children develop soreness near the injection site, explain CDC health officials. Additional injection site reactions can include redness, swelling or bruising, which can contribute to sensations or tenderness or soreness. These side effects typically resolve one to two days after receiving the hepatitis A vaccine. Contact your doctor if you develop a skin rash or persistent itching or swelling at the injection site, as these symptoms can be indicative of a severe reaction to this vaccine.
Fatigue
Use of the hepatitis A vaccine can increase your risk of experiencing fatigue, explains Medline Plus, a medical website established by the U.S. National Library of Medicine and the National Institutes of Health. Excessive drowsiness or fatigue can arise within hours following the administration of this vaccine and can persist for several days. Daytime fatigue may affect your productivity at work or school and can cause young children to become fussy or irritable.
Headache
An estimated 20 percent of adult hepatitis A vaccine recipients are at risk of developing a headache following vaccination, reports the CDC. Headache symptoms are typically mild but can persist for several days. Headache pain may also occur in conjunction with neck or body aches in certain patients. Use of an over-the-counter analgesic medication, such as acetaminophen, may help alleviate headache symptoms.
Flu-like Symptoms
You are at an increased risk of developing flu-like symptoms after receiving the hepatitis A vaccine. These symptoms can include muscle aches, decreased appetite, sore throat, nasal congestion, cough or weakness, warn doctors at the Mayo Clinic. Certain patients can also develop a low-grade fever (typically 100 degrees Fahrenheit or higher) following hepatitis A vaccination, which can exacerbate headache and fatigue side effects.
