Hepatitis A Vaccine

What is Hepatitis A?

Hepatitis A is a liver disease caused by the Hepatitis A virus, which is commonly found in the feces of people with the disease. It can be spread through close personal contact, consuming contaminated food or water, or through other means of exposure to the virus. People with Hepatitis A can easily pass the virus on to others.

What causes Hepatitis A?

Hepatitis A is caused by the Hepatitis A virus (HAV), an RNA virus in the picornaviridae family.

Symptoms of Hepatitis A

In adults, symptoms typically start with fever, fatigue, loss of appetite, nausea, and abdominal discomfort, followed by jaundice within 2-3 days. Symptoms can range from mild to severe and can last anywhere from 1-2 weeks to several months in severe cases, although these are less common.

Most people recover completely without any lingering effects or a return of the illness. In children, the infection is often asymptomatic, with many infected individuals showing mild or no symptoms, and no jaundice. Diagnosis is typically made through liver function tests.

Destroying Hepatitis A virus

The following methods are used to properly dispose of feces, urine, and blood:

• Destroyed by heat at 85°C for 1 minute
• Formalin (8% for 1 minute at 25°C)
• Iodine (3 mg/liter for 5 minutes)
• Chlorine (free residual chlorine 2-2.5 mg/liter for 15 minutes)
• Seafood with shells such as clams, shrimp, and crabs that come from the sea which is contaminated with this virus should be cooked until it reaches at least 90°C for 4 minutes or use a pressure cooker for 90 minutes.

Who should receive the hepatitis A vaccine?

• Individuals aged 1 year or older who are planning to travel or work in countries with a high prevalence of hepatitis A virus such as Central America, South America, Asia (except Japan), Africa, and Eastern Europe.
• Individuals in professions at risk of exposure and transmission of the disease, such as food handlers, individuals who live in close proximity to large groups of people, including childcare facilities and military personnel.
• Medical personnel who come into contact with hepatitis A virus-infected patients or those who work in laboratories for research on hepatitis A virus.
• Tourists who are traveling to areas with high disease prevalence, such as Asia (excluding Japan), Central America, South America, the Caribbean, Africa, and Eastern Europe, should receive vaccinations.
  • It is recommended that family members of patients with hepatitis B receive vaccinations at least one month before traveling
  • Other groups that should receive vaccinations include men who have sex with men
  • Individuals who use drugs
  • People with chronic liver disease
  • Those who are being treated for blood clotting disorders.

When should the hepatitis A vaccine be administered?

• Children aged 2 years and above who have not previously received the vaccine.
• Individuals at risk may begin to receive the vaccine when they want to be protected against infection.
• For travelers, the vaccine course should be started at least 1 month before travel, with 2 doses administered at least 6 months apart.

How many doses and when should the hepatitis A vaccine be administered?

The vaccine should be given in 2 doses, the first dose and a booster dose 6-18 months later.

Precautions and warnings for receiving the hepatitis A vaccine:

• Individuals who have had a severe allergic reaction to the vaccine or any of its components should not receive the vaccine.
• Those who are ill should wait until they have recovered before receiving the vaccine.
• If pregnant, consult a physician before receiving the vaccine.
• Caution should be taken in individuals with low platelets or abnormal blood clotting.

Unintended effects of Hepatitis A vaccine

• Swelling, pain, and soreness at the injection site, headache, loss of appetite, and fatigue, which usually subside within 1-2 days.
• There may be a risk of severe allergic reactions, which typically occur within 2-3 minutes to 2-3 hours after vaccination, although this is very rare.

When should you see a doctor?

If there are any abnormal symptoms such as high fever or severe allergic reactions, including difficulty breathing, wheezing, hives, pale skin, or rapid heartbeat.

Best regards from the Vaccine Center of Vibhavadi Hospital.