Hepatitis A is a viral disease that affects liver cells causing acute symptoms such as jaundice, fever, and hepatomegaly. Luckily, there’s a vaccine against hepatitis A, and it is beneficial to prevent this ailment.
According to studies, the efficacy of this hepatitis A vaccine ranges between 80 – 100% of immunization after 2 doses. It is typically administered to individuals who are traveling to endemic areas. In other words, the regions where hepatitis A is ubiquitous. In these cases, immunization should be completed 2 weeks before departure. If the individual travels to endemic areas very frequently, he can combine the vaccine with intramuscular immunoglobulins to protect against the virus.
This vaccine is not recommended in patients who already have severe liver conditions because they do not develop significant immunity. But people with mild to moderate chronic liver conditions may receive the vaccine. It is also implemented in food handlers and other employers that may become a potential outbreak source.
Mechanism of action and administration
The hepatitis A virus vaccine has an attenuated strain of this virus. It is not a dead virus, but it is not capable of causing the infection, either. What it does is stimulating the organism to create active immunity against hepatitis A. The antigen-presenting cells detect the foreign microorganisms, take a sample to lymphocytes that develop antibodies and start growing defenses against the virus.
The onset of these actions takes around 4 weeks, and the immunization duration is currently unknown. However, we do know that the duration is long-lasting. After several years, most patients are still immune to hepatitis A when given an appropriate first dose and booster schedule.
The administration of this vaccine comes in prefilled syringes with doses for children or adults. They should be kept refrigerated at 36 to 45 ºF and should not be diluted. Hepatitis A virus vaccines should be shaken to obtain a whitish suspension and should only be administered. The suspension should be slightly opaque and completely homogeneous without discolorations or particulate matter. It is administered in intramuscular injections in the deltoid region of children aged 2 years or older, adolescents, and adults. In younger children, it should be administered in the anterolateral part of the thigh.
