Elovac-B 20mcg Injection is an active immunizing agent. It is used for the prevention of hepatitis B infection in individuals considered at risk of exposure to hepatitis B virus. Elovac-B 20mcg Injection is administered by a healthcare professional and should not be self-administered. For the vaccine to be effective, you have to receive all the doses. It is generally safe and well-tolerated. However, it may cause fatigue and injection site reactions such as redness, swelling, or pain in some people. If you are bothered by such reactions, let the doctor know. The doctor may help with ways to reduce or prevent these symptoms. To make sure the vaccine is safe, before receiving the vaccine, it is important to let the doctor know if you have any other illnesses. You should also tell the doctor about all the medicines you are taking. Pregnant and breastfeeding mothers should consult and seek advice from their doctor before receiving the vaccine.