Revac-B Plus Pediatric Vaccine is an immunizing medicine used in the prevention of Hepatitis B infection. This medicine works by exposing the body to a small dose of the virus or its protein when injected, thus providing resistance to infection. Common side effects include headache, irritability, tiredness, drowsiness, nausea, diarrhoea, loss of appetite, fever, redness, tenderness and pain at the injection site.