The hepatitis B vaccine is considered one of the safest vaccines ever made. It does not result in sudden infant deaths, multiple sclerosis or other neurological disorders. It takes only 3 shots to protect a child or adult against Hepatitis B throughout their life. The average cost of the three-shot Hepatitis vaccine is about $100 to $150. It costs more for adults. While insurance companies usually cover the cost of vaccine for infants and children, adults become eligible for insurance cover only if identified to be in high risk.