With unavailability of one of the pediatric preparations of Hepatitis B vaccine, is it permissible to administer two pediatric doses combined into one syringe for an adult?
Never combine vaccine from two syringes into one syringe, regardless of what the vaccine is. You can use the pediatric formulation of Hepatitis B vaccine, Recombivax-HB, to administer an adult dose of Hepatitis B vaccine, but you will have to administer it as two separate injections if the vaccine is in prefilled syringes. Engerix-B is not licensed for use in this way.
