Explanation:
The CDC recommends revaccination with recombinant hepatitis B vaccine with up to three additional doses for susceptible persons who do not develop protective antibody levels after an initial vaccination series. The intramuscular route is preferred, as there are no data regarding long-term protection following intradermal vaccination and the vaccine is not licensed for the intradermal route of administration. Freund’s adjuvant is not used with the hepatitis B vaccine.
