INTRADERMAL HEPATITIS-B VACCINATION IN A 300-BED PRIMARY-CARE HOSPITAL - EXPERIENCE WITH A RECOMBINANT VACCINE IN A 4-DOSE SCHEDULE

Background: All hepatitis B vaccination programs, regardless of route: must address such factors as primary response rate, additional booster injections for primary nonresponders, antibody persistence, the need for and timing of additional booster injections for primary responders, overall costs, and medical efficacy. A voluntary intradermal hepatitis B vaccination program with postvaccination testing was implemented in a 300-bed primary care hospital with a recombinant vaccine packaged in a concentration of 20 mug/ml (Engerix B; SmithKline and French Laboratories, Philadelphia, Pa.). Methods: After informed consent was obtained, 460 employees were vaccinated intradermally over the deltoid muscle by a single employee health nurse at months 0 (initial), 1, 2. and 6, followed by testing for serologic response 1 to 2 months after the final dose. Results: Of 411 employees who completed the entire protocol, 90.5% had seroconversion, as determined by enzyme immunoassay. Twelve of 29 primary nonresponders (41%) had seroconversion after an additional (fifth) intradermal booster injection. Of the primary responders, 84.5% remained seropositive when tested 18 months after the initial vaccination injection. These results are comparable to those of intramuscular vaccination and to the original studies of intradermal vaccination with plasma-derived vaccines that had shown excellent immunogenicity. Conclusions: Intradermal and intramuscular hepatitis B vaccination programs must be implemented in somewhat different ways, but both can provide excellent protection against hepatitis B viral infection. Even allowing for the additional expense of postvaccination testing and mom frequent booster injections, intradermal vaccination greatly reduces the overall costs of hepatitis B vaccination and may therefore increase compliance in many different settings.