Persistence of antibody to hepatitis B surface antigen after low-dose, intradermal hepatitis B immunization and response to a booster dose

Intralesional Versus Intramuscular Hepatitis B Virus Vaccine in the Treatment of Multiple Common Warts

BACKGROUND

Hepatitis B virus (HBV) vaccination is associated with stimulation of humoral and cell-mediated immunity. Intralesional HBV vaccine has been recently used as an immunotherapy of common warts with relatively low success rate.

AIM

To assess the efficacy and safety of intralesional versus intramuscular (IM) HBV vaccine in the treatment of multiple common warts.

PATIENTS AND METHODS

The study included 60 patients with multiple common warts who were randomly assigned to 2 groups: intralesional HBV vaccine or IM HBV vaccine. In the intralesional HBV vaccine group, the vaccine was injected into the largest wart at 2-week intervals until complete clearance or for a maximum of 5 sessions. Intramuscular HBV vaccine group received 3 injections in the deltoid muscle at 0, 1, and 6 months.

RESULTS

Complete wart clearance was reported in 7 patients (23.3%) of the intralesional HBV vaccine group and 15 patients (50%) of the IM HBV vaccine group. The difference was statistically significant in favor of the IM group ( p = .0479). Adverse effects were mild and insignificant in the 2 groups.

CONCLUSION

HBV vaccine, particularly the IM form seems to be a promising, well-tolerated therapeutic option for the treatment of warts.

LIMITATIONS

Short follow-up period and small sample size.

In-vivo Intradermal Delivery of Co-57 labeled Vitamin B-12, and Subsequent Comparison with Standard Subcutaneous Administration

Vitamin B-12 (cobalamin) deficiency in humans is a worldwide problem emanating from varied causes such as insufficient dietary intake or malabsorption of the micronutrient due to an underlying condition (absence or failure of intrinsic factor, atrophic gastritis, post-operative bariatric surgery, inflammatory bowel disease, cobalt deficiency etc.). As oral supplementation is limited by its bioavailability due to the absorptive property of intrinsic factor, clinicians often prescribe parenteral forms of administration to replenish diminished levels rapidly. The gold standard in parenteral delivery of cobalamin is subcutaneous and/or intramuscular injections. The relatively large molecular size of cobalamin (1355.39 Da) makes passive transdermal patch-based delivery via the stratum corneum quite challenging. Hence, the primary goal of this study is to investigate the feasibility of intradermal (ID) delivery of Vitamin B-12 via an almost painless microneedle injection and subsequent comparison with standard subcutaneous (SC) delivery. This work reports on a custom-made microneedle device built from a commercial insulin needle and it's use to perform ID delivery of Co-57 radiolabeled Vitamin B-12 in-vivo in rabbits. The pharmacokinetic profile and bioavailability were studied and compared with SC delivery. It is the first comprehensive study, to our best knowledge, that compares a micronutrient (eg. Vitamin B-12) delivery via ID and SC routes in-vivo. While the bioavailability for the SC route is found to be slightly higher compared to the ID route (99% vs. 96%), the T_max for both are almost identical. Thus, ID delivery of Vitamin B-12 using a microneedle injection could be a viable and minimally invasive alternative to existing parenteral options.

Intradermal vaccination for infants and children

Intradermal (ID) vaccination induces a more potent immune response and requires lower vaccine doses as compared with standard vaccination routes. To deliver ID vaccines effectively and consistently, an ID delivery device has been developed and is commercially available for adults. The clinical application of ID vaccines for infants and children is much anticipated because children receive several vaccines, on multiple occasions, during infancy and childhood. However, experience with ID vaccines is limited and present evidence is sparse and inconsistent. ID delivery devices are not currently available for infants and children, but recent studies have examined skin thickness in this population and reported that it did not differ in proportion to body size in infants, children, and adults. These results are helpful in developing new ID devices and for preparing new vaccines in infants and children.

Delivering vaccines into the skin without needles and syringes

The skin is a highly accessible organ and due to the presence of powerful antigen-presenting cells in the epidermis, it functions as an immune barrier. This makes the skin an attractive route for potential delivery of vaccines by painless and user-friendly methods without the requirement of needles and syringes. This article reviews current attempts to administer vaccines into the skin and discusses some of the scientific issues related to the emerging delivery technologies.

Protective immunity in mice achieved with dry powder formulation and alternative delivery of plague F1-V vaccine

The potential use of Yersinia pestis as a bioterror agent is a great concern. Development of a stable powder vaccine against Y. pestis and administration of the vaccine by minimally invasive methods could provide an alternative to the traditional liquid formulation and intramuscular injection. We evaluated a spray-freeze-dried powder vaccine containing a recombinant F1-V fusion protein of Y. pestis for vaccination against plaque in a mouse model. Mice were immunized with reconstituted spray-freeze-dried F1-V powder via intramuscular injection, microneedle-based intradermal delivery, or noninvasive intranasal administration. By intramuscular injection, the reconstituted powder induced serum antibody responses and provided protection against lethal subcutaneous challenge with 1,000 50% lethal doses of Y. pestis at levels equivalent to those elicited by unprocessed liquid formulations (70 to 90% protection). The feasibility of intradermal and intranasal delivery of reconstituted powder F1-V vaccine was also demonstrated. Overall, microneedle-based intradermal delivery was shown to be similar in efficacy to intramuscular injection, while intranasal administration required an extra dose of vaccine to achieve similar protection. In addition, the results suggest that seroconversion against F1 may be a better predictor of protection against Y. pestis challenge than seroconversion against either F1-V or V. In summary, we demonstrate the preclinical feasibility of using a reconstituted powder F1-V formulation and microneedle-based intradermal delivery to provide protective immunity against plague in a mouse model. Intranasal delivery, while feasible, was less effective than injection in this study. The potential use of these alternative delivery methods and a powder vaccine formulation may result in substantial health and economic benefits.

Preclinical evaluation of microneedle technology for intradermal delivery of influenza vaccines

Recent clinical studies have suggested that, for certain strains of influenza virus, intradermal (i.d.) delivery may enable protective immune responses using a lower dose of vaccine than required by intramuscular (i.m.) injection. Here, we describe the first preclinical use of microneedle technology for i.d. administration of three different types of influenza vaccines: (i) a whole inactivated influenza virus, (ii) a trivalent split-virion human vaccine, and (iii) a plasmid DNA encoding the influenza virus hemagglutinin. In a rat model, i.d. delivery of the whole inactivated virus provided up to 100-fold dose sparing compared to i.m. injection. In addition, i.d. delivery of the trivalent human vaccine enabled at least 10-fold dose sparing for the H1N1 strain and elicited levels of response across the dose range similar to those of i.m. injection for the H3N2 and B strains. Furthermore, at least fivefold dose sparing from i.d. delivery was evident in animals treated with multiple doses of DNA plasmid vaccine, although such effects were not apparent after the first immunization. Altogether, the results demonstrate that microneedle-based i.d. delivery elicits antibody responses that are at least as strong as via i.m. injection and that, in many cases, dose sparing can be achieved by this new immunization method.

Intradermal vaccination of adults with three low doses (2 µg) of recombinant hepatitis B vaccine. II. Persistence of immunity and induction of immunologic memory

Of the 110 dentists who had presented seroconversion 50 days after the intradermal application of three 2 micrograms doses of the Belgian recombinant vaccine against hepatitis B (HB), administered eight years before at an interval of one month between the 1st and 2nd doses and of five months between the 2nd and 3rd doses, 51 were included for the assessment of the persistence of immunity. None of the dentists had hepatitis or had received HB vaccine during this period. All subjects were submitted to serological tests for the detection of the following markers of hepatitis B virus (HBV) infection: HBsAg, anti-HBc, HBeAg, anti-HBe, and anti-HBs, with no HBsAg, anti-HBc, HBeAg or anti-HBe being detected. A microparticle enzyme immunoassay (MEIA) revealed the presence of anti-HBs at protective titers (> or = 10 mIU/ml) in 42 dentists (82.4%), with the anti-HBs titer being higher than 100 mIU/ml in 36 of them (70.6%) (good responders), between 10 and 100 mIU/ml in 6 (11.8%) (poor responders), and lower than 10 mIU/ml in 9 (17.6%) (non-responders). According to clinical data and serological tests, none of the dentists had presented disease or latent HBV infection during the eight years following the first vaccination. A 2 micrograms booster dose was administered intradermally to eight dentists with anti-HBs titers lower than 10 mIU/ml (non-responders) and to six dentists with titers ranging from 10 to 100 mIU/ml (poor responders); the determination of anti-HBs one month later demonstrated the occurrence of seroconversion in the eight non-responders and an increase in anti-HBs titer in the six poor responders. In summary, the present results demonstrated the prolonged persistence of protection against HBV infection and the development of immunologic memory provided by vaccination against HB--with intradermal application of three 2 micrograms doses of the Belgian recombinant vaccine at 0, 1, and 6 months--carried out eight years before in 51 dentists.

Hepatitis B vaccine booster dose: low-dose recombinant hepatitis B vaccines as a booster dose

BACKGROUND

The timing and best regimen for a booster dose of hepatitis B vaccine have not been determined.

METHODS

Two studies were conducted to determine the response to a booster dose of 5 micrograms recombinant hepatitis B vaccine. In the first study, a 5 micrograms (0.5 ml) dose of Recombivax HB was administered intramuscularly 38 months after the initial dose to 71 volunteers. In a second study, we offered a 5 micrograms dose recombinant hepatitis B vaccine, either Recombivax HB (0.5 ml) or Engerix B (0.25 ml), to students who had previously been immunized with three doses of vaccine.

RESULTS

In the first study, among the 44 persons for whom postbooster sera were available, the geometric mean concentration of anti-hepatitis B surface antigens increased from 42 to 2090 mIU/ml after the 5 micrograms (0.5 ml) dose of Recombivax. In the second study, after a 5 micrograms (0.5 ml) dose of Recombivax, the geometric mean concentration increased from 43 to 990 mIU/ml (n = 48), and in the group that received a 5 micrograms (0.25 ml) dose of Engerix B, the concentration increased from 83 to 2337 mIU/ml (n = 45) (p = 0.18 for postdose concentrations).

CONCLUSION

A 5 micrograms dose of recombinant vaccine results in an excellent booster response at a cost one fourth to one half that of a full 1 ml dose of vaccine.

Intradermal hepatitis B vaccination in a 300-bed primary care hospital: experience with a recombinant vaccine in a four-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 micrograms/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 more frequent booster injections, intradermal vaccination greatly reduces the overall costs of hepatitis B vaccination and may therefore increase compliance in many different settings.