Comparison of the immunogenicity of hepatitis B vaccine administered intradermally and intramuscularly

Vaccine uptake and immune responses to HBV infection amongst vaccinated and non-vaccinated healthcare workers, household and sexual contacts to chronically infected HBV individuals in the South West Region of Cameroon

Background

HBV infection affects about 257 million people globally and Sub-Saharan Africa has the highest burden. The disease still constitutes a major public health problem despite the advent of preventive measures like the HBV vaccine. This study was aimed at identifying factors that influence vaccine uptake and the efficacy of administered vaccines among people at high risk of HBV infection.

Methods

This was a cross-sectional study conducted between January 2016 and December 2017. A pretested semi-structured questionnaire was used to capture information on sociodemographic and vaccination status from healthcare workers, household and sexual contacts to HBV infected people. HBV serological panel as well as quantitative anti-HBs ELISA test was done for all participants. Additional information was obtained from the institutions that administered the vaccines.

Results

A total of 265 participants with a mean age of 32.1±8.7 were enrolled. Eighty (30.2%) of them had received at least 1 dose of the HBV vaccine while 185 (69.8%) were unvaccinated. Healthcare workers were the most vaccinated (37%). Ignorance, negligence, fear of injection and the cost of the vaccine all contributed to poor vaccine uptake in the study population. Natural immunity was seen in 9 (3.4%) of the participants. Only 64.9% of the vaccinated participants attained the desirable level of anti-HBs (≥10mIU/ml) 1–2 months after ≥ 3 doses of the vaccine. Age, gender, obesity, alcohol and smoking were not significantly associated with poor immune responses. No standardized protocol was followed by the institutions administering the vaccine.

Conclusion

This study revealed very poor vaccine uptake and poor immune responses to the HBV vaccine in the study population and this should urge the health sector in Cameroon to intensify their sensitization on HBV vaccine, standardize the protocol for storing and administering the vaccine, subsidize the cost of the vaccine especially amongst healthcare workers and encourage anti-HBs post vaccination testing.

Cancer Vaccines in Ovarian Cancer: How Can We Improve?

Epithelial ovarian cancer (EOC) is one important cause of gynecologic cancer-related death. Currently, the mainstay of ovarian cancer treatment consists of cytoreductive surgery and platinum-based chemotherapy (introduced 30 years ago) but, as the disease is usually diagnosed at an advanced stage, its prognosis remains very poor. Clearly, there is a critical need for new treatment options, and immunotherapy is one attractive alternative. Prophylactic vaccines for prevention of infectious diseases have led to major achievements, yet therapeutic cancer vaccines have shown consistently low efficacy in the past. However, as they are associated with minimal side effects or invasive procedures, efforts directed to improve their efficacy are being deployed, with Dendritic Cell (DC) vaccination strategies standing as one of the more promising options. On the other hand, recent advances in our understanding of immunological mechanisms have led to the development of successful strategies for the treatment of different cancers, such as immune checkpoint blockade strategies. Combining these strategies with DC vaccination approaches and introducing novel combinatorial designs must also be considered and evaluated. In this review, we will analyze past vaccination methods used in ovarian cancer, and we will provide different suggestions aiming to improve their efficacy in future trials.

Whole Tumor Antigen Vaccines: Where Are We?

With its vast amount of uncharacterized and characterized T cell epitopes available for activating CD4⁺ T helper and CD8⁺ cytotoxic lymphocytes simultaneously, whole tumor antigen represents an attractive alternative source of antigens as compared to tumor-derived peptides and full-length recombinant tumor proteins for dendritic cell (DC)-based immunotherapy. Unlike defined tumor-derived peptides and proteins, whole tumor lysate therapy is applicable to all patients regardless of their HLA type. DCs are essentially the master regulators of immune response, and are the most potent antigen-presenting cell population for priming and activating naïve T cells to target tumors. Because of these unique properties, numerous DC-based immunotherapies have been initiated in the clinics. In this review, we describe the different types of whole tumor antigens that we could use to pulse DCs ex vivo and in vivo. We also discuss the different routes of delivering whole tumor antigens to DCs in vivo and activating them with toll-like receptor agonists.

Intradermal, epidermal and transcutaneous vaccination: from immunology to clinical practice

The dermis and epidermis are alternative sites for prophylactic vaccination that have received renewed interest in recent years, not only because of the ease of access to the skin, but also its unique immunological properties. This review discusses the characteristics of the skin, current knowledge on skin immunity and clinical experience with cutaneous immunization against infectious diseases, with a special focus on intradermal immunization. The most widely accepted paradigm explaining the efficacy of cutaneous immunization is reviewed and recent research suggesting where this paradigm may need some refinement is highlighted. Clinical investigations that have concentrated on the intradermal route to vaccinate against influenza, rabies or hepatitis B support the current knowledge on skin immunity and, when combined with recent progress made in the development of user-friendly injection systems, have stimulated the ongoing clinical development of novel vaccines.

Low-dose intradermal administration of recombinant hepatitis B vaccine in children: 5-year follow-up study

Several studies have documented the efficacy of low-dose intradermal administration of hepatitis B vaccine. However, little is known about the duration of protection provided by low-dose intradermal administration of hepatitis B vaccine. This study reports results from a 5-year follow up period of 200 healthy children (100 infants and 100 preschool children) immunized intradermally with 2 microg doses of recombinant hepatitis B vaccine (GenHevac B) at months 0,1, and 6. In the 8th week after the third vaccine dose, 97% of the children developed anti-HBs antibodies higher than or equal to 10 mlU ml(-1), and the antiHBs geometric mean titre (GMT) was 676 mlU ml(-1). In month 18 and year 5, the anti-HBs GMT decreased to approximately one-third (220 mlU ml(-1)) and one-tenth (68 mlU ml(-1)) of the initial levels, respectively. However, 87% of the children had protective levels of anti-HBs (> or =10 mlU ml(-1)) after 5 years. Among 156 children followed for 5 years, none became positive for anti-HBc and/or HbsAg. Seven children who were seronegative after 5 years developed anti-HBs antibodies higher than 1000 mlU ml(-1) after an additional 10 microg intramuscular hepatitis B vaccine. Persistent immunologic memory over periods of 5 years or more is evident, the anamnestic antibody response to a booster dose of vaccine, even in these children who have lost antibody. We conclude that intradermal administration of 2 microg recombinant hepatitis B vaccine provides long-term protection against hepatitis B virus in infants and preschool children.

Randomised trial of intradermal Mycobacterium vaccae or intradermal hepatitis B immunisation in children with HIV infection

This study assessed the safety of inactivated Mycobacterium vaccae as a candidate vaccine to prevent disseminated mycobacterial disease in children with HIV infection. 35 children ages 1-8 with CD4 counts > or =300/mm3 in New Hampshire, Boston and Chicago were randomised in a 2:1 schedule to receive a 3-dose series of intradermal M. vaccae vaccine (MV) or hepatitis B vaccine (HBV) at 2-month intervals. Immunisation was safe and well tolerated; 2-day median vaccine site in duration was 5 mm in MV recipients and 0 mm in HBV recipients (p < 0.001). There were no significantly different changes in viral load or CD4 count between the two vaccine groups. No PPD skin test conversions occurred after immunisation. MV is safe and well tolerated and deserves further evaluation as a vaccine to prevent mycobacterial disease in HIV-infected children.

Low-dose intradermal versus intramuscular administration of recombinant hepatitis B vaccine: a comparison of immunogenicity in infants and preschool children

Two hundred infants and two hundred preschool children were randomly assigned to receive either 10 micrograms of recombinant hepatitis B vaccine (GenHevac B) intramuscularly (i.m.) or 2 micrograms intradermally (ID) in the deltoid region at 0, 1 and 6 months. Antibody to hepatitis B surface antigen (anti-HBs) was tested eight weeks after the third vaccine dose. Standard dose i.m. and low-dose ID administration of recombinant hepatitis B vaccine produced comparable rates of anti-HBs equal to or higher than 10 mIU ml-1 in infants (98% and 94%, respectively) and preschool children (98% and 100%, respectively). Although i.m. vaccination produced higher anti-HBs concentrations than ID vaccination both in infants (geometric mean titre-GMT, 935 versus 621 mIU ml-1) and preschool children (GMT, 1393 versus 804 mIU ml-1), the differences were not statistically significant (p > 0.05). The preschool children tended to have higher anti-HBs concentrations than the infants. No clinically serious adverse effects were observed in both vaccine groups; however, induration and hyperpigmentation at the injection site were more often seen in the study population that was vaccinated intradermally. We conclude that intradermal administration of 2 micrograms recombinant hepatitis B vaccine is safe and effective in infants and preschool children, and may be an acceptable, less expensive alternative to full-dose i.m. vaccination for mass immunization, especially in developing countries.

Immunogenicity of low-dose intramuscular and intradermal vaccination with recombinant hepatitis B vaccine

The study is a randomized trial using recombinant DNA vaccine to determine whether an intramuscular 10 micrograms dose or intradermal 2 micrograms induces satisfactory anti-HBs levels compared to the standard dose of intramuscular 20 micrograms. Participants were 359 healthy medical and nurse students randomly allocated to one of the three groups: Group I-IM 20 micrograms; Group II-IM 10 micrograms; Group III-ID 2 micrograms at 0, 1 and 6 months. Anti-HBs titres were measured after complete vaccine schedule by ELISA/Pasteur. Baseline variables were similar among groups and side effects were mild after any dose. Vaccines in the IM-10 micrograms group had seroconversion rate and geometric mean titre (GMT 2344 IU L-1), not significant different from the IM-20 micrograms group (GMT 4570 IU L-1). On the contrary, 21.4% of the ID-2 micrograms recipients mount antibody concentration below 10 IU L-1 and GMT of 91 IU L-1, a statistically significant difference compared with the standard schedule IM-20 micrograms (p < 0.001). A three dose regimen of half dose IM could be considered an appropriate schedule to prevent hepatitis B in young health adults which is of relevance to the expansion of hepatitis B vaccine programme.

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.

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

To determine the duration of antibody after low-dose, intradermal (i.d.), plasma-derived hepatitis B vaccination and the response to a booster dose, we studied two classes of medical students who were immunized with 2 micrograms doses i.d. In one class, 73/88 (85%) who had been immunized by skilled personnel at 0, 1 and 6 months, had protective concentrations (greater than or equal to 10 mIU ml-1) of anti-HBs at 20 months after the first dose. Twelve (92%) out of 13 students who received only two doses at 0 and 1 months also had protective concentrations at month 20. At month 27, 11/16 (69%) with antibody less than or equal to 10 mIU ml-1 responded to a fourth dose of 2 micrograms i.d. with protective concentrations of anti-HBs. In the second class, after three doses of vaccine at 0, 1, and 6 months, protective concentrations of anti-HBs were present in 90/93 (97%) at 14 months and in 71/80 (89%) at 25 months. In those who received only two doses, protective concentrations were found in 24/31 (74%) at 14 months and 9/16 (56%) at 25 months. After a booster dose of 2 micrograms i.d. at month 25, anti-HBs concentrations rose from a geometric mean of 78 to 1198 mIU ml-1 in 60 subjects previously immunized with three doses and from 18 to 1054 mIU ml-1 in 16 students previously immunized with only two doses. Overall, 73/76 (96%) of students in the second group had protective concentrations of antibody after the booster dose.(ABSTRACT TRUNCATED AT 250 WORDS)