The anti-HBs response after 2 different accelerated intradermal and intramuscular schemes for hepatitis B vaccination

Fractional dose of intradermal compared to intramuscular and subcutaneous vaccination - A systematic review and meta-analysis

BACKGROUND

Vaccine supply shortages are of global concern. We hypothesise that intradermal (ID) immunisation as an alternative to standard routes might augment vaccine supply utilisation without loss of vaccine immunogenicity and efficacy.

METHODS

We conducted a systematic review and meta-analysis searching Medline, Embase and Web of Science databases. Studies were included if: licensed, currently available vaccines were used; fractional dose of ID was compared to IM or SC immunisation; primary immunisation schedules were evaluated; immunogenicity, safety data and/or cost were reported. We calculated risk differences (RD). Studies were included in meta-analysis if: a pre-defined immune correlate of protection was assessed; WHO-recommend schedules and antigen doses were used in the control group; the same schedule was applied to both ID and control groups (PROSPERO registration no. CRD42020151725).

RESULTS

The primary search yielded 5,873 articles, of which 156 articles were included; covering 12 vaccines. Non-inferiority of immunogenicity with 20-60% of antigen used with ID vaccines was demonstrated for influenza (H1N1: RD -0·01; 95% CI -0·02, 0·01; I2 = 55%, H2N3: RD 0·00; 95% CI -0·01, 0·01; I2 = 0%, B: RD -0·00; 95% CI -0·02, 0·01; I2 = 72%), rabies (RD 0·00; 95% CI -0·02, 0·02; I2 = 0%), and hepatitis B vaccines (RD -0·01; 95% CI -0·04, 0·02; I2 = 20%). Clinical trials on the remaining vaccines yielded promising results, but are scarce.

CONCLUSIONS

There is potential for inoculum/antigen dose-reduction by using ID immunisation as compared to standard routes of administration for some vaccines (e.g. influenza, rabies). When suitable, vaccine trials should include an ID arm.

Cutaneous delivery of prophylactic and therapeutic vaccines: historical perspective and future outlook

The skin has long been recognized as an attractive target for vaccine administration. A number of clinical studies have tested the epidermal and dermal routes of delivery using a variety of vaccines over the years. In many cases, cutaneous administration has been associated with immunological benefits, such as the induction of greater immune responses compared with those elicited by conventional routes of delivery. Furthermore, there is a growing body of evidence to suggest that such benefits may be particularly important for certain higher-risk populations, such as the elderly, the immunocompromised and cancer patients. Despite the potential advantages of vaccination via the skin, results have sometimes been conflicting and the full benefits of this approach have not been fully realized, partly due to the lack of delivery devices that accurately and reproducibly administer vaccines to the skin. The 5-year outlook, however, appears quite promising as new cutaneous delivery systems advance through clinical trials and become available for more widespread clinical and commercial use.

Hepatitis B vaccines

Immunization is the most effective way to prevent transmission of HBV and, hence, the development of acute or chronic hepatitis B. The national strategy to eliminate transmission of the virus in the United States includes vaccination of all newborn infants, children, adolescents, and high-risk adults. Postexposure prophylaxis is also advocated, depending on the vaccination and anti-HBs status of the exposed person. Seroprotection after vaccination, defined as anti-HBs > or = 10 mIU/mL, is achieved in over 95% of all vaccinees. The hepatitis B vaccines are very well tolerated with usually minimal adverse effects. Predictors of non-response include increasing age, male gender, obesity, tobacco smoking, and immunocompromising chronic dis-ease. For those who remain nonresponders after the second series of vaccination, adjuvants such as GM-CSF may be considered, but their results are variable.

Schedules for hepatitis B vaccination of risk groups: balancing immunogenicity and compliance

INTRODUCTION

Vaccination is an important tool in hepatitis B prevention. However, several vaccine doses are required to induce long-term protection. Several at-risk groups have difficulties in adhering to the standard vaccination schedule.

OBJECTIVES

This paper aims to review the use of accelerated hepatitis B vaccination schedules, in terms of immunogenicity and compliance.

RESULTS

Accelerated schedules (0.1.2.12 months) or super-accelerated schedules (0.7.21.360 days) have been shown to result in higher proportions of healthy vaccinees reaching anti-HBs antibody levels >or=10 IU/l more rapidly. A fourth completing dose is required to lift antibody levels to an equal height, as does a standard (0.1.6 months) schedule. Accelerated schedules do also increase the uptake of hepatitis B vaccine, that is the proportion of vaccinees who receive three doses. However, completing the schedule with a fourth dose is usually more difficult than completing a standard 0.1.6-month schedule. Several additional tools can help to increase the compliance (eg, reminder systems, outreach services and incentive schemes).

CONCLUSION

For rapid seroconversion and almost immediate protection in the short term, a (super)accelerated schedule could be used in at-risk groups. As long-term protection data with these (super) accelerated schedules have not been documented yet, a fourth dose at month 12 is still required. A shortened schedule (0.1.4 months) might be an alternative worth considering compared with the standard 0.1.6, as it convenes to internationally accepted minimum dose intervals and offers earlier protection. There is a clear need to study the long-term protection and effectiveness of the primary part of (super)accelerated schedules.

Adherence to hepatitis B virus vaccination at syringe exchange sites

Injection drug users (IDUs) are at high risk for hepatitis B virus (HBV); however, they often do not receive preventive vaccination. IDUs who use mobile health care services linked to a syringe exchange program in New Haven were routinely screened for HBV, hepatitis C virus, and syphilis. Individuals without prior exposure to HBV were offered three-part vaccination series. Of the 212 IDUs screened for HBV infection, 134 (63%) were eligible (negative for HBV surface and core anti-bodies) for vaccination and 10 (4.7%) had evidence of chronic HBV infection. Compared to those with previous exposure to HBV, vaccine-eligible patients were significantly more likely to be younger and use heroin and less likely to be black, home-less, daily injectors, and cocaine users. Of the 134 vaccine-eligible subjects, 103 (77%) and 89 (66%) completed two and three vaccinations, respectively. Correlates of completing all three vaccinations included older age (OR = 1.06, 95% CI = 1.04-1.07), injecting daily (OR = 2.12, 95% CI = 1.36-6.73), and being homeless (OR = 1.98, 95% CI = 1.14-12.27). These results suggest that IDUs remain at high risk for acquiring HBV infection. Programs that link health care to a syringe exchange program are effective ways to provide preventive health care services to IDUs, particularly HBV vaccination. Trust engendered by and mutual respect afforded by such programs result in repeated encounters by active IDUs over time.

Hepatitis B vaccines

Immunization is the most effective way to prevent transmission of HBV and, hence, the development of acute or chronic hepatitis B. The national strategy to eliminate transmission of the virus in the United States includes vaccination of all newborn infants, children, adolescents, and high-risk adults. Postexposure prophylaxis is also advocated, depending on the vaccination and anti-HBs status of the exposed person. Seroprotection after vaccination, defined as anti-HBs > or = 10 mIU/mL, is achieved in over 95% of all vaccinees. The hepatitis B vaccines are very well tolerated with usually minimal adverse effects. Predictors of non-response include increasing age, male gender, obesity, tobacco smoking, and immunocompromising chronic disease. For those who remain nonresponders after the second series of vaccination, adjuvants such as GM-CSF may be considered, but their results are variable.

Is a low dose of hepatitis B vaccine enough for a rapid vaccination scheme?

AIM: To determine whether or not a low dose of HB vaccine can be effectively used in the rapid vaccination.

METHODS: Rapid vaccination (0, 1, 2 months) with low dose (5 μg) or routine dose (10 μg) HB vaccine was studied in 250 subjects (130 school children and 120 university students). Serum from all the participants was tested for HBsAg, anti-HBs and anti-HBc at 1, 3 and 7 months after the first dose of vaccination and all subjects were serum HBV marks negative before the vaccination. Non-responders to a complete initial vaccination from university students were given an additional vaccination with 10 μg of HB vaccine and their serum anti-HBs was tested again one month later.

RESULTS: One month after the third dose of vaccination (third month) sero-conversion rates and geometric mean titer (GMTs) were significantly (P < 0.01) higher in the routine dose (resp. 89% and 106.8) than in the low dose group (resp. 72% and 59.5). Sero-conversion rates and GMTs were maintained stable for another 4 months in both groups. After an additional vaccination to non-responders with 10 μg HB vaccine, 17/23 subjects (13/15 from those vaccinated with 5 μg vaccine and 4/8 from those vaccinated with 10 μg vaccine) became anti-HBs positive, yielding similar sero-conversion rates for both dose groups.

CONCLUSION: Higher sero-conversion rates and GMTs were reached in those vaccinated with 10 μg HB vaccine than in those vaccinated with 5 μg HB vaccine after a complete vaccination with a 0, 1, 2 month scheme. But the subjects vaccinated with 5 μg vaccine can also reach the similar sero-conversion rate after an additional vaccination.

Intramuscular versus intradermal administration of anti-hepatitis B vaccine in non-cirrhotic hepatitis C patients

Intradermal vaccination has been proposed as an alternative for the administration of anti-hepatitis B vaccine. Patients (n=66) with chronic viral hepatitis C without cirrhosis were randomised into two groups (intramuscular, n=38; and intradermal, n=28) for prospective immunisation with 20 microg recombinant vaccine, using an ultra-rapid schedule (doses at 0, 15 and 30 days). Sero-conversion (antibody level >/=10 mU/ml) in the intramuscular group was reached by 20, 40 and 72% of patients at days 15, 30 and 60 compared to 4, 8 and 36% for the intradermal group (P=0.010 at day 60). Additionally, levels rose more rapidly in the intramuscular group (P=0.004). Our results do not support the use of intradermal route of immunisation against HBV in HCV patients.