Three-week hepatitis B vaccination provides protective immunity

Sero-prevalence of hepatitis B virus and compliance with hepatitis B vaccination schedules among outpatient clinic attendees in Nairobi

BACKGROUND

Hepatitis B is becoming a growing public health problem in Kenya. To combat the threat, HBV vaccination should be recommended, particularly for individuals who are not covered by the national immunization program. Vaccination provides sero-protection rates approaching 95% among healthy adults after completing the three-dose vaccination course, but decreases to 87% among those who receive only two doses, emphasizing the importance of completing the three-dose vaccination course. However, data on adult adherence to HBV multi-dose vaccines in Sub-Saharan Africa are limited, despite the fact that this information is critical for prevention. As a result, more research on HBV vaccine dose completion is required. The purpose of this study is to estimate the prevalence of hepatitis B virus infection among out-patient clinic attendees in Nairobi, Kenya, as well as to identify beneficiaries of free vaccination and barriers to completing the recommended vaccine doses.

METHODS

Between July 30th and September 30th, 2015, 2644 outpatient clinic attendees aged ≥ 4 were recruited from three hospitals in Nairobi County, Kenya: Mama Lucy, Riruta, and Loco. Self-administered questionnaires were used to collect socio-demographic information, and blood samples were tested for hepatitis B surface antigen (HBsAg) using the KEMRI HEPCELL Rapid® (Hepatitis B Detection kit) test kit. Individuals who tested negative for HBsAg were given a free course of three doses of HBV vaccine. The vaccination register provided information on the number of doses administered.

RESULTS

The average age of the study population was 31.4 years (range: 4-66), with females accounting for 59.2%. 1.82% (48/2644) of the participants tested positive for HBsAg. Among the 2596 individuals eligible for vaccination, 66% (1720/2596) received at least one dose, and 51.8% (1345/2596) received all three doses. Vaccination acceptance increased with age, with older patients more likely to return for subsequent dose (OR>1 for second and third dose). Unavailability and failure to contact client were cited as significant (p<0.0001) barrier to vaccination completion by 53.7% (666/1226, 95% CI 0.5-0.6) and 37% (454/1226, 95% CI 0.3-0.4) of respondents respectively.

CONCLUSION

The prevalence of HBV infection among outpatient clinic attendees highlights the importance of expanding HBV immunization programs in Kenya. However, given the low vaccination completion rate, there is a need for public awareness of the vaccine's importance in preventing HBV and HBV-related complications.

Getting the shots: methods to gain adherence to a multi-dose vaccination program for inner city, drug-involved prostitution communities

Street-based sex-work and poly-substance drug use, coupled with low vaccination rates and limited utilization of the mainstream health care system, put the sex worker communities of Bogotá's city center at extreme risk of infection with the hepatitis B virus (HBV). Vaccination is critical to maintaining low prevalence of the disease and low incidence of new cases, yet the floating and inconsistent nature of Bogotá's drug-involved female and transsexual prostitution communities make it difficult to complete a 3-dose vaccination program. Between December 2011 and March of 2012, the Fénix Foundation collaborated with the Bogotá Health Department to deliver free HBV vaccines to this vulnerable population. This paper outlines methods used in the vaccination program to generate a 37.7% adherence rate, significantly higher than that previously reported for HBV vaccination programs also targeting marginalized populations. This program's practices are based on the Fénix peer leader method, and are offered as a model that can be applied to other health interventions operating in analogous contexts, with similarly high-risk populations.

A randomised controlled trial of financial incentives to increase hepatitis B vaccination completion among people who inject drugs in Australia

OBJECTIVE

This study aimed to investigate the efficacy of modest financial incentives in increasing completion of an accelerated 3-dose hepatitis B virus (HBV) vaccination schedule (0, 7, 21days) among people who inject drugs (PWID).

METHODS

Randomised controlled trial. Participants were randomly allocated to receive $30 Australian Dollars cash following receipt of vaccine doses two and three ('incentive condition'), or standard care ('control condition'). Serologically confirmed HBV-susceptible PWID. Two inner-city health services and a field study site in Sydney, Australia. The primary outcome was completion of the vaccination series. Additional assessments included self-reported demographic, drug use and treatment, and risk-taking histories.

RESULTS

Compared to the control condition, significantly more participants in the incentive condition received all three vaccine doses, under intention-to-treat analyses (n=139; 87% versus 66%; p=.004); and within the specified window periods under per protocol analyses (n=107 received three vaccine doses; 92% versus 67%; p=.001). Multivariate analysis indicated that the incentive condition and longer injecting histories significantly increased the likelihood of series completion. Aboriginal/Torres Strait Islanders were significantly less likely to complete the series.

CONCLUSIONS

Modest financial incentives, per-dose, increased adherence to the accelerated HBV vaccination schedule among PWID. Results have implications for increasing HBV and, potentially, other vaccine-preventable infections, among PWID.

Rapid immunization scheme for spouses of individuals estabilished as hepatitis B carriers during premarital tests

BACKGROUND

The aim of this study was to monitor the cases identified as hepatitis B carriers during premarital tests, to vaccinate their prospective spouses with a rapid vaccination scheme, and to compare the anti-HBs responses with the traditional vaccination scheme.

METHODS

Blood samples of 1250 couple spouses were tested for HBsAg and anti-HBs. HBsAg positive cases' fiancées which were found HBV negative were administered a rapid three-dose vaccination scheme on days 0, 7, and 21. Forty controls with similar age and gender were also were administered three doses of the same vaccine.

RESULTS

Out of 1250 cases (625 couples), 46 (3.6%) were HBsAg positive, and 40 of them aged between 18 and 39 were admitted to the rapid vaccination program.

CONCLUSION

Upon determination of HBsAg positivity in premarital tests, a rapid vaccination program provides early protection, but the 6th and 12th month vaccinations are also required. Anti-HBs response should be monitored.

Liver disease in adolescents: A cohort study of high-risk individuals

Little is known about the health and behavior of adolescent offenders as they relate to abnormalities of liver biochemistry and hepatitis C virus (HCV) infection. A large study of male juvenile offenders was undertaken that allowed a re-evaluation of the normal limits of alanine aminotransferase (ALT), associations with elevated ALT, and HCV antibody positivity. Young offenders (age 12-19 years) serving community orders participated in a wide-ranging health survey and laboratory assessment between October 2003 and December 2005. Normal ranges for liver biochemistry were calculated from the 95th percentile of males at the lowest risk for liver disease. The final sample comprised 682 males, of whom 439 (64%) gave blood. The calculated upper limit of normal for ALT was 28 IU/L. Seventeen percent of adolescents had an elevated ALT. Strong associations with elevated ALT included HCV antibody positivity [odds ratio (OR) 14.6], overweight and obesity (OR 6.9), and elevated total cholesterol (OR 3.6). More than 90% of adolescents with elevated ALT levels had 1 or more features of the metabolic syndrome. HCV antibody was positive in approximately 3% of the cohort, with the most significant risk factor being injecting drug use (OR 7.8; P < 0.01). The new infection rate was 3.7% per year.

CONCLUSION

New upper limits for ALT provide greater sensitivity for the early diagnosis of liver disease in adolescents. High rates of HCV infection and obesity-related liver disease exist in this group, and targeted interventions are needed to reduce future health-related morbidity.

An accelerated hepatitis B vaccination schedule for young drug users

OBJECTIVE

To determine completion rates for an accelerated hepatitis B vaccine (HBV) program among a population of young drug users.

DESIGN

Between January 2001 and May 2002, a three-dose course of HBV vaccine (0, 7 and 21 days) was offered free to all drug users (aged 22 years or younger) accessing two outreach sites of a youth-focused support and drug treatment service in metropolitan Melbourne, Australia. Clients were offered vaccination in any safe environment of their choice. An audit was conducted on the health records of participating clients.

MAIN OUTCOME MEASURES

Number of completed vaccinations; settings in which vaccinations were completed.

RESULTS

Ninety young people accepted vaccination, with 71% completing the full course. The majority preferred to receive vaccination at drug treatment outreach sites (53%).

CONCLUSIONS

An accelerated vaccination schedule appears acceptable to young drug users, suggesting that vaccination programs can be successful when barriers to immunisation are appropriately identified and addressed.

Predictors of completion of a hepatitis B vaccination schedule in attendees at a primary health care centre

BACKGROUND

In Australia, rates of hepatitis B (HBV) transmission continue to be higher in certain populations, including commercial sex workers and injecting drug users (IDU). This study aims to identify rates and predictors of completion of a HBV vaccination schedule in 'high-risk' attendees of a primary health care centre in Sydney.

METHODS

All clients who attended Kirketon Road Centre, a primary health care centre located in Kings Cross, Sydney, with no evidence of HBV immunity were included in the cohort. The study design was observational with historical controls. The main outcome measure was completion of a three-dose HBV vaccine schedule in the study period.

RESULTS

Among 2085 clients who received a first vaccination, 1013 (49%) received a second and 435 (21%) received a third vaccination. Univariate analysis found that significant predictors of completion of the vaccine schedule were intention to administer an accelerated schedule (OR 1.49, P = 0.004), not being an IDU (OR 1.29, P = 0.02) and shorter time between first visit and first vaccine dose (OR 1.24, P for trend <0.0001); however, on multivariate analysis, not being an IDU was no longer a predictor of vaccine completion.

CONCLUSION

Implementation of an accelerated vaccination schedule improved completion rates but they were still low, despite the provision of free vaccination in a service specifically targeting the needs of sex workers, IDU and other marginalised populations. Increasing HBV vaccine uptake and completion rates in Australian adults is an important public health issue not only for the prevention of HBV but also for the future application of other potential vaccines, including those against HIV and hepatitis C.

Twinrix®vaccination schedules among injecting drug users

Twinrix is the only licensed vaccine that provides dual protection against infection with hepatitis A virus (HAV) and hepatitis B virus (HBV). The standard vaccination schedule for Twinrix is 0, 1 and 6 months. However, many high-risk populations, such as injecting drug users (IDUs), do not complete the vaccination series and, thus, do not acquire sufficient immunity against HAV and HBV. Twinrix can be administered using an accelerated vaccination schedule of 0, 7 and 21 days, with a booster recommended at 12 months. This manuscript reviews the available literature on vaccinating IDUs against HAV and HBV. The authors conclude that there is insufficient evidence regarding whether the accelerated Twinrix HAV/HBV vaccination schedule would yield a greater number of IDUs protected against both HAV and HBV.

Comparison of the accelerated and classic vaccination schedules against Hepatitis B: three-week Hepatitis B vaccination schedule provides immediate and protective immunity

Background

Hepatitis B virus infection although preventable by vaccination remains an important health issue throughout the world due to its morbidity, mortality and economical losses. Early seroprotection is desirable for people at high risk of exposure. The aim of this study was to determine whether three-week hepatitis B vaccination (on days 0, 10 and 21) provide seroprotection or not.

Methods

The 120 subjects enrolled into the study were divided into two groups and vaccinated by the classic (months 0, 1, and 2) or the accelerated (days 0, 10, and 21) schedules and antibody response determined on days 30, 60, and 90 and, if below 10 mIU/ml^-1, again on day 180. For each individual in the classic group (B) three subjects were enrolled in the accelerated group (A). Recombinant hepatitis B vaccine (Gen-Hevac B, Pasteur) was given as 20 micrograms intramuscular injections via the deltoid muscle. A booster dose on day 365 was administered for each group. Family members of hepatitis B carriers and volunteer health personnel were enrolled into group A. To the B group only volunteers who wanted vaccination against hepatitis B were included.

Results

After three doses of vaccine, Anti-HBs titers reached protective levels in both groups. The number of vaccinees with seroprotective levels of Anti-HBs (≥10 mIU/ml^-1) on day 30 was 53 (58.9%) in group A and 9 (30.0%) in group B (p < 0.05). On day 60, there was no difference between group A and B, with response rates of 84.4% (n = 76) and 80.0% (n = 24) respectively (p > 0.05). On day 90 there was no difference between group B and group A; with 26 (86.7%) and 79 (87.7%) responders respectively. In both groups those with Anti-HBs levels <10 mIU/ml^-1 attained protective levels by day 180.

Conclusion

In this study, the three-week vaccination provided protective antibody titers within a shorter time compared to the classic schedule. Therefore, in order to provide rapid antibody production against hepatitis B virus, the accelerated vaccination schedule seems to be a good preference.

A novel hepatitis B vaccination regimen for adolescents: two doses 12 months apart

BACKGROUND

Two- and three-dose hepatitis B vaccinations for adolescents are usually administered using dosing schedules of 6 months duration. This does not suit all circumstances. A 12-month schedule would be useful in schools and settings where only annual vaccination is the most practical option.

AIM

To examine the efficacy of a 12-month dosing interval for two-dose hepatitis B vaccination of adolescents.

SUBJECTS

Four hundred and fifty-eight healthy first-year high school (Year 7) students. VACCINATION REGIMEN: Engerix-B (GlaxoSmithKline Biologicals) 20 micro g: two doses, 12 months apart. SERUM COLLECTION: #1, same day as first vaccine dose given; #2, >1 month after second vaccine dose.

RESULTS

Of the 458 children: 15 did not provide serum #1, 17 had prior vaccination, 2 had prior infection, 18 moved, 7 failed to provide serum #2, 12 withdrew (only 1 cited vaccine adverse reactions as the reason). Three hundred and eighty-seven (210 males, 177 females) aged 11.8-14.2 years (mean: 12.9+/-0.42 years) at entry completed both injections 321-381 days (mean: 359+/-10.7 days) apart and supplied serum #2, 30-57 days (mean: 41+/-5.6 days) after the second vaccine dose.Anti-HBs responses: 379 of the 387 subjects (97.9%; 95% CI: 95.9-99.1%) achieved anti-HBs > or =10 mIU/ml (range 10-170,460 mIU/ml, geometric mean concentration (GMC) 4155 mIU/ml-95% CI of mean: 3381-5106 mIU/ml). Sex was the only determinant of anti-HBs concentration (206 males: GMC 3073 mIU/ml-95% CI: 2285-4134 mIU/ml; 173 females: GMC 5944 mIU/ml-95% CI: 4508-7851 mIU/ml; P=0.001).

CONCLUSION

A high seroprotection rate and GMC were achieved using two 20 micro g doses of Engerix-B administered 12 months apart. These results are similar to those achieved by others using 6-month three- and two-dose regimens in adolescents.

Accelerated hepatitis B vaccination schedule in childhood

BACKGROUND

For children travelling to a hepatitis B virus (HBV) endemic area or before a treatment by blood or blood productions, the conventional HBV vaccination schedule takes too long to be completed. There may be problems in the completion of the whole vaccination schedule in developing countries because of particular problems. In these situations an accelerated schedule may be useful for HBV vaccination.

METHODS

In this study, 40 children were randomly divided into two groups. Groups were vaccinated according to two different schedules; schedule A: one dose at 0, 1, and 6 months and schedule B: one dose at 0, 10, and 21 days (Engerix B, 10 mcg/0.5 ml, GlaxoSmithKline). Follow-up blood samples were obtained at 1, 6 and 12 months after the first vaccine injection.

RESULTS

Seroconversion rates were 35 and 80% 1 month after the first vaccine injection, 95 and 80% at 6 months, 95 and 100% at 12 months, in groups A and B respectively. Seroprotection rates were 20 and 65% 1 month after the first vaccine injection, 85 and 70% at 6 months, 95 and 95% at 12 months, in groups A and B respectively. Seroconversion and seroprotection rates was significantly different at day 28 in accelerated vaccination schedule (P < 0.005).

CONCLUSIONS

In conclusion, an accelerated vaccination course against HBV (three doses at 0, 10, and 21 days) elicited protective levels of anti-HBs antibodies more rapidly than a classic course (three doses at 0, 1, and 6 months) and without a difference in the rate of seroprotection after 1 year. The accelerated 3-week recombinant HBV vaccination schedule should be recommended for HBV prophylaxis when children, such as hurried travellers, who have to have blood and blood productions, or an estimated irregular vaccination, where they have < 1 month to complete the standard HBV vaccination schedule before travelling to HBV endemic areas.

A new accelerated vaccination schedule for rapid protection against hepatitis A and B

BACKGROUND

Increasing travel stresses the requirement for rapid protection against infections such as hepatitis A and B.

METHODS

This randomised, multicentre study investigated an accelerated vaccination schedule using a combined hepatitis A and B vaccine (Twinrix, Smithkline Beecham Biologicals) compared with simultaneous administration of the two corresponding monovalent vaccines. The combined vaccine was administered on days 0, 7 and 21, whereas the comparison group received hepatitis A vaccine on day 0 and hepatitis B vaccine on days 0, 7 and 21. All subjects received booster vaccination at month 12.

RESULTS

At month 1, 100% of subjects in the combined group and 99% of the controls were seropositive for anti-HAV antibodies. The corresponding seroprotection rates for anti-HBs antibodies were 82.0 and 83.9%, respectively. Examination of the 95% confidence intervals (CIs) for the treatment differences showed the two vaccines to be equivalent in terms of immunogenicity 1 week after the initial vaccination course. Just prior to the booster, the seropositivity rate for anti-HAV was 96.2% in the combined group and 95% in the control group. For anti-HBs, this was 94 and 91.6%, respectively. All subjects were seropositive for anti-HAV and seroprotected against hepatitis B at month 13. The anti-HAV GMCs were 9571mIU/ml with the combined vaccine and 5206mIU/ml in control subjects. The anti-HBs titre was 26002 and 29,196mIU/ml, respectively. Both groups had a similar reactogenicity profile.

CONCLUSIONS

The accelerated schedule of the combined vaccine provides a good immune response against hepatitis A and B antigens and is suitable for last minute immunisation.

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

To study early seroconversion rates after hepatitis B vaccination intramuscular (i.m.) and low-dose intradermal (i.d.) vaccination was compared when given either according to the registered 0, 4, 8 weeks scheme (scheme A), or to an accelerated 0, 2, 6 weeks scheme (scheme B). Medical staff received either 2 microg i.d. or 20 microg i.m. of a recombinant hepatitis B vaccine, in a non-randomized open trial. Two weeks after the third dose i.m. vaccinees overall had significantly higher rates of protective anti-HBs levels (anti-HBs > or = 10 IU/I), (23/30, 77%) compared with i.d. vaccinees (75/166, 45%) (p < 0.001). We conclude that when rapid protection against hepatitis B virus (HBV) infection is desirable, such as for post-exposure prophylaxis, an accelerated low-dose i.d. vaccination schedule cannot be used.

Accelerated schedule of hepatitis B vaccination in liver transplant candidates

Liver transplantation has become the treatment of choice worldwide for many patients with end-stage liver disease. In terms of survival and quality of life, the results of the procedure in many centers are very good. However, the long-term function of the grafts may be affected by vascular, immunologic, or infection problems, the latter being a major cause of morbidity and mortality after orthotopic liver transplantation (OLT). Therefore, prophylactic vaccination against hepatitis B virus (HBV) infection is recommended in patients awaiting liver transplantation. Individuals with chronic advanced liver disease are known to be less responsive to HBV vaccination. On the other hand, the widely recommended standard schedule (months 0, 1, and 6) for immunization against hepatitis B takes 6 months, a regimen which may not be completed in time prior to OLT or which may not be completed due to noncompliance, possible reasons for the lower rates of seroprotection in OLT candidates. Studies show that, in principle, complete immunization with an accelerated hepatitis B vaccination protocol (0, 7, 21 days) induces early seroprotection with excellent seroprotection rates and anti-HBs titers in immunocompetent individuals. We therefore performed a prospective clinical trial to assess immunogenicity and reactogenicity of this accelerated vaccination regimen in OLT candidates compared to healthy controls.

Evaluation of B and T-cell responses in chimpanzees immunized with Hepagene, a hepatitis B vaccine containing pre-S1, pre-S2 gene products

Approximately 5-10% of healthy young adults receiving the commercially available hepatitis B vaccine (either serum derived or recombinant) fail to mount an adequate immune response. This nonresponder rate has prompted the demand for more immunogenic vaccines. An alternative to the currently licensed hepatitis B vaccines is Hepagene, a novel recombinant hepatitis B vaccine containing S, pre-S1 and pre-S2 antigenic components, produced in the mouse C127I clonal cell line after transfection of the cells with genes encoding the three antigens. In this study, chimpanzees were immunized with Hepagene to study the humoral and cellular immune responses to this vaccine. Two out of the three animals immunized with this vaccine seroconverted 4 weeks after their first injection and all of the animals elicited high anti-HBs levels that were maintained for at least 28-30 weeks after their third immunization. The anti-HBs levels elicited in these animals protected them against an experimental challenge with HBV. Peripheral blood mononuclear cells (PBMCs) obtained from immunized animals could be stimulated in vitro by rHBsAg and peptides representing regions within all three of the viral envelope proteins. Additionally, an anti-id that mimics the a determinant in the S-region of HBsAg could also stimulate in vitro proliferation of PBMCs from these immune animals. These results indicate that this new recombinant HBV vaccine encoding all three of the surface antigen proteins is highly immunogenic is that it can stimulate strong cellular and humoral immune responses.

Accelerated Schedule for Hepatitis B Immunization

Background: A considerable number of people remain unprotected against hepatitis B. These people may require immunization at short notice before being exposed to situations or locations where a risk of infection is present. Currently, full active immunization against hepatitis B, when administered according to recommended schedules, takes 2-6 months. This open, randomized multicentric study evaluated the reactogenicity and immunogenicity of a recombinant hepatitis B vaccine in adults when it was administered according to three different rapid vaccination schedules. Methods: Five hundred and twenty four healthy adults (aged 18-59 years) were randomly divided into three groups. Hepatitis B vaccine was given intramuscularly in the deltoid muscle at months 0, 1, and 2 (group A); weeks 0, 14, and 28 (group B); and weeks 0, 7, and 21 (group C). Symptoms were recorded by the subjects on individual diary cards. AntiHBs were measured using radioimmunoassay (Ausab-Abbott); a seroprotective titer was defined as 10 IU/L. Results: At day 28, no significant difference in seroprotection rates (SPRs) i.e., seroconversion >= 10 IU/L,was observed, between groups B (55.6%) and C (65.2%), but both these groups had significantly greater SPRs than group A (15.0%). Although not significant (p=.07), groups B and C also had higher SPRs than group A (78.5% and 76.4% versus 65%) at day 56. One month after completing the three dose schedules, the SPRs were as follows: 89.0% (group A); 78.5% (group B); and 76.4% (group C), increasing to > 94% at month 7 to 8 in all three groups. The SPRs at month 13 were 95.8%, 98.9%, and 98.6%, respectively. Among the three groups, no significant differences were observed from month 2 onwards in either SPRs or geometric mean titers. In groups A, B, and C, 3.7%, 5.0%, and 7.1% of the vaccine injections were associated with local symptoms. Also 8.3%, 6.2%, and 6.3% of subjects exhibited general symptoms following each vaccine dose; all symptoms were transient and resolved spontaneously. Conclusions: This recombinant hepatitis B vaccine administered at weeks 0, 7, 21, or at weeks 0, 14, 28, rapidly elicits high rates of seroprotection, which persist at least until month 12.