Hepatitis A/B vaccine completion among homeless adults with history of incarceration

How nurses contribute to the elimination of hepatitis B? A systematic review and meta-analysis

BACKGROUND

With approximately one-third of the global population exhibiting serological evidence of exposure, the hepatitis B virus remains a serious public health threat. Elimination of hepatitis B faces enormous challenges, from prevention to diagnosis, treatment, and long-term monitoring. Nurses are pivotal in optimising the hepatitis B care continuum; however, their contributions have been neglected.

OBJECTIVE

To identify the role of nurses in the elimination of hepatitis B and to synthesise the effectiveness of interventions with nursing roles in approaching the elimination target.

DESIGN

A systematic review and meta-analysis.

SETTING(S)

Thirteen databases (EMBASE, MEDLINE via OvidSP, Ovid Emcare, Ovid Nursing Database, British Nursing Index, APA PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL, Scopus, Web of Science Core Collection, China National Knowledge Internet, SinoMed, and Wanfang Data) were searched from their inception to 6 December 2022.

METHODS

Interventional studies examining the contribution of nursing roles towards elimination targets were included. Content analysis was used to extract and map the nursing roles based on the nursing interventions classification system. Random-effects meta-analyses were conducted to examine the effectiveness of the intervention in improving hepatitis B screening, detection, and vaccination rates.

RESULTS

The synthesis from 16 studies identified 13 nursing roles that primarily involved (1) health education and counselling for informed patient decision-making regarding hepatitis B prevention, vaccination, screening, and disease monitoring; (2) case management and health promotion to advocate elimination services at multiple levels and enable equitable access among marginalised communities; and (3) running specialist clinics to lead advanced practices in prescribing and carrying diagnostic tests, formulating evidence-based individualised care plans, and coordinating care throughout the disease process. Interventions with these roles achieved pooled hepatitis B screening and detection rates of 64 % (95 % confidence interval [CI] = 0.44, 0.84) and 2 % (95 % CI = 0.00, 0.05), respectively, increased the odds of hepatitis B virus vaccination by 2.61 times (95 % CI = 1.60, 4.28), improved immunity rate, and enhanced patient adherence to antiviral treatment and monitoring of liver comorbidities. However, their effects on hepatitis B virus DNA-negative conversion rates and hepatocellular carcinoma incidence were not significant.

CONCLUSIONS

Nurses play multifaceted roles in advocating hepatitis B screening and vaccination, initiating outreach efforts in marginalised communities, and leading advanced practices that effectively contribute to the elimination of hepatitis B. Policymakers should consider how nurses may help the achievement of the elimination target.

REGISTRATION

PROSPERO (CRD42022380719) registered on December 12, 2022.

TWEETABLE ABSTRACT

Nurses raised awareness, initiated outreach efforts, addressed inequalities, and led advanced practices-effectively contributing to eliminating hepatitis B.

Strategies to improve vaccination rates in people who are homeless: A systematic review

People who are homeless experience higher rates of vaccine-preventable disease, including COVID-19, than the general population, and poorer associated health outcomes. However, delivering vaccinations to people who are homeless is complex, and there is a lack of evidence to inform practice in this area. The aim of this systematic review is to: (a) identify, (b) analyse the characteristics of, and (c) evaluate the outcomes of, strategies to improve vaccination rates in people who are homeless. Literature was retrieved from eight electronic databases. Studies undertaken in high-income countries, published in English, in a peer-reviewed journal, and in full-text were considered. No limits were placed on study design or date. A total of 1,508 articles were retrieved and, after the removal of duplicates, 637 were screened. Twenty-three articles, reporting on nineteen separate vaccination strategies for hepatitis A/B, influenza, herpes zoster, invasive pneumococcal disease, and diphtheria in people who are homeless, were selected for inclusion. All the strategies were effective at improving vaccination rates in, people who are homeless. Most strategies involved vaccination clinics and most were delivered, at least in part, by nurses. Other characteristics of successful strategies included: delivering vaccinations at convenient locations; using accelerated vaccination schedules (if available); vaccinating at the first appointment, regardless of whether a person's vaccination history or serological status were known (if clinically safe); operating for a longer duration; offering training to staff about working with people who are homeless; widely promoting clinics; considering education, reminders, incentives, and co-interventions; ensuring no out-of-pocket costs; and working collaboratively with stakeholders, including people who are homeless themselves. These findings will inform evidence-based vaccination strategies, including for COVID-19, in people who are homeless, and improve associated health outcomes in this at-risk, hard-to-reach group.

Immunogenicity and Safety of a 3-Antigen Hepatitis B Vaccine vs a Single-Antigen Hepatitis B Vaccine: A Phase 3 Randomized Clinical Trial

IMPORTANCE

There is a need for improved immunogenicity of hepatitis B virus (HBV) vaccines among young adults with risk of infection.

OBJECTIVES

To demonstrate manufacturing equivalence of a 3-antigen (3A) HBV vaccine, evaluate noninferiority of seroprotection rate (SPR) of 3A-HBV vs single-antigen (1A) HBV after 2 and 3 vaccine doses, and compare safety and reactogenicity between 3A-HBV and 1A-HBV vaccines.

DESIGN, SETTING, AND PARTICIPANTS

This phase 3, double-blinded, randomized clinical trial included healthy adults aged 18 to 45 years randomized to 1 of three 3A-HBV groups or 1 control group receiving 1A-HBV. The trial was conducted at 37 community clinics and academic hospitals in Canada, Europe, the United Kingdom, and the United States between December 2017 and October 2019. Participants were followed up for 48 weeks after the first vaccination.

INTERVENTIONS

Intramuscular administration of 3A-HBV (10 μg) or 1A-HBV (20 μg) on days 0, 28, and 168.

MAIN OUTCOMES AND MEASURES

Geometric mean concentration (GMC) of serum hepatitis B surface antibodies (anti-HBs) and proportion of participants achieving seroprotection.

RESULTS

Of 2838 participants, 1638 (57.8%) were women, 2595 (91.5%) were White, and 161 (5.7%) were Black or African American. A total of 712 participants (25.1%) were randomized to the 1A-HBV group and 2126 (74.9%) to 3A-HBV. The mean (SD) age at informed consent was 33.5 (8.0) years. The study demonstrated 3A-HBV lot-to-lot consistency, as the 2-sided 95% CIs for each pairwise comparison for the anti-HBs GMC ratios were within 0.67 and 1.50 (eg, adjusted GMC ratio, lot A vs lot B: 0.82; 95% CI, 0.67-1.00; lot A vs lot C: 0.95; 95% CI, 0.78-1.15; lot B vs lot C: 1.16; 95% CI, 0.95-1.41). The SPR of the pooled 3A-HBV was noninferior to 1A-HBV and higher than 1A-HBV after 2 vaccinations at day 168 (90.4% [95% CI, 89.0%-91.8%] vs 51.6% [95% CI, 47.5%-55.6%]) and 3 vaccinations at day 196 (99.3% [95% CI, 98.7%-99.6%] vs 94.8% [95% CI, 92.7%-96.4%]). The mean GMC of anti-HBs with 3A-HBV was 7.9 times higher after 2 vaccinations at day 168 and 3.5 times higher after 3 vaccinations at day 196 compared with 1A-HBV (after 2 vaccinations, 3A-HBV: GMC, 118.7 mIU/mL; 95% CI, 108.0-129.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: GMC, 15.0 mIU/mL; 95% CI, 12.9-17.5 mIU/mL; SE, 1.0 mIU/mL; after 3 vaccinations, 3A-HBV: GMC, 5442.4 mIU/mL; 95% CI, 4967.0-5963.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: 1567.2 mIU/mL; 95% CI, 1338.0-1834.0 mIU/mL; SE, 1.0 mIU/mL). Rates of local and systemic reactogenicities were higher with 3A-HBV compared with 1A-HBV (local: 1805 of 2124 [85.0%] vs 469 of 712 [65.9%]; systemic: 1445 [68.0%] vs 428 [60.1%]). Vaccine discontinuation due to adverse events (AE) was uncommon, and serious AEs were infrequent, reported in 42 participants (2.0%) and 3 participants (0.4%) in the 3A-HBV and 1A-HBV groups, respectively.

CONCLUSIONS AND RELEVANCE

In this study, consistently higher antibody concentrations and SPRs were found with 3A-HBV after 2 and 3 doses vs 1A-HBV in adults aged 18 to 45 years old. The safety and efficacy of 3A-HBV shows its usefulness for the prevention of hepatitis B in young healthy adults.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03408730; EU Clinical Trials Number: 2017-001820-22.

A Nurse Case Management HIV Prevention Intervention (Come As You Are) for Youth Experiencing Homelessness: Protocol for a Randomized Wait-list Controlled Trial

Background

Youth experiencing homelessness are more likely than housed youth to experience premature death, suicide, drug overdose, pregnancy, substance use, and mental illness. Yet while youth experiencing homelessness are 6 to 12 times more likely to become infected with HIV than housed youth, with HIV prevalence as high as 16%, many do not access the prevention services they need. Despite adversities, youth experiencing homelessness are interested in health promotion programs, can be recruited and retained in interventions and research studies, and demonstrate improved outcomes when programs are tailored and relevant to them.

Objective

The study aims to compare the efficacy of a nurse case management HIV prevention and care intervention, titled Come As You Are, with that of usual care among youth experiencing homelessness aged 16 to 25 years.

Methods

The study is designed as a 2-armed randomized wait-list controlled trial. Participants (n=450) will be recruited and followed up for 9 months after the intervention for a total study period of 12 months. Come As You Are combines nurse case management with a smartphone-based daily ecological momentary assessment to develop participant-driven HIV prevention behavioral goals that can be monitored in real-time. Youth in the city of Houston, Texas will be recruited from drop-in centers, shelters, street outreach programs, youth-serving organizations, and clinics.

Results

Institutional review board approval (Committee for the Protection of Human Subjects, University of Texas Health Science Center at Houston) was obtained in November 2018. The first participant was enrolled in November 2019. Data collection is ongoing. To date, 123 participants have consented to participate in the study, 89 have been enrolled, and 15 have completed their final follow-up.

Conclusions

There is a paucity of HIV prevention research regarding youth experiencing homelessness. Novel and scalable interventions that address the full continuum of behavioral and biomedical HIV prevention are needed. This study will determine whether a personalized and mobile HIV prevention approach can reduce HIV risk among a hard-to-reach, transient population of youth at high risk.

International Registered Report Identifier (IRRID)

DERR1-10.2196/26716

Mobile-Enhanced Prevention Support Study for Men Who Have Sex With Men and Transgender Women Leaving Jail: Protocol for a Randomized Controlled Trial

Background

Men who have sex with men (MSM) and transgender women, particularly those who have experienced criminal justice involvement, have particularly high HIV burdens, and a majority of those in jail have substance use disorders (SUDs). MSM and transgender women also experience elevated rates of incarceration. Once community re-entry occurs, individuals are in a critical period for addressing potential risks of HIV and sexually transmitted infection (STI) acquisition and negative sequelae of substance use. Further, the impact experienced by one’s social and sexual networks experienced at the time of detention and release have important health implications for MSM and transgender women.

Objective

The purpose of this study is to test a new intervention—Mobile-Enhanced Prevention Support (MEPS)—that involves a GPS-based mobile app called GeoPassport (referred to as GeoPass in practice), incentives, and peer support for promoting HIV prevention, substance use treatment, and use of related services.

Methods

A two-arm, unblinded, randomized controlled trial will seek to enroll 300 HIV-negative MSM and transgender women, aged 18-49 years, with SUDs, who are either in jail or have recently left jail. Participants will be enrolled by study staff and randomized to the MEPS intervention group or usual care group. The intervention group will receive customized wellness goals in addition to GeoPass, cash incentives, and the support of a trained peer mentor for 6 months. Data collection will consist of a baseline survey and three follow-up surveys at 3, 6, and 9 months postenrollment, either in person or by phone or videoconference when necessary. The primary outcomes include establishing a primary care provider; being prescribed and adhering to pre-exposure prophylaxis (PrEP) for HIV; screening for HIV, STIs, and hepatitis C virus; and engagement in recommended treatment for SUDs. Secondary outcomes include obtaining treatment for any identified infections and avoiding recidivism.

Results

Enrollment began in November 2019 and study completion is expected in 2023.

Conclusions

This study will advance our knowledge base on patient navigation and peer mentor interventions. Peer navigation services have been studied for the treatment of HIV, but less often in the context of HIV and STI prevention among sexual and gender minority populations at the time of re-entry into the community from jail. The MEPS study will examine the acceptability and feasibility of combining peer mentor services with a mobile app to facilitate service utilization and participant–peer mentor communication. MEPS will assess patterns of PrEP uptake and utilization in MSM and transgender women leaving jail. The study will provide heretofore unavailable data from persons leaving jail regarding HIV PrEP, STI screening, substance abuse treatment, and service utilization patterns and experiences, including geocoded data for those in the intervention arm.

Trial Registration

ClinicalTrials.gov (NCT04036396); https://www.clinicaltrials.gov/ct2/show/NCT04036396

International Registered Report Identifier (IRRID)

PRR1-10.2196/18106

Co-Administration of Injected and Oral Vaccine Candidates Elicits Improved Immune Responses over Either Route Alone

Infectious diseases continue to be a significant cause of morbidity and mortality, and although efficacious vaccines are available for many diseases, some parenteral vaccines elicit little or no mucosal antibodies which can be a significant problem since mucosal tissue is the point of entry for 90% of pathogens. In order to provide protection for both serum and mucosal areas, we have tested a combinatorial approach of both parenteral and oral administration of antigens for diseases caused by a viral pathogen, Hepatitis B, and a fungal pathogen, Coccidioides. We demonstrate that co-administration by the parenteral and oral routes is a useful tool to increase the overall immune response. This can include achieving an immune response in tissues that are not elicited when using only one route of administration, providing a higher level of response that can lead to fewer required doses or possibly providing a better response for individuals that are considered poor or non-responders.

Adherence to hepatitis A and hepatitis B multi-dose vaccination schedules among adults in the United Kingdom: a retrospective cohort study

BACKGROUND

Timely and complete vaccination with multi-dose schedules is of public health importance, because an incomplete vaccination series may yield suboptimal disease protection. However, data on adherence of adults to multi-dose vaccines are limited. We sought to estimate adherence to multi-dose hepatitis vaccination schedules among adults in the United Kingdom (UK).

METHODS

This retrospective cohort study was conducted using anonymized electronic health record (EHR) data from the Clinical Practice Research Datalink (CPRD). Individuals aged 19 years and older at their first identified dose of hepatitis vaccine (2009-2016) were included if they had continuous EHR data for 12 months before the first identified hepatitis A dose or for 6 months before the first identified hepatitis B or combination hepatitis A/B dose. We estimated dose and series completion for each vaccine and adherence to recommended vaccination schedules, as well as adherence within additional prespecified time periods after the first vaccine dose, with sensitivity analyses restricted to adults who had available data for up to 24 months after the first dose. Median time to series completion was estimated using Kaplan-Meier methods.

RESULTS

Mean (SD) age at initiation was 42 (16) years for hepatitis A (n = 374,881), 40 (16) years for hepatitis B (n = 71,634), and 38 (15) years for hepatitis A/B (n = 10,335). Women comprised 52 to 55% of each vaccine cohort. Overall, 42,294 adults (11%) completed the two-dose hepatitis A vaccine series within the recommended 12 months; and 15,564 (22%) and 1076 (10%) completed the three-dose hepatitis B and hepatitis A/B series, respectively, within the recommended 6 months. These percentages rose to only 23, 35, and 33%, respectively, when the follow-up periods were extended to 36 months for hepatitis A and to 30 months for hepatitis B and A/B vaccines. Median times to series completion within recommended schedules were not reached in any cohort. Sensitivity analyses supported the primary findings for the full cohorts.

CONCLUSIONS

Adherence and series completion rates for hepatitis A and B vaccines in the UK are low. Identifying, understanding, and addressing barriers to series completion for multi-dose vaccines for adults in real-world settings are needed.

Cost-effective way to reduce stimulant-abuse among gay/bisexual men and transgender women: a randomized clinical trial with a cost comparison

OBJECTIVES

A randomized controlled study was conducted with 422 homeless, stimulant-using gay/bisexual (G/B) men and 29 transgender women (n = 451) to assess two community-based interventions to reduce substance abuse and improve health: (a) a nurse case-managed program combined with contingency management (NCM + CM) versus (b) standard education plus contingency management (SE + CM).

STUDY DESIGN

Hypotheses tested included: a) completion of hepatitis A/B vaccination series; b) reduction in stimulant use; and c) reduction in number of sexual partners.

METHODS

A deconstructive cost analysis approach was utilized to capture direct costs associated with the delivery of both interventions. Based on an analysis of activity logs and staff interviews, specific activities and the time required to complete each were analyzed as follows: a) NCM + CM only; b) SE + CM only; c) time to administer/record vaccines; and d) time to receive and record CM visits. Cost comparison of the interventions included only staffing costs and direct cash expenditures.

RESULTS

The study outcomes showed significant over time reductions in all measures of drug use and multiple sex partners, compared to baseline, although no significant between-group differences were detected. Cost analysis favored the simpler SE + CM intervention over the more labor-intensive NCM + CM approach. Because of the high levels of staffing required for the NCM relative to SE, costs associated with it were significantly higher.

CONCLUSIONS

Findings suggest that while both intervention strategies were equally effective in achieving desired health outcomes, the brief SE + CM appeared less expensive to deliver.

Drug Use and Multiple Sex Partners Among Homeless Ex-Offenders: Secondary Findings From an Experimental Study

BACKGROUND

Transitioning into society after release from incarceration presents real challenges for male offenders; in California, up to 60% return to prison within 3 years after release. The risk for ongoing drug use and having sex with multiple partners is a significant challenge for ex-offenders preparing to enter the community.

OBJECTIVES

The aims are to describe drug use and sexual behavior (sex with multiple partners) prior to incarceration and 6 and 12 months after study enrollment using data obtained as part of a randomized controlled trial.

METHODS

This is a planned secondary analysis of data obtained as part of a randomized controlled trial designed to study the effects of intensive peer coaching and nurse case management, intensive peer coaching, and brief nurse counseling on hepatitis A and B vaccination adherence compared to a usual care control treatment that also included brief peer coaching and brief nurse counseling. Self-report data from subjects enrolled at one residential drug treatment facility in Los Angeles were captured at three time points: baseline and 6- and 12-month follow-up.

RESULTS

Findings showed substantive and significant reductions in drug use and engaging in sex with multiple partners 6 months after enrollment into the study compared to the baseline data, but results did not differ by study condition. At 12-month follow-up, drug use and sex with multiple partners increased but remained less than at baseline levels.

DISCUSSION

Sustaining reductions in drug use and engaging in sex with multiple partners remains a challenge after incarceration.

A randomized clinical trial of tailored interventions for health promotion and recidivism reduction among homeless parolees: outcomes and cost analysis

OBJECTIVES

This study conducted a randomized controlled trial with 600 recently released homeless men exiting California jails and prisons.

METHODS

The purpose of this study was to primarily ascertain how different levels of intensity in peer coaching and nurse-partnered intervention programs may impact reentry outcomes; specifically: (a) an intensive peer coach and nurse case managed (PC-NCM) program; (b) an intermediate peer coaching (PC) program with brief nurse counseling; and (c) the usual care (UC) program involving limited peer coaching and brief nurse counseling. Secondary outcomes evaluated the operational cost of each program.

RESULTS

When compared to baseline, all three groups made progress on key health-related outcomes during the 12-month intervention period; further, 84.5 % of all participants eligible for hepatitis A/B vaccination completed their vaccine series. The results of the detailed operational cost analysis suggest the least costly approach (i.e., UC), which accounted for only 2.11 % of the total project expenditure, was as effective in achieving comparable outcomes for this parolee population as the PC-NCM and PC approaches, which accounted for 53.98 % and 43.91 %, respectively, of the project budget.

CONCLUSIONS

In this study, all three intervention strategies were found to be comparable in achieving a high rate of vaccine completion, which over time will likely produce tremendous savings to the public health system.

Impact of an intervention for recently released homeless offenders on self-reported re-arrest at 6 and 12 months

A randomized controlled trial was conducted with 600 paroled men, homeless prior to incarceration, to assess varying levels of peer-coach and nurse-partnered interventions on re-arrest at 6 and 12 months. Findings revealed that positive predictors of re-arrest at 12 months included having received social support from drug users and non-drug users, as well as having used marijuana at least once a week prior to their most recent incarceration. In terms of protective factors, those who participated in a substance abuse program contract within a residential drug treatment program or spent 90 days or greater in a residential drug treatment program were less likely to have been re-arrested within 12 months.

Nursing case management, peer coaching, and hepatitis a and B vaccine completion among homeless men recently released on parole: randomized clinical trial

BACKGROUND

Although hepatitis A virus (HAV) and hepatitis B virus (HBV) infections are vaccine-preventable diseases, few homeless parolees coming out of prisons and jails have received the hepatitis A and B vaccination series.

OBJECTIVES

The study focused on completion of the HAV and HBV vaccine series among homeless men on parole. The efficacy of three levels of peer coaching (PC) and nurse-delivered interventions was compared at 12-month follow-up: (a) intensive peer coaching and nurse case management (PC-NCM); (b) intensive PC intervention condition, with minimal nurse involvement; and (c) usual care (UC) intervention condition, which included minimal PC and nurse involvement. Furthermore, we assessed predictors of vaccine completion among this targeted sample.

METHODS

A randomized control trial was conducted with 600 recently paroled men to assess the impact of the three intervention conditions (PC-NCM vs. PC vs. UC) on reducing drug use and recidivism; of these, 345 seronegative, vaccine-eligible subjects were included in this analysis of completion of the Twinrix HAV/HBV vaccine. Logistic regression was added to assess predictors of completion of the HAV/HBV vaccine series and chi-square analysis to compare completion rates across the three levels of intervention.

RESULTS

Vaccine completion rate for the intervention conditions were 75.4% (PC-NCM), 71.8% (PC), and 71.9% (UC; p = .78). Predictors of vaccine noncompletion included being Asian and Pacific Islander, experiencing high levels of hostility, positive social support, reporting a history of injection drug use, being released early from California prisons, and being admitted for psychiatric illness. Predictors of vaccine series completion included reporting having six or more friends, recent cocaine use, and staying in drug treatment for at least 90 days.

DISCUSSION

Findings allow greater understanding of factors affecting vaccination completion in order to design more effective programs among the high-risk population of men recently released from prison and on parole.

Correlates of risky alcohol and methamphetamine use among currently homeless male parolees

Homeless men on parole are a hard-to-reach population with significant community reintegration challenges. This cross-sectional study describes sociodemographic, cognitive, psychosocial, and drug-related correlates of alcohol and methamphetamine use in 157 homeless male parolees (age range 18-60) enrolled in a substance abuse treatment center in Los Angeles, California. Logistic regression results revealed that being African American and older were negatively related to methamphetamine use, whereas being older and more hostile were related to riskier alcohol abuse. Findings from this study provide a greater understanding of correlates of methamphetamine and alcohol--two of the most detrimental forms of substances abused among currently homeless parolees.

Correlates of self-reported incarceration among homeless gay and bisexual stimulant-using young adults

Gay and bisexual (G/B) homeless adults face multiple challenges in life which may place them at high risk for incarceration. Yet, little is known about this understudied population in terms of risk for incarceration. Baseline data collected from a longitudinal study between October 2009 and March 2012 in Hollywood, California, explored correlates of self-reported incarceration among G/B homeless stimulant-using adults (N = 353). Findings revealed older age, less education, having children, as well as a history of injection drug use and being born in the United States were positively associated with incarceration. Moreover, having poor social support and having received hepatitis information were also correlated with a history of incarceration. Our findings help us gain a greater awareness of homeless G/B adults who may be at greater risk for incarceration, which may be used by health care providers to design targeted interventions for this underserved population.

Supercritical fluid extraction provides an enhancement to the immune response for orally-delivered hepatitis B surface antigen

The hepatitis B virus continues to be a major pathogen worldwide despite the availability of an effective parenteral vaccine for over 20 years. Orally-delivered subunit vaccines produced in maize may help to alleviate the disease burden by providing a low-cost, heat-stable alternative to the parenteral vaccine. Oral subunit vaccination has been an elusive goal due to the large amounts of antigen required to induce an immunologic response when administered through the digestive tract. Here we show that high levels of HBsAg were obtained in maize grain, the grain was formed into edible wafers, and wafers were fed to mice at a concentration of approximately 300 μg/g. When these wafers were made with supercritical fluid extraction (SFE)-treated maize material, robust IgG and IgA responses in sera were observed that were comparable to the injected commercial vaccine (Recombivax(®)). In addition, all mice administered SFE wafers showed high secretory IgA titers in fecal material whereas Recombivax(®) treated mice showed no detectable titer. Increased salivary IgA titers were also detected in SFE-fed mice but not in Recombivax(®) treated mice. Wafers made from hexane-treated or full fat maize material induced immunologic responses, but fecal titers were attenuated relative to those produced by SFE-treated wafers. These responses demonstrate the feasibility of using a two-dose oral vaccine booster in the absence of an adjuvant to induce immunologic responses in both sera and at mucosal surfaces, and highlight the potential limitations of using an exclusively parenteral dosing regime.