Multicenter study on the immunogenicity and safety of two recombinant vaccines against hepatitis B

Impaired anti-HBV vaccine response in non-cirrhotic chronic HCV is not overcome by double dose regimen: randomized control trial

INTRODUCTION AND OBJECTIVES

Some studies suggest chronic HCV infection diminishes responses to the anti-HBV vaccine. We evaluated the efficacy of double versus standard dose HBV vaccination among HCV patients without cirrhosis.

PATIENTS AND METHODS

141 adults with untreated chronic HCV were randomized to HBV vaccination with double dose (40μg) or standard dose (20μg) at 0, 1 and 6 months; 70 healthy HCV-negative patients given standard dose served as controls. Vaccine response was defined by anti-HBs ≥10 mIU/mL.

RESULTS

128 patients (60 double, 68 standard doses) completed the study. Patients were of median age 52 years, 61% female, 60% fibrosis <2 of 4, and 76% genotype 1 with median 6-log 10 IU/mL HCV RNA. Overall seroprotection rate was 76.7% (95% CI: 65-87) in the 40μg versus 73.5% (95% CI: 63-84) in the 20μg dose HCV-positive groups (p =0.68) and 91.2% (95%CI:84-99) in HCV-negative controls (p =0.011 and 0.003, respectively). In multivariate logistic regression, vaccine dose (double vs. standard dose) was not associated with vaccine response (OR=0.63, p =0.33). Of 32 HCV-infected patients who were non-responders to 3- doses, 25 received the fourth dose of vaccine. The fourth dose seroconversion rate for the 40μg and 20μg groups were 45.5% and 21.4%, respectively.

CONCLUSIONS

In HCV-infected patients without cirrhosis, impaired responses to HBV vaccination cannot be overcome by the use of double dose HBV vaccination, but adding a fourth dose of vaccine for non-responders may be an effective strategy. Other adjuvant measures are needed to enhance seroconversion rates in these patients.

TRIAL REGISTER

U 1111-1264-2343 (www.ensaiosclinicos.gov.br).

[A plea for introduction of hepatitis B vaccination at birth in Côte d'Ivoire]

The Côte d'Ivoire National Immunization Technical Advisory Group 2015 work plan included elaboration of an opinion on inclusion of hepatitis B vaccination at birth in the Expanded Program on Immunization (EPI) in Côte d'Ivoire. A task force was set up to conduct this assessment according to a systematized method. The task force analysed scientific articles on the burden of hepatitis B in Côte d'Ivoire, the burden of mother-child transmission, the impact of hepatitis B vaccination at birth in countries which have adopted this strategy, the efficacy and safety of hepatitis B vaccine in newborns, the cost-effectiveness of hepatitis B vaccination at birth, and the best strategy to introduce hepatitis B vaccination at birth in the EPI. The National Immunization Technical Advisory Group of Côte d'Ivoire finally recommended introduction of a dose of hepatitis B vaccine at birth in the context of the Expanded Program on Immunization with maintenance of three doses of pentavalent vaccine (DPT-HepB-Hib) at 6, 10, and 14 weeks of age.

Low Immunogenicity of Recombinant Hepatitis B Vaccine Derived from Hansenula polymorpha in Adults Aged Over 40 Years

The Brazilian recombinant hepatitis B vaccine (VrHB-IB) is based on the expression of the recombinant antigen in Hansenula polymorpha yeast cells. Currently, data on the immunogenicity of this vaccine in older adults are nonexistent. This study aimed to evaluate the immunogenicity of VrHB-IB in adults over 40 years of age. From May to October 2011, 235 rural settlers between 2 and 93 years of age from the State of Goias in Brazil were eligible for vaccination. Of these, 180 accepted the first dose of the vaccine and 106 (58.9%) completed the vaccination schedule. Multivariate analysis revealed that individuals ≥ 40 years of age responded significantly less well to vaccination than younger adults. Also, a greater proportion of male nonresponders was observed (versus women; P = 0.02). These results point to the need for better evaluation of the immunogenicity of VrHB-IB in older adults.

Factors influencing immunologic response to hepatitis B vaccine in adults

Hepatitis B was still a worldwide health problem. This study aimed to conducted a systematic review and meta-analysis to assess a more precise estimation of factors that influence the response to hepatitis B vaccine in adults. Our included studies examined seroprotection rates close to the end of vaccination schedules in healthy adult populations. This meta-analysis including 21053 adults in 37 articles showed that a significantly decreased response to hepatitis B vaccine appeared in adults (age ≥ 40) (RR:1.86, 95% CI:1.55–2.23), male adults (RR:1.40, 95% CI:1.22–1.61), BMI ≥ 25 adults (RR:1.56, 95% CI:1.12–2.17), smoker (RR:1.53, 95% CI:1.21–1.93), and adults with concomitant disease (RR:1.39, 95% CI:1.04–1.86). Meanwhile, we further found a decreased response to hepatitis B vaccine appeared in adults (age ≥ 30) (RR:1.77, 95% CI:1.48–2.10), and adults (age ≥ 60) (RR:1.30, 95% CI:1.01–1.68). However, there were no difference in response to hepatitis B vaccine both in alcoholic (RR:0.90, 95% CI:0.64–1.26) and 0-1-12 vs. 0-1-6 vaccination schedule (RR:1.39, 95% CI:0.41–4.67). Pooling of these studies recommended the sooner the better for adult hepatitis B vaccine strategy. More vaccine doses, supplemental/additional strengthening immunity should be emphasized on the susceptible population of increasing aged, male, BMI ≥ 25, smoking and concomitant disease. The conventional 0-1-6 vaccination schedule could be still worth to be recommended.

Historical review of clinical vaccine studies at Oswaldo Cruz Institute and Oswaldo Cruz Foundation--technological development issues

This paper presents, from the perspective of technological development and production, the results of an investigation examining 61 clinical studies with vaccines conducted in Brazil between 1938-2013, with the participation of the Oswaldo Cruz Institute (IOC) and the Oswaldo Cruz Foundation (Fiocruz). These studies have been identified and reviewed according to criteria, such as the kind of vaccine (viral, bacterial, parasitic), their rationale, design and methodological strategies. The results indicate that IOC and Fiocruz have accumulated along this time significant knowledge and experience for the performance of studies in all clinical phases and are prepared for the development of new vaccines products and processes. We recommend national policy strategies to overcome existing regulatory and financing constraints.

Childhood vaccination associated adverse events by sex: a literature review

BACKGROUND

Most approved medicines, including vaccines can be associated with adverse events. A vaccine adverse event is defined as any untoward medical occurrence which follows vaccination, but which does not necessarily have a causal relationship with the administration of the vaccine.

METHODS

The objective of this structured literature review is to analyse the adverse events reported with vaccinations usually done during childhood and adolescence: human papilloma virus vaccine, hepatitis B vaccine and measles-mumps-rubella vaccine. We evaluated the vaccine literature on children and adolescents by sex. We searched the Cochrane Database, Medline (Pubmed) and Embase using predefined terms.

RESULTS

Of the 417 publications retrieved from searches in the 3 databases, 89 papers (21%) were identified as potentially relevant to the review. On further scrutiny 41 of these satisfied the criteria for inclusion in the analysis. Serious adverse events related to vaccinations were rare. We found some possible sex related vaccine adverse events. Few trials however reported adverse events by age and sex and very few analyses evaluated the observed differences.

CONCLUSIONS

Despite earlier calls for sex-specific analyses of clinical studies, we found that vaccine trials were rarely reported and published by sex. Prospectively collated vaccine safety data in children and adolescents should be analysed by age and sex, so that clinical trial results can form an evidence base for vaccine practice recommendations.

Seroprotection after recombinant hepatitis B vaccination among newborn infants: a review

INTRODUCTION

Hepatitis B vaccination starting at birth provides a safety net for infants exposed to hepatitis B virus (HBV) during delivery or in early life. Hepatitis B vaccine is recommended in the United States for infants prior to birthing facility discharge, and within the first 12h of life for infants born to hepatitis B surface antigen (HBsAg)-positive mothers. We performed a literature review and summarized the response to recombinant hepatitis B vaccine among infants.

METHODS

Studies published between 1987 and 2011 assessing seroprotection from recombinant hepatitis B vaccine starting within the first 30 days of life were eligible. Seroprotection was defined using an antibody to hepatitis B surface antigen (anti-HBs) threshold of 10mIU/mL at series completion. Infant seroprotection was compared in trial arms varying by maternal hepatitis B antigen status (e antigen [HBeAg], HBsAg), hepatitis B immune globulin (HBIG) administration, birth weight, vaccine dosage, schedule, and age at first dose.

RESULTS

Forty-three studies were included. The median seroprotection proportion overall was 98% (range 52%, 100%). The final median seroprotection proportions did not vary appreciably by maternal HBsAg status, HBIG administration, or schedule. Higher compared to lower dosage resulted in earlier increases in anti-HBs but not in final seroprotection proportions. Infants with birth weights <2000g compared to ≥2000g had lower median seroprotection proportions (93% and 98%, respectively). Median seroprotection proportions were also lower when infants with birth weights <2000g were vaccinated at 0-3 days of age compared to 1 month of age or older (68% versus 95%, respectively).

CONCLUSION

High levels of protection from recombinant hepatitis B vaccine are achieved in term infants vaccinated at birth, effectively preventing transmission of HBV and resultant morbidity and mortality. Implications, if any, for long-term protection are unknown for differences in responses among infants vaccinated at birth compared to ages older than 1 month.

Estratégias de campo em ensaios clínicos com novas vacinas produzidas no Brasil

OBJETIVO: Relatar as estratégias de campo utilizadas em dois ensaios clínicos com vacinas desenvolvidas pelo Instituto Butantan, em 2004 e 2006. MÉTODOS: Estudo do tipo relato de experiência, em que se descreve o planejamento e a operacionalização dos ensaios clínicos, que avaliaram a imunogenicidade e a segurança da vacina BCG combinada com a vacina da hepatite B (VrHB-IB) e da tetravalente bacteriana modificada pela extração do lipopolissacarídeo (LPS) do componente pertussis (DTPm/Hib). RESULTADOS: As principais estratégias de campo utilizadas foram: a) Parceria entre os pesquisadores e os gestores da Secretaria Municipal de Saúde e b) Realização dos procedimentos da pesquisa nos domicílios ou nos Centros de Saúde frequentados pelos participantes. No primeiro estudo, foram vacinados 552 recém-nascidos na maternidade com a BCG/VrHB-IB (combinadas ou separadas) e nos domicílios, com as duas doses subsequentes de VrHB-IB. O segundo estudo incluiu 241 lactentes em Centros de Saúde da rede municipal, vacinados com tetravalente bacteriana (com componente pertussis total ou modificado). Em ambos os estudos, amostras de sangue foram colhidas nas residências. Não houve relatos de eventos adversos. A adesão foi de 90,2% para o primeiro estudo e 93,8%, para o segundo. As vacinas foram administradas nas datas preconizadas pelo Programa Nacional de Imunizações e as coletas de sangue, de acordo com o cronograma dos estudos. CONCLUSÕES: As estratégias utilizadas facilitaram o recrutamento das crianças e garantiram cumprir o protocolo da pesquisa com alta adesão, sem interferir no vínculo da família com o Serviço de Saúde, no calendário vacinal ou no seguimento pediátrico dos participantes.

Avaliação do sistema brasileiro de vigilância de eventos adversos pós-vacinação

OBJETIVOS: Descrever e avaliar o Sistema brasileiro de vigilância passiva de eventos adversos pós-vacinação (SPVEAPV). MÉTODOS: A descrição e avaliação do SPVEAPV fundamentaram-se nas notificações de eventos adversos pós-vacina Tetravalente ou DTwP/Hib - vacina adsorvida difteria, tétano, pertussis e Haemophilus influenzae b (conjugada) - (EAPV-T), durante o período de 2002 a 2005. Empregou-se a metodologia proposta pelo Centers for Disease Control and Prevention. RESULTADOS: O SPVEAPV apresenta abrangência nacional, tem por objetivos identificar e padronizar condutas frente a casos de eventos adversos pós-vacinação (EAPV) e identificar lotes reatogênicos. A vigilância é útil, simples e flexível, sua sensibilidade é baixa, superestima os eventos mais graves, mas descreve de forma consistente os EAPV-T, identificando a convulsão, a febre e o episódio hipotônico-hiporresponsivo como os mais frequentes, apontando a maior proporção de EAPV na primeira dose (49,7%) e nas primeiras seis horas após a vacinação (72,8%); é útil ao subsidiar decisões e investigações complementares; 46,1% das notificações são feitas até 10 dias após a vacinação; sua completude varia de 70% a 90%, conforme o item. CONCLUSÕES: O SPVEAPV mostra-se útil no monitoramento da segurança da vacina DTwP/Hib, sendo, porém, recomendável a incorporação de novas metodologias como a de municípios e/ou hospitais sentinelas e a de sistemas informatizados de registros de imunização com a finalidade de elevar sua sensibilidade.

Imunogenicidade da vacina brasileira contra hepatite B em adultos

OBJETIVO: Avaliar a imunogenicidade e segurança da vacina contra hepatite B, após o aumento na concentração do antígeno HBsAg para 25 μg, em comparação à vacina de referência. MÉTODOS: Ensaio com alocação aleatória e mascaramento simples, comparando a VrHB-IB (Instituto Butantan) com a vacina de referência (Engerix B®, Glaxo Smith Kline). Os voluntários, entre 31 e 40 anos de idade (n=419), foram alocados aleatoriamente ao grupo experimental (n=216) ou ao grupo controle (n=203), e receberam três doses de vacina. A primeira dose foi administrada no momento do recrutamento, a segunda e terceira 30 e 180 dias depois respectivamente, entre 2004 e 2005. Amostras de sangue foram colhidas para análise sorológica antes da randomização, e após a segunda e terceira doses. Foi realizada a vigilância ativa de eventos adversos durante os cinco primeiros dias após a vacinação. As diferenças foram avaliadas pelos testes do qui-quadrado e exato de Fisher, com nível de significância de 5%. RESULTADOS: Não se observaram eventos adversos graves. A soroporteção foi confirmada em 98,6% (213/216) dos voluntários do grupo experimental, em comparação a 95,6% (194/203) do grupo controle. Os títulos geométricos médios foram de 12.557 e 11.673, respectivamente. CONCLUSÕES: A vacina brasileira foi considerada equivalente à vacina de referência e seu uso recomendado para adultos.

Model for product development of vaccines against neglected tropical diseases: a vaccine against human hookworm

This article provides an overview of the advances in product development and technology transfer of the vaccine against human hookworm, with particular emphasis on the lessons learned and the challenges of developing a vaccine in the nonprofit sector. The comprehensive approach to vaccine development established by the Human Hookworm Vaccine Initiative (HHVI) identifies key operational and technical aspects that are essential for a successful partnership with a developing country vaccine manufacturer. This article also highlights the importance of a global access roadmap to guide the vaccine development program. The advancement of new products for the control of neglected tropical diseases portends great challenges for global access, including aspects related to vaccine design, product development and manufacture, vaccine introduction and distribution, financing, knowledge dissemination and intellectual property management. With only three vaccines for neglected tropical diseases in clinical trials - hookworm, leishmaniasis and schistosomiasis - we are at the nascent stages of developing vaccines for neglected populations. Product development public-private partnerships, such as the HHVI, continue to show great promise on this front and will eventually provide significant control tools for achieving millennium development goals related to poverty reduction, as well as child and maternal health.

Hepatitis B immunisation in persons not previously exposed to hepatitis B or with unknown exposure status

BACKGROUND

The benefits and harms of hepatitis B vaccination in persons not previously exposed to hepatitis B infection or with unknown exposure status have not been established.

OBJECTIVES

To assess the benefits and harms of hepatitis B vaccination in people not previously exposed to hepatitis B infection or with unknown exposure status.

SEARCH STRATEGY

Trials were identified from The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS,Science Citation Index Expanded (last search, March 2007). Additionally, we contacted experts and vaccine manufacturers, and read through reference lists for eligible trials.

SELECTION CRITERIA

Randomised clinical trials comparing hepatitis B vaccine versus placebo, no intervention, or another vaccine in persons not previously exposed to hepatitis B (HBsAg negative) or with unknown exposure status.

DATA COLLECTION AND ANALYSIS

The primary outcome was hepatitis B infection (detecting HBsAg, HBeAg, HBV DNA, or anti-HBc). Secondary outcomes were lack of sero-protection, antibody titre, clinical complications, adverse events, lack of compliance, and cost-effectiveness. Dichotomous outcomes were reported as relative risk (RR) with 95% confidence interval (CI), using intention-to-treat analysis assuming an unfavourable event for missing data. Sensitivity analyses based on methodological quality (risk of bias), available data analysis, intention-to-treat analysis assuming a favourable event for missing data, best-case scenario, and worst-case scenario were conducted.

MAIN RESULTS

Twelve trials were eligible. All had high risk of bias and reporting was inconsistent. Hepatitis B vaccine did not show a clear effect on the risk of developing HBsAg (RR 0.96, 95% CI 0.89 to 1.03, 4 trials, 1230 participants) and anti-HBc (RR 0.81, 95% CI 0.61 to 1.07; 4 trials, 1230 participants, random-effects) when data were analysed using intention-to-treat analysis assuming an unfavourable event for missing data. Analysis based on data of available participants showed reduced risk of developing HBsAg (RR 0.12, 95% CI 0.03 to 0.44, 4 trials, 576 participants) and anti-HBc (RR 0.36, 95% CI 0.17 to 0.76, 4 trials, 576 participants, random-effects). Intention-to-treat analysis assuming favourable outcome for missing data showed similar reduction in risk. Hepatitis B vaccination had an unclear effect on the risk of lacking protective antibody levels (RR 0.57, 95% CI 0.26 to 1.27, 3 trials, 1210 participants, random-effects). Development of adverse events was sparsely reported.

AUTHORS' CONCLUSIONS

In people not previously exposed to hepatitis B, vaccination has unclear effect on the risk of developing infection, as compared to no vaccination. The risk of lacking protective antibody levels as well as serious and non-serious adverse events appear comparable among recipients and non-recipients of hepatitis B vaccine.

Immunogenicity and safety of combined intradermal recombinant Hepatitis B with BCG vaccines at birth

This randomized, prospective, non-inferiority study aimed to quantify anti-HBs titers induced by recombinant Hepatitis B vaccine from healthy infants vaccinated with combined Hepatitis B and Bacillus Calmette-Guérin (BCG) vaccines (HbsAg 10 microg plus BCG suspension 0.1mg) and compare them to titers obtained with separated vaccines. Infants were immunized at birth either with combined intradermal (ID) BCG and Hepatitis B or ID BCG alone and intramuscular (IM) Hepatitis B. Both groups received IM Hepatitis B at 1 and 6 months of age. After the third dose anti-HBs titers > or =10 IU/mL were observed in 99% of vaccinees and > or =1000 IU/mL in 71%. There were no adverse events in both groups. Combination of HbsAg with BCG as first dose did not modify the profile of the humoral immune response for Hepatitis B indicating safety and immunogenicity of this vaccine in newborn.

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Protection against hepatitis B by the Butang® recombinant vaccine in newborn children in South Brazil

The prevention of hepatitis B by vaccination is one of the most efficient tools to avoid the transmission of the virus. This study evaluated the immunogenicity of the national vaccine Butang in children born in Campo Mourão City, state of Paraná, Brazil, aged 7 to 12 months, by determining the anti-HBsAg antibodies levels after completion of the National Immunization Program Protocol for hepatitis B. All 70 children evaluated by the MEIA method (immune-enzymatic micro particles) showed seroconversion to the Butang vaccine. Nine children (12.9%) presented a low response, with anti-HBs titers between 11 and 100 mUI/ml; 39 children (55.7%) showed a good response to the vaccine, with titers between 101 and 1000 mUI/ml; and 22 children (31.4%) showed antibodies titers higher than 1000 mUI/ml. The mean titer of the anti-HBs antibody titers was 1408.1 +/- 2870.26 mUI/ml (15.7 to 19560.0 m UI/ml). The levels of antibodies produced by the prematurely-born children were not statistically different from those found in the newborns. Fifty-five children were also evaluated through the ELFA method (ELISA with a final detection in fluorescence), which presented similar results. The results obtained in our study corroborated the effectiveness of the national vaccine Butang in newborn children of Campo Mourão City, Paraná, even if they were premature.

Seroepidemiology of hepatitis B virus infection and high rate of response to hepatitis B virus Butang®vaccine in adolescents from low income families in Central Brazil

In order to evaluate the seroepidemiology and response to Butang vaccine in adolescents from low income families in Central Brazil, blood samples of 664 adolescents were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) markers, and multiple logistical regression analysis was carried out to determine variables associated with hepatitis B virus (HBV) infection markers. further, three 20 microg Butang vaccine doses were offered to all susceptible individuals (n = 304). Among those who accepted them (n = 182), the seroresponse was evaluated in 170 individuals by quantitative anti-HBs. an overall hbv prevalence of 5.9% was found: four adolescents were HBsAg positive, 24 were anti-HBc, anti-HBs-reactive, and 11 were anti-HBc only. The analyse of risk factors showed that age 16-19 years, place of birth outside Goiás, school B and body piercing were statistically associated with HBV infection markers (p < 0.05). All 170 adolescents responded to Butang, and a geometric mean titer (gmt) of 4344 mUI/ml was obtained. these results reinforce the importance of hepatitis b vaccine in adolescents despite of the hbv regional endemicity, and suggest that three doses of 20 microg of the Butang should guarantee protective anti-hbs levels to individuals at a critical time for hepatitis b acquiring such as latter adolescence and adulthood.