Existing Vaccination Programs Research Articles

Provider and community perceptions of integrated COVID-19 and routine childhood immunisation programmes in Nigeria: a qualitative exploratory study

BackgroundIn Nigeria, COVID-19 vaccines were delivered through outreach activities, as well as integrated within routine immunisation. However, evaluations of integrated approaches for novel vaccines are scarce. We aimed to understand the perceived benefits and challenges of integrating the COVID-19 vaccine within routine immunisation in Nigeria, and identify ways to strengthen this approach.MethodsWe conducted 30 semi-structured interviews with community members and healthcare workers in primary healthcare facilities (PHCs) in Jigawa (n = 16) and Oyo (n = 14) states, Nigeria from 08 August to 13 September 2022. Participants were selected purposively from PHCs. We obtained information on participants’ perception about routine immunisation, and perceived benefits and challenges associated with integrated COVID-19 vaccine delivery. Healthcare worker and community interviews were analysed separately following a thematic analysis approach.ResultsWe identified four themes that describe the community and healthcare workers’ responses, perceived impact, and the health system adaptions to the challenges associated with the integrated vaccine delivery approach. Community members expressed concern that children might be given COVID-19 vaccines instead of routine immunisations, while others appreciated the integrated approach due to their trust in the efficacy of COVID-19 vaccines, government, and healthcare providers. Healthcare providers perceived the integrated approach as improving vaccination coverage and awareness but noted additional problems of increased workload, vaccine scarcity, and prolonged clinic visits. Insufficient resources were subsisting barriers to effective integration in both states, but the provider’s gender was also a challenge in Jigawa state. Additionally, the use of incentives to generate demand had ambiguous effects in Jigawa state.ConclusionTaking an integrated approach to deliver COVID-19 vaccines was acceptable by healthcare providers but community members expressed concerns. Given existing vaccination programmes have persistent challenges, it is pertinent to address these barriers to enhance effectiveness of an integrated approach.

Estimating averted illnesses from influenza vaccination for children and pregnant women – El Salvador, Panama, and Peru, 2011–2018

BackgroundEstimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011–2018 among two influenza vaccine target populations: children aged 6–23 months and pregnant women. MethodsWe derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries’ vaccine coverage was achieved using four different vaccine deployment strategies. ResultsAmong children aged 6–23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March—June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women). DiscussionInfluenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign.

Seroprevalence of hepatitis B virus surface antigen (HBsAg) in Egypt (2000–2022): a systematic review with meta-analysis

BackgroundHepatitis B infection seriously threatens global public health, especially in developing nations. Despite several investigations on HBV incidence, the national pooled prevalence remains unknown, particularly in populations at-risk at whom interventions should be primarily aimed.MethodsA comprehensive literature search of the following databases: Medline [PubMed], Scopus, Google Scholar, and Web of Science was conducted following the PRISMA guidelines. I-squared and Cochran's Q were used to measure the heterogeneity between the studies. Publications that matched the following were included: Primary studies published in Egypt from 2000 to 2022 reported HBV prevalence based on HBsAg. We excluded any studies that were not performed on Egyptians or that were performed on patients suspected of acute viral hepatitis or studies focusing on occult hepatitis or vaccination evaluation studies, or national surveys.ResultsThe systematic review included 68 eligible studies reporting a total of 82 incidences of HBV infection based on hepatitis B surface antigen with a total sample size of 862,037. The pooled national prevalence among studies was estimated to be 3.67% [95% CI; 3: 4.39]. Children under 20 with a history of HBV vaccination during infancy had the lowest prevalence of 0.69%. The pooled prevalence of HBV infection among pregnant women, blood donors, and healthcare workers was 2.95%, 1.8%, and 1.1%, respectively. While patients with hemolytic anemia and hemodialysis patients, patients with malignancies, HCC patients, and chronic liver disease patients had the highest prevalences at 6.34%, 25.5%, 18.6%, and 34%, respectively. Studies reporting HBV prevalence in urban settings compared to rural settings revealed a similar HBV prevalence of 2.43% and 2.15%, respectively. Studies comparing HBV prevalence in males and females revealed a higher prevalence among males (3.75%) than females (2.2%).ConclusionIn Egypt, hepatitis B infection is a significant public health issue. The blocking of mother-to-infant hepatitis B transmission, the scaling up of the scope of the existing vaccination program, and implementing new strategies, including screen-and-treat, may reduce the prevalence of the disease.

Influenza hospitalisations in Spain between the last influenza and COVID-19 pandemic (2009-2019).

Knowing the burden of severe disease caused by influenza is essential for disease risk communication, to understand the true impact of vaccination programmes and to guide public health and disease control measures. We estimated the number of influenza-attributable hospitalisations in Spain during the 2010-2011 to 2019-2020 seasons - based on the hospitalisations due to severe acute respiratory infection (SARI) in Spain using the hospital discharge database and virological influenza information from the Spanish Influenza Sentinel Surveillance System (SISSS). The weekly numbers of influenza-attributable hospitalisations were calculated by multiplying the weekly SARI hospitalisations by the weekly influenza virus positivity, obtained from the SISSS in each season, stratified by age group and sex. The influenza-related hospitalisation burden is age-specific and varies significantly by influenza season. People aged 65 and over yielded the highest average influenza-attributable hospitalisation rates per season (615.6 per 100,000), followed by children aged under 5 (251.2 per 100,000). These results provide an essential contribution to influenza control and to improving existing vaccination programmes, as well as to the optimisation and planning of health resources and policies.

Guillain-Barre Syndrome After COVID-19 Vaccination: A Secondary Analysis of Domestic Safety Data by the Japanese Government

Purpose The purpose of this study was to figure out the risk of Guillain-Barre syndrome (GBS) after coronavirus disease 2019 (COVID-19) vaccination, which has been reported as a rare adverse reaction. Methods Elucidating the characteristics, we performed a secondary analysis of the cases from February 2020through January 2022, based on the publicly available spontaneous adverse reaction reports in Japan. Results We identified 115 cases, and all were after messenger RNA (mRNA) vaccination. Of all the cases, 69 (60.0%) were female and 44 (38.2%) were older than 65 years old. Severe GBS was reported by 38 males (median age 61.5 years) and 51 females (median age 55 years). The median interval from vaccination to the onset of symptoms was eight days for males and four days for females. Sequelae were reported in 18 patients (7 males, median age 81 years; 11 females, median age 51 years), 11 of whom were older than 65 years old. The estimated incidence was about 0.0001% (0.000058% for the Pfizer vaccine and about 0.000046% for the Moderna vaccine, respectively). Conclusions Spontaneous reports would have various biases, the incidence of GBS after mRNA vaccination was as low as in other existing vaccination programs, and it is important not to interpret that risk expansively.

Molecular Evolution of Porcine Reproductive and Respiratory Syndrome Virus Field Strains from Two Swine Production Systems in the Midwestern United States from 2001 to 2020.

ABSTRACTPorcine reproductive and respiratory syndrome virus (PRRSV) poses an extensive economic threat to the United States swine industry. The high degree of PRRSV genetic and antigenic variability challenges existing vaccination programs. We evaluated the ORF5 sequence of 1,931 PRRSV-2 strains detected from >300 farms managed by two pork production systems in the midwestern United States from 2001 to 2020 to assess the genetic diversity and molecular characteristics of heterologous PRRSV-2 strains. Phylogenetic analysis was performed on ORF5 sequences and classified using the global PRRSV classification system. N-glycosylation and the global and local selection pressure in the putative GP5 encoded by ORF5 were estimated. The PRRSV-2 sequences were classified into lineage 5 (L5; n = 438[22.7%]) or lineage 1 (L1; n = 1,493[77.3%]). The L1 strains belonged to one of three subclades: L1A (n = 1,225[63.4%]), L1B (n = 69[3.6%]), and L1C/D (n = 199[10.3%]). 10 N-glycosylation sites were predicted, and positions N44 and N51 were detected in most GP5 sequences (n = 1,801[93.3%]). Clade-specific N-glycosylation sites were observed: 57th in L1A, 33rd in L1B, 30th and 34th in L1C/D, and 30th and 33rd in L5. We identified nine and 19 sites in GP5 under significant positive selection in L5 and L1, respectively. The 13th, 151st, and 200th positive selection sites were exclusive to L5. Heterogeneity of N-glycosylation and positive selection sites may contribute to varying the evolutionary processes of PRRSV-2 strains circulating in these swine production systems. L1A and L5 strains denoted excellence in adaptation to the current swine population by their extensive positive selection sites with higher site-specific selection pressure.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) is known for its high genetic and antigenic variability. In this study, we evaluated the ORF5 sequences of PRRSV-2 strains circulating in two swine production systems in the midwestern United States from 2001 to 2020. All the field strains were classified into four major groups based on genetic relatedness, where one group is closely related to the Ingelvac PRRS MLV strain. Here, we systematically compared differences in the ORF5 polymorphisms, N-glycosylation sites, and local and global evolutionary dynamics between different groups. Sites 44 and 51 were common for N-glycosylation in most amino acid sequences (n = 1,801, 93.3%). We identified that the L5 sequences had more positive selection pressure compared to the L1 strains. Our findings will provide valuable insights into the evolutionary mechanisms of PRRSV-2 and these molecular changes may lead to suboptimal effectiveness of Ingelvac PRRS MLV vaccine.

Descriptive study of cattle and dog rabies cases in the Sheki-Zagatala region of Azerbaijan (2015–2016): Knowledge, attitudes, and practices of people towards rabies

Every year, rabies causes great damage to human health and the economy of countries around the world. This neurotropic and zoonotic viral disease is endemic to Azerbaijan. This study describes cattle and dog rabies cases identified between 2015 and 2016. In addition, a questionnaire was administered to 100 respondents comprised of case owners, and non-case animal owners, to assess knowledge, attitudes, and practices within this population. The study demonstrates a general lack of knowledge of rabies in the participating communities. The majority of respondents were familiar with rabies and understood that animal bites are a source of transmission. However, many respondents did not know that rabies is preventable and admitted not knowing additional routes of transmission. In addition, there was less perceived risk with contact with animal saliva. Despite free vaccinations in Azerbaijan, only 27 out of 45 dogs in this study were vaccinated. Although educational programming and preventive vaccination of dogs has been implemented, and significant progress has been made in the sphere of epidemiological surveillance and prevention, rabies cases remain problematic in the Sheki-Zagatala region. Regular educational programs for communities, strengthening of the existing vaccination programs, and a comprehensive epidemiological case-control study to identify the disease risk factors could help reduce the burden of rabies in Azerbaijan.

A Decade of Fighting Invasive Meningococcal Disease: A Narrative Review of Clinical and Real-World Experience with the MenACWY-CRM Conjugate Vaccine.

The quadrivalent A, C, W and Y meningococcal vaccine conjugated to nontoxic mutant of diphtheria toxin (MenACWY-CRM) has been licensed since 2010 for the prevention of invasive meningococcal disease (IMD), an uncommon but life-threatening condition. Here, we summarize the experience accrued with MenACWY-CRM during the first decade since its licensure, by providing an overview of clinical trials investigating the safety, immunogenicity and co-administration of MenACWY-CRM with other vaccines as well as presenting real-world evidence regarding the impact of MenACWY-CRM vaccination on carriage and IMD incidence. MenACWY-CRM has demonstrated an acceptable clinical safety profile across a wide range of age groups; no safety concerns have been reported in special populations, such as immunocompromised infants and toddlers, or pregnant women. MenACWY-CRM has also been proven to be immunogenic in various age groups and geographic settings, and a booster dose has been shown to elicit strong anamnestic responses in all studied populations, irrespective of the vaccine used for priming. With no clinically relevant vaccine interactions reported, MenACWY-CRM is being conveniently integrated into existing vaccination programs for various age and risk groups; this possibility of co-administration helps improving vaccine coverage and streamlining the healthcare process of fighting preventable infectious diseases. Vaccination of adolescents and adults has been proven to reduce nasopharyngeal carriage for serogroups C, W and Y, which is an important element in reducing transmission. Real-world evidence indicates that MenACWY-CRM can reduce IMD incidence even in high-exposure groups. When combined with vaccines against serogroup B meningococci, MenACWY-CRM can offer protection against five of the most common serogroups responsible for IMD, which is an important advantage in the continuously evolving landscape of meningococcal serogroup epidemiology.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40121-021-00519-2.

Financial impact of sheeppox and goatpox and estimated profitability of vaccination for subsistence farmers in selected northern states of Nigeria

Sheeppox and goatpox (SGP) are important transboundary diseases, endemic in Nigeria, causing severe clinical manifestations, impacting production, and resulting in economic losses. Vaccination is an effective control measure against SGP in endemic countries but is not currently implemented in Nigeria. This study aimed to estimate SGP financial impact and assess economic viability of SGP vaccination at the herd and regional level under different scenarios in Northern Nigeria. Integrated stochastic production and economic herd models were developed for transhumance and sedentary herds. Models were run for two disease scenarios (severely and slightly affected) and with and without vaccination, with data parameterisation from literature estimates, field survey and authors’ experience. Herd-level net financial impact of the disease and its vaccination was assessed using gross margin (GM) and partial budget analyses. These were then used to assess regional financial impact of disease and profitability of a 3-year vaccination programme using a cost-benefit analysis. The regional-analysis was performed under 0 %, 50 % and 100 % government subsidy scenarios; as a standalone programme or in combination with other existing vaccination programmes; and for risk-based and non-risk-based intervention.Median SGP losses per reproductive female were £27 (90 % CI: £31-£22), and £5 (90 % CI: £7-£3), in sedentary, and £30 (90 % CI: £41-21), and £7 (90 % CI: £10-£3), in transhumance herds, for severely and slightly affected scenarios respectively. Selling animals at a reduced price, selling fewer young animals, and reduced value of affected animals remaining in the herd were the greatest contributors to farmer’s SGP costs. SGP-affected herds realised a GM reduction of up to 121 % in sedentary and 138 % in transhumance. Median estimated regional SGP cost exceeded £24 million. Herd-level median benefits of vaccination per reproductive female were £23.76 (90 % CI: £19.28-£28.61), and £4.01 (90 % CI: £2.36-£6.31), in sedentary, and £26.85 (90 % CI: £17.99-£37.02) and £7.45 (90 % CI: £3.47-£15.14) in transhumance herds, in severely and slightly affected scenarios, respectively. Median benefit: cost ratio (BCR) for severely affected herds at 50% subsidies was 6.62 (90% CI: 5.30-8.90) for sedentary, and 5.14 (90% CI: 3.31-13.81) for transhumance herds. The regional SGP vaccination standalone programme BCR: 7–27, regional SGP vaccination with existing vaccination programme BCR: 7–228 and vaccinating high-risk areas BCR: 19–439 were found to be economically viable for all subsidy levels explored. Vaccinating low-risk areas only realised benefits with 100 % of government subsidies.This study further increases understanding of SGP’s impact within Northern Nigeria and demonstrates vaccination is an economically viable control strategy at the herd-level and also regionally, depending on the strategy and government subsidy levels considered.

The road to cervical cancer elimination in Malaysia: Evaluation of the impact and cost-effectiveness of human papillomavirus screening with self-collection and digital registry support.

The WHO has launched a global strategy to eliminate cervical cancer through the scale‐up of human papillomavirus (HPV) vaccination, cervical screening, and cervical cancer treatment. Malaysia has achieved high‐coverage HPV vaccination since 2010, but coverage of the existing cytology‐based program remains low. Pilot studies found HPV self‐sampling was acceptable and effective, with high follow‐up rates when a digital registry was used, and recently the Malaysian Government announced plans for a national HPV‐based screening program. We therefore evaluated the impact of primary HPV screening with self‐collection in Malaysia in the context of Malaysia's existing vaccination program. We used the “Policy1‐Cervix” modeling platform to assess health outcomes, cost‐effectiveness, resource use and cervical cancer elimination timing (the year when cervical cancer rates reach four cases per 100 000 women) of implementing primary HPV testing with self‐collection, assuming 70% routine‐screening coverage could be achieved. Based on available data, we assumed that compliance with follow‐up was 90% when a digital registry was used, but that compliance with follow‐up would be 50‐75% without the use of a digital registry. We found that the current vaccination program would prevent 27 000 to 32 200 cervical cancer cases and 11 700 to 14 000 deaths by 2070. HPV testing with a digital registry was cost‐effective (CER = $US 6953‐7549 < $US 11 373[<1×GDP per capita]) and could prevent an additional 15 900 to 17 800 cases and 9700 to 10 600 deaths by 2070, expediting national elimination by 11 to 20 years, to 2055 to 2059. If HPV screening were implemented without a digital registry, there would be 1800 to 4900 fewer deaths averted by 2070 and the program would be less cost‐effective. These results underline the importance of HPV testing as a key elimination pillar in Malaysia.

Parental Care on Under Five Child Health Outcomes in Zimbabwe

This study examines the effect of parental care on child health outcomes (stunting, wasting and underweight) in Zimbabwe. The study uses data from the Zimbabwe Demographic Health Survey (ZDHS) (1994-2015) by employing the Ordinary Least Method (OLS) regression approach. The results indicate that breastfeeding and vaccination on each count has a significant negative effect on under-five child health outcomes (stunting and wasting). On the contrary, child-size shows a significant positive effect on wasting and underweight among under-five children in Zimbabwe. Area of residence indicates an under five-child in an urban center is less likely to be wasting than its contemporary in a rural area. The individual effects of mothers’ education, wealth index, child’s sex and marital status show insignificant effects under-five child health outcomes. The policy implication is that health professionals should intensify education on early child suckling and succeeding dietary mix to obviate poor health outcomes. This study also implores the Ministry of Health and Child Care in Zimbabwe to review existing vaccination programmes by extending to households with poor child health outcomes found in inaccessible areas. As a contribution, this study provides a platform for deliberations on family care and child health care in African societies.

Influenza, Shingles and Pneumococcal Vaccine Uptake, Offer and Refusal in Adult Populations at High-Risk for COVID-19: A UK Population-Based Cohort Study

Background: As COVID-19 vaccination programs are being rolled out globally, we studied the ethnic, deprivation, household size and comorbidity ‘patterning’ of existing vaccination programs in populations at high-risk for COVID-19, to inform risk-stratified vaccination strategies and mitigate health inequalities. Methods: A population-level cohort study of UK adults aged 65 years or older, using a large primary care database. We used multivariable logistic regression to assess uptake of influenza, pneumococcal and shingles vaccination across ethnic groups, deprivation quintile, household size, and comorbidities, computing odds ratios (OR) adjusted for age, sex, demographics, body mass index and smoking. Offers and refusals of each vaccination type were analysed in those not receiving them. Findings: The cohort comprised 2,054,463 patients from 1,318 general practices. 1,452,014 (70.7%) patients received influenza vaccine, 1,391,228 (67.7%) received pneumococcal vaccine, and 690,783 (53.4%) received shingles vaccine. Compared to Whites, influenza vaccination uptake was lower in Pakistani (adjusted odds ratio (OR) 0.82; 99% confidence interval: 0.74-0.90), Black Caribbean (OR 0.46; 0.43-0.48), Black African (OR 0.63; 0.58-0.68), Chinese (OR 0.70; 0.64-0.76) and ‘Other ethnic group’ (OR 0.65; 0.63-0.69). The Black Caribbean group had higher vaccination refusal than the White group for influenza vaccination (OR 1.17; 1.05-1.30). Vaccination uptake was lower among the more deprived and those living in household sizes above 3 or more persons, with some significant interactions between ethnicity and comorbidities. Uptake of all three vaccines was higher in those with asthma, COPD, type 2 diabetes, hypertension and learning disability, whilst lower in those with dementia. Interpretation: Whilst uptake and refusal of influenza, shingles and pneumococcal vaccination are patterned by ethnicity, deprivation, household size and comorbidities, vaccination offer is mostly patterned by comorbidities. This information can inform national policies to ensure equitable implementation of COVID-19 vaccination programs to avoid exacerbating health inequalities.Funding Statement: This project was funded by the Medical Research Council (Grant Ref: MR/V027778/1).Declaration of Interests: PST reports previous consultation with AstraZeneca and Duke-NUS outside the submitted work. KK is a Member of the Scientific Advisory Group for Emergencies (SAGE), Member of Independent SAGE, Director of the University of Leicester Centre for Black Minority Health and Trustee of the south Asian Health Foundation. JHC is a member of several SAGE committees and chair of the risk stratification subgroup of the NERVTAG. She is unpaid director of QResearch and founder and former medical director of ClinRisk Ltd (outside the submitted work). MP, AKC, HDM, DS, TAR, FZ, BRS, SJG, CC, CG have no interests to declare.

Managing BVDV at the herd level part 1

Bovine viral diarrhoea virus (BVDV) is a costly disease and its eradication is the focus of the English voluntary scheme, BVDFree. The process of identifying a farm as negative or not negative is broken down into four stages using ADAM: assess disease risk; define herd status; action plan for BVD control; monitor progress. This process is based on the long-established protocols defined by Cattle Health Certification Standards. The first two stages are discussed in this article with the others following in part 2 of this series. The risk assessment for current infection should focus on incoming animals to the herd, boundary fences and existing vaccination programmes. Suitable testing can then follow with a choice of newborn screening or youngstock cohort surveillance, with optional bulk milk analysis in dairy herds. Farms that show initial evidence of endemic BVDV infection can undertake further testing to discover the source.

A systematic review of BCG vaccination policies among high-risk groups in low TB-burden countries: implications for vaccination strategy in Canadian indigenous communities

BackgroundBacille Calmette-Guérin (BCG) vaccination against tuberculosis (TB) is widespread in high-TB-burden countries, however, BCG vaccination policies in low-burden countries vary. Considering the uncertainties surrounding BCG efficacy and the lower likelihood of TB exposure in low-incidence countries, most have discontinued mass vaccination, choosing instead a targeted vaccination strategy among high-risk groups. Given the increased risk of TB infection in Canadian Indigenous communities compared to the general Canadian population, these communities are a pertinent example of high-incidence groups in an otherwise low-burden country, warranting particular consideration regarding BCG vaccination strategy. This systematic review aims to synthesise and critically appraise the literature on BCG vaccination strategies in high-risk groups in low-incidence settings to provide policy considerations relevant to the Canadian Indigenous context.Methods: A literature search of the Medline and Embase databases was conducted, returning studies pertaining to BCG vaccine efficacy, TB incidence under specific vaccination policies, BCG-associated adverse events, and vaccination policy guidelines in low-burden countries. Study screening was tracked using the Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia), and data pertaining to the above points of interest were extracted.ResultsThe final review included 49 studies, spanning 15 countries. Although almost all of these countries had implemented a form of mass or routine vaccination previously, 11 have since moved to targeted vaccination of selected risk groups, in most cases due to the low risk of infection among the general population and thus the high number of vaccinations needed to prevent one case in the context of low-incidence settings. Regarding identifying risk groups for targeted screening, community-based (rather than individual risk-factor-based) vaccination has been found to be beneficial in high-incidence communities within low-incidence countries, suggesting this approach may be beneficial in the Canadian Indigenous setting.ConclusionsCommunity-based vaccination of high-incidence communities may be beneficial in the Canadian Indigenous context, however, where BCG vaccination is implemented, delivery strategies and potential barriers to achieving adequate coverage in this setting should be considered. Where an existing vaccination program is discontinued, it is crucial that an effective TB surveillance system is in place, and that case-finding, screening, and diagnostic efforts are strengthened in order to ensure adequate TB control. This is particularly relevant in Canadian Indigenous and other remote or under-served communities, where barriers to surveillance, screening, and diagnosis persist.

An updated systematic review and meta-analysis of the prevalence of hepatitis B virus in Ethiopia

BackgroundHepatitis B virus is one of the major public health concerns globally. It is highly infectious and can be transmitted from person to person through vertically or horizontally via contaminated body fluids. Despite the provision of an effective vaccine, it remains a major problem worldwide, particularly among the developing countries.MethodsOnline electronic databases including PubMed, Google Scholar, Science Direct, African Index Medicus, African Journals Online, and WHO Afro Library were searched and published articles from 2010 to June 8, 2019, were considered. Both authors independently screened articles and extracted the data. Funnel-Plots and Egger’s test statistics were used to determine the presence of small-study effects and publication bias. The pooled prevalence of HBV was analyzed using the random-effects model. The possible sources of heterogeneity was analyzed through subgroup analysis, sensitivity analysis, and meta-regression.ResultsThe overall pooled prevalence of HBV was 6% and among subgroups, pregnant women, healthcare workers, and HIV positive patients accounted for 5% for each group. Relatively low prevalence (4%) was obtained among blood donors. The Egger’s test statistics (p = 0.747) indicated the absence of publication bias. In addition, from the sensitivity analysis, there was no influence on the overall effect estimate while removing a single study at a time. The level of heterogeneity was reduced among pregnant women, HIV positive and studies with unknown sampling techniques. After conducting meta-regression, province, study group, screening method, and quality of papers were identified as sources of heterogeneity.ConclusionsThe overall pooled prevalence of HBV in Ethiopia was high. Strengthening and scaling up of the scope of the existing vaccination program and implementing novel approaches including screen-and-treat could be implemented to reduce the burden of the disease. Generally, the study can provide current prevalence estimate of HBV that could vital for intervention to tackle the disease.

Assessment of novel vaccination regimens using viral vectored liver stage malaria vaccines encoding ME-TRAP

Heterologous prime-boost vaccination with viral vectors simian adenovirus 63 (ChAd63) and Modified Vaccinia Ankara (MVA) induces potent T cell and antibody responses in humans. The 8-week regimen demonstrates significant efficacy against malaria when expressing the pre-erythrocytic malaria antigen Thrombospondin-Related Adhesion Protein fused to a multiple epitope string (ME-TRAP). We tested these vaccines in 7 new 4- and 8- week interval schedules to evaluate safety and immunogenicity of multiple ChAd63 ME-TRAP priming vaccinations (denoted A), multiple MVA ME-TRAP boosts (denoted M) and alternating vectors. All regimens exhibited acceptable reactogenicity and CD8+ T cell immunogenicity was enhanced with a 4-week interval (AM) and with incorporation of additional ChAd63 ME-TRAP vaccination at 4- or 8-weeks (AAM or A_A_M). Induction of TRAP antibodies was comparable between schedules. T cell immunity against the ChAd63 hexon did not affect T cell responses to the vaccine insert, however pre-vaccination ChAd63-specific T cells correlated with reduced TRAP antibodies. Vaccine-induced antibodies against MVA did not affect TRAP antibody induction, and correlated positively with ME-TRAP-specific T cells. This study identifies potentially more effective immunisation regimens to assess in Phase IIa trials and demonstrates a degree of flexibility with the timing of vectored vaccine administration, aiding incorporation into existing vaccination programmes.

Reaching every child with rotavirus vaccine: Report from the 10th African rotavirus symposium held in Bamako, Mali.

The Center for Vaccine Development - Mali (CVD - Mali), the World Health Organization's regional office in Africa (WHO/AFRO), and the CVD at the University of Maryland School of Medicine hosted the 10th African Rotavirus Symposium in Bamako, Mali on 1-2 June 2016. The symposium is coordinated by WHO/AFRO, the Regional Rotavirus Reference Laboratories, and the African Rotavirus Network (ARN), with support from the Bill & Melinda Gates Foundation. The event brings together leading rotavirus researchers, scientists, and policy-makers from across Africa and the world. Over 150 participants, from 31 countries, including 27 in Africa, joined forces to address the theme "Reaching Every Child in Africa with Rotavirus Vaccines." This symposium, the first in francophone Africa, occurred at an unprecedented time when 33 African countries had introduced rotavirus vaccines into their national immunization programs. The symposium concluded with a Call to Action to introduce rotavirus vaccines in the 21 remaining African countries, to increase access in countries with existing vaccination programs, and to continue surveillance and research on rotavirus and other diarrheal diseases.

The impact of current infection levels on the cost-benefit of vaccination

When considering a new vaccine programme or modifying an existing one, economic cost-benefit analysis, underpinned by predictive epidemiological modelling, is a key component. This analysis is intimately linked to the willingness to pay for additional QALYs (quality-adjusted life-years) gained; currently in England and Wales a health programme is economically viable if the cost per QALY gained is less than £ 20,000, and models are often used to assess if a vaccine programme is likely to fall below this threshold cost. Before a programme begins, infection levels are generally high and therefore vaccination may be expected to have substantial effects and therefore will often be economically viable. However, once a programme is established, and infection rates are lower, it might be expected that a re-evaluation of the programme (using current incidence information) will show it to be less cost-effective. This is the scenario we examine here with analytical tools and simple ODE models. Surprisingly we show that in most cases the benefits from maintaining an existing vaccination programme are at least equal to those of starting the programme initially, and in the majority of scenarios the differences between the two are minimal. In practical terms, this is an extremely helpful finding, allowing us to assert that the action of immunising individuals does not de-value the vaccination programme.

Improving specificity of Bordetella pertussis detection using a four target real-time PCR

The incidence of whooping cough, a contagious respiratory disease caused by Bordetella pertussis, is on the rise despite existing vaccination programmes. Similar, though usually milder, respiratory symptoms may be caused by other members of the Bordetella genus: B. parapertussis, B. holmesii, and B. bronchiseptica. Pertussis diagnosis is mostly done using PCR, but the use of multiple targets is necessary in order to differentiate the different Bordetella spp. with sufficient sensitivity and specificity. In this study we evaluate a multiplex PCR assay for the differentiation of B. pertussis from other Bordetella spp., using the targets IS481, IS1001, IS1002, and recA. Moreover, we retrospectively explore the epidemiology of Bordetella spp. infections in Belgium, using the aforementioned assay over a three-year period, from 2013 until 2015.

Human Papillomavirus Vaccination of Boys and Extended Catch-up Vaccination: Effects on the Resilience of Programs.

Decreasing human papillomavirus (HPV) vaccine prices makes scaling up of vaccination programs attractive for countries that initially targeted 1 or a few birth cohorts of girls and/or achieved low coverage. This article aims to compare the impact of alternative HPV vaccination strategies, using data from Sweden, a high-income country that has experienced vaccine price changes. Using an HPV transmission model, we compared the existing vaccination program to alternatives, accounting for a 1-time catch-up vaccination of 22-26-year-old women, with or without routine vaccination of school-age boys, and for a 1-time catch-up vaccination of males aged 13-26 years. We also assessed the resilience of vaccination alternatives to coverage reduction. On the basis of an HPV16/18 prevalence of 12% before the HPV vaccine era, extended catch-up vaccination for females and males yielded relative reductions in the HPV prevalence of 49.4% and 55.6%, respectively, during the first 10 years after the start of each vaccination strategy, whereas the existing program yielded a relative reduction of 38.6% during the same period. The increased prevalence reduction due to catch-up vaccination continued for about 30 years. As compared to female-only routine and extended catch-up vaccination, routine vaccination of males with or without catch-up was, respectively, 12.6-fold and 7.2-fold more resilient to coverage reduction. Vaccination strategies based on catch-up vaccination of females and males are effective for accelerating HPV prevalence reduction. Inclusion of routine male vaccination improves the resilience of vaccination programs.