Papers by John Tanko Bawa
Vaccine, Mar 1, 2022
Background: Cervical cancer is responsible for around one-quarter of all cancer deaths among Ghan... more Background: Cervical cancer is responsible for around one-quarter of all cancer deaths among Ghanaian women. Between 2013 and 2015, Ghana conducted a pilot of HPV vaccination among 10-14-year-old girls in four regions; however, the country has yet to introduce the vaccine nationally. This study projected the cost-effectiveness and budget impact of adding HPV vaccination into Ghana's national immunization program. Methods: We used a proportional outcomes model (UNIVAC, version 1.4) to evaluate the costeffectiveness of introduction with bivalent (Cervarix TM) and quadrivalent (Gardasil Ò) vaccines from government and societal perspectives. Vaccine introduction was modeled to start in 2022 and continue over ten birth cohorts using a combined delivery strategy of school (80%) and community outreach (20%). We modeled vaccination in a single age cohort of 9-year-old girls vs. a multi-age cohort of 9-year-old girls (routine) and 10-14-year-old girls (one-time campaign) compared to no vaccination. Health outcomes included cervical cancer cases, hospitalizations, deaths, and disability-adjusted life years (DALYs). We applied a discount rate of 3% to costs and outcomes. All monetary units are reported in USD 2018. Results: National HPV vaccination in Ghana was projected to be cost-effective compared to no vaccination in all scenarios evaluated. The most cost-effective and dominant strategy was vaccination among 9-year-old girls, plus a one-time campaign among 10-14-year-old with the bivalent vaccine
Vaccine, 2022
Highlights • An effective and affordable injectable rotavirus vaccine may be attractive to LMICs.... more Highlights • An effective and affordable injectable rotavirus vaccine may be attractive to LMICs.• Co-administering oral and injectable vaccines is acceptable to many stakeholders.• Oral vaccine with a birth dose is favored over a higher cost, standalone injectable.• Providing rotavirus vaccine in a DTP combination is the most preferred option.
PLOS ONE, Jan 11, 2021
Background The RTS,S/ASO1 E malaria vaccine is being piloted in three countries-Ghana, Kenya, and... more Background The RTS,S/ASO1 E malaria vaccine is being piloted in three countries-Ghana, Kenya, and Malawi-as part of a coordinated evaluation led by the World Health Organization, with support from global partners. This study estimates the costs of continuing malaria vaccination upon completion of the pilot evaluation to inform decision-making and planning around potential further use of the vaccine in pilot areas. Methods We used an activity-based costing approach to estimate the incremental costs of continuing to deliver four doses of RTS,S/ASO1 E through the existing Expanded Program on Immunization platform, from each government's perspective. The RTS,S/ASO1 E pilot introduction plans were reviewed and adapted to identify activities for costing. Key informant interviews with representatives from Ministries of Health (MOH) were conducted to inform the activities, resource requirements, and assumptions that, in turn, inform the analysis. Both financial and economic costs per dose, cost of delivery per dose, and cost per fully vaccinated child (FVC) are estimated and reported in 2017 USD units.
Carolina Digital Repository (University of North Carolina at Chapel Hill), Oct 27, 2017
Background: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria... more Background: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. Methods: This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. Results: Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and Lambaréné, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum
Health Economics Review, 2021
Background Limited financial, human and material health resources coupled with increasing demand ... more Background Limited financial, human and material health resources coupled with increasing demand for new-born care services require efficiency in health systems to maximize the available sources for improved health outcomes. Making Every Baby Count Initiative (MEBCI) implemented by local and international partners in 2013 in Ghana aimed at attaining neonatal mortality of 21 per 1000 livebirths by 2018 in four administrative regions in Ghana. MEBCI interventions benefited 4027 health providers, out of which 3453 (86%) were clinical healthcare staff. Objective Determine the per capita cost of the MEBCI interventions towards enhancing new-born care best practices through capacity trainings for frontline clinical and non-clinical staff. Methods Parameters for determining per capita cost of the new-born care interventions were estimated using expenditure on trainings, supervisions, monitoring and evaluation, advocacy, administrative/services and medical logistics. Data collection started...
Background Malaria remains a public health challenge in Sub-Saharan Africa with the region contri... more Background Malaria remains a public health challenge in Sub-Saharan Africa with the region contributing to more than 90% of global cases in 2020. In Ghana, the malaria vaccine was piloted to assess the feasibility, safety, and its impact in the context of routine use alongside the existing recommended malaria control measures. To obtain context-specific evidence that could inform future strategies of introducing new vaccines, a standardized post-introduction evaluation (PIE) of the successes and challenges of the malaria vaccine implementation programme (MVIP) was conducted. Methods From September to December 2021, the WHO Post-Introduction Evaluation (PIE) tool was used to conduct a mix method evaluation of the pilot introduction of the malaria vaccine in Ghana. To ensure representativeness, study sites and participants from the national level, 18 vaccinating districts, and 54 facilities from the seven pilot regions were purposively selected. Data was collected using a questionnair...
Malaria journal, Oct 27, 2017
Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmissio... more Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site ...
New England Journal of Medicine, 2011
Background An ongoing phase 3 study of the efficacy, safety, and immunogenicity of candidate mala... more Background An ongoing phase 3 study of the efficacy, safety, and immunogenicity of candidate malaria vaccine RTS,S/AS01 is being conducted in seven African countries. Methods From March 2009 through January 2011, we enrolled 15,460 children in two age categories-6 to 12 weeks of age and 5 to 17 months of age-for vaccination with either RTS,S/AS01 or a non-malaria comparator vaccine. The primary end point of the analysis was vaccine efficacy against clinical malaria during the 12 months after vaccination in the first 6000 children 5 to 17 months of age at enrollment who received all three doses of vaccine according to protocol. After 250 children had an episode of severe malaria, we evaluated vaccine efficacy against severe malaria in both age categories. Results In the 14 months after the first dose of vaccine, the incidence of first episodes of clinical malaria in the first 6000 children in the older age category was 0.32 episodes per person-year in the RTS,S/AS01 group and 0.55 episodes per person-year in the control group, for an efficacy of 50.4% (95% confidence interval [CI], 45.8 to 54.6) in the intention-to-treat population and 55.8% (97.5% CI, 50.6 to 60.4) in the per-protocol population. Vaccine efficacy against severe malaria was 45.1% (95% CI, 23.8 to 60.5) in the intention-to-treat population and 47.3% (95% CI, 22.4 to 64.2) in the per-protocol population. Vaccine efficacy against severe malaria in the combined age categories was 34.8% (95% CI, 16.2 to 49.2) in the per-protocol population during an average follow-up of 11 months. Serious adverse events occurred with a similar frequency in the two study groups. Among children in the older age category, the rate of generalized convulsive seizures after RTS,S/AS01 vaccination was 1.04 per 1000 doses (95% CI, 0.62 to 1.64). Conclusions The RTS,S/AS01 vaccine provided protection against both clinical and severe malaria in African children. (Funded by GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative; RTS,S ClinicalTrials.gov number, NCT00866619.
New England Journal of Medicine, 2012
Background The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe ... more Background The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe malaria in children 5 to 17 months of age by approximately 50% in an ongoing phase 3 trial. We studied infants 6 to 12 weeks of age recruited for the same trial. Methods We administered RTS,S/AS01 or a comparator vaccine to 6537 infants who were 6 to 12 weeks of age at the time of the first vaccination in conjunction with Expanded Program on Immunization (EPI) vaccines in a three-dose monthly schedule. Vaccine efficacy against the first or only episode of clinical malaria during the 12 months after vaccination, a coprimary end point, was analyzed with the use of Cox regression. Vaccine efficacy against all malaria episodes, vaccine efficacy against severe malaria, safety, and immunogenicity were also assessed. Results The incidence of the first or only episode of clinical malaria in the intention-to-treat population during the 14 months after the first dose of vaccine was 0.31 per personyear in the RTS,S/AS01 group and 0.40 per person-year in the control group, for a vaccine efficacy of 30.1% (95% confidence interval [CI], 23.6 to 36.1). Vaccine efficacy in the per-protocol population was 31.3% (97.5% CI, 23.6 to 38.3). Vaccine efficacy against severe malaria was 26.0% (95% CI, −7.4 to 48.6) in the intention-totreat population and 36.6% (95% CI, 4.6 to 57.7) in the per-protocol population. Serious adverse events occurred with a similar frequency in the two study groups. One month after administration of the third dose of RTS,S/AS01, 99.7% of children were positive for anti-circumsporozoite antibodies, with a geometric mean titer of 209 EU per milliliter (95% CI, 197 to 222). Conclusions The RTS,S/AS01 vaccine coadministered with EPI vaccines provided modest protection against both clinical and severe malaria in young infants. (Funded by Glaxo SmithKline Biologicals and the PATH Malaria Vaccine Initiative; RTS,S ClinicalTrials.gov number, NCT00866619.
PLOS ONE
Background Live oral rotavirus vaccines (LORVs) have significantly reduced rotavirus hospitalizat... more Background Live oral rotavirus vaccines (LORVs) have significantly reduced rotavirus hospitalizations and deaths worldwide. However, LORVs are less effective in low- and middle-income countries (LMICs). Next-generation rotavirus vaccines (NGRVs) may be more effective but require administration by injection or a neonatal oral dose, adding operational complexity. Healthcare providers (HPs) were interviewed to assess rotavirus vaccine preferences and identify delivery issues as part of an NGRV value proposition. Objective Determine HP vaccine preferences about delivering LORVs compared to injectable (iNGRV) and neonatal oral (oNGRV) NGRVs. Methods 64 HPs from Ghana, Kenya, Malawi, Peru, and Senegal were interviewed following a mixed-method guide centered on three vaccine comparisons: LORV vs. iNGRV; LORV vs. oNGRV; oNGRV vs. iNGRV. HPs reviewed attributes for each vaccine in the comparisons, then indicated and explained their preference. Additional questions elicited views about co-adm...
Vaccine
Highlights • An effective and affordable injectable rotavirus vaccine may be attractive to LMICs.... more Highlights • An effective and affordable injectable rotavirus vaccine may be attractive to LMICs.• Co-administering oral and injectable vaccines is acceptable to many stakeholders.• Oral vaccine with a birth dose is favored over a higher cost, standalone injectable.• Providing rotavirus vaccine in a DTP combination is the most preferred option.
Vaccine
BACKGROUND Cervical cancer is responsible for around one-quarter of all cancer deaths among Ghana... more BACKGROUND Cervical cancer is responsible for around one-quarter of all cancer deaths among Ghanaian women. Between 2013 and 2015, Ghana conducted a pilot of HPV vaccination among 10-14-year-old girls in four regions; however, the country has yet to introduce the vaccine nationally. This study projected the cost-effectiveness and budget impact of adding HPV vaccination into Ghana's national immunization program. METHODS We used a proportional outcomes model (UNIVAC, version 1.4) to evaluate the cost-effectiveness of introduction with bivalent (Cervarix™) and quadrivalent (Gardasil®) vaccines from government and societal perspectives. Vaccine introduction was modeled to start in 2022 and continue over ten birth cohorts using a combined delivery strategy of school (80%) and community outreach (20%). We modeled vaccination in a single age cohort of 9-year-old girls vs. a multi-age cohort of 9-year-old girls (routine) and 10-14-year-old girls (one-time campaign) compared to no vaccination. Health outcomes included cervical cancer cases, hospitalizations, deaths, and disability-adjusted life years (DALYs). We applied a discount rate of 3% to costs and outcomes. All monetary units are reported in USD 2018. RESULTS National HPV vaccination in Ghana was projected to be cost-effective compared to no vaccination in all scenarios evaluated. The most cost-effective and dominant strategy was vaccination among 9-year-old girls, plus a one-time campaign among 10-14-year-old with the bivalent vaccine ($158/DALY averted from the government perspective; 95% credible range: $19-$280/DALY averted). Projected average annual costs of the vaccine program ranged from $11.2 to $15.4 M, depending on strategy. This represents 11-15% of the estimated total immunization costs for 2022 ($100,857,875 based on Ghana's comprehensive Multi-Year Plan for Immunization, 2020-2024). DISCUSSION Our model suggests that introducing HPV vaccination would be cost-effective in Ghana under any strategy when willingness-to-pay is at least 40% GDP per capita ($881). Inclusion of a one-time catch-up campaign is shown to create greater value for money than routine immunization alone but would incur greater program costs.
PLOS ONE
Background The RTS,S/ASO1E malaria vaccine is being piloted in three countries—Ghana, Kenya, and ... more Background The RTS,S/ASO1E malaria vaccine is being piloted in three countries—Ghana, Kenya, and Malawi—as part of a coordinated evaluation led by the World Health Organization, with support from global partners. This study estimates the costs of continuing malaria vaccination upon completion of the pilot evaluation to inform decision-making and planning around potential further use of the vaccine in pilot areas. Methods We used an activity-based costing approach to estimate the incremental costs of continuing to deliver four doses of RTS,S/ASO1E through the existing Expanded Program on Immunization platform, from each government’s perspective. The RTS,S/ASO1E pilot introduction plans were reviewed and adapted to identify activities for costing. Key informant interviews with representatives from Ministries of Health (MOH) were conducted to inform the activities, resource requirements, and assumptions that, in turn, inform the analysis. Both financial and economic costs per dose, cos...
New England Journal of Medicine, 2012
The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe malaria in ... more The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe malaria in children 5 to 17 months of age by approximately 50% in an ongoing phase 3 trial. We studied infants 6 to 12 weeks of age recruited for the same trial.
New England Journal of Medicine, 2012
The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe malaria in ... more The candidate malaria vaccine RTS,S/AS01 reduced episodes of both clinical and severe malaria in children 5 to 17 months of age by approximately 50% in an ongoing phase 3 trial. We studied infants 6 to 12 weeks of age recruited for the same trial.
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Papers by John Tanko Bawa