Papers by Evanson Z Sambala
Vaccines are excellent investments with far-reaching rewards beyond individual and population hea... more Vaccines are excellent investments with far-reaching rewards beyond individual and population health, but their introduction into national programs has been historically slow in Africa. We provide an overview of the introduction of new and underutilized vaccines in countries of the WHO African Region by 2017, using data from the WHO-UNICEF Joint Reporting Form. By 2017, all 47 countries had introduced vaccines containing hepatitis B (compared to 11% in 2000 and 98% in 2010) and Haemophilus influenzae type b (Hib) (compared to 4% in 2000 and 91% in 2010). The proportion of countries that had introduced other vaccines by 2017 was 83% for pneumococcal conjugate vaccine (PCV) from 7% in 2010, 72% for rota-virus vaccine from 2% in 2010, 55% for the second dose of a measles-containing vaccine (MCV2) (com-pared to 11% in 2000 and 17% in 2010), and 45% for rubella-containing vaccines (RCV) (compared to 4% in 2000 and 7% in 2010). From 2000 to 2010, there was no significant difference between countries eligible (N = 36) and those not eligible (N = 10) for Gavi support in the introduction of hepatitis B and PCV. However, Gavi eligible countries were more likely to introduce Hib and non-Gavi eligible countries were more likely to introduce MCV2 and RCV. From 2010 to 2017, the only significant differences that remained between the two groups of countries were with mumps, inactivated polio and seasonal influenza vaccines; which non-Gavi eligible countries were more likely to have introduced. There has been significant progress in the introduction of new childhood vaccines in Africa, mostly driven by Gavi support. As many countries are expected to transition out of Gavi support soon, there is need for countries in the region to identify predictable, reliable and sustainable immunization funding mechanisms. This requires commitments and actions that go beyond the purchase of vaccines.
Background: Prior to the 2009 pandemic H1N1, and the unprecedented outbreak of Highly Pathogenic ... more Background: Prior to the 2009 pandemic H1N1, and the unprecedented outbreak of Highly Pathogenic Avian Influenza (HPAI) caused by the H5N1 virus, the World Health Organization (WHO) called upon its Member States to develop preparedness plans in response to a new pandemic in humans. The WHO Member States responded to this call by developing national pandemic plans in accordance with the International Health Regulations (IHR) to strengthen the capabilities of Member States to respond to different pandemic scenarios. In this study, we aim to evaluate the quality of the preparedness plans in the WHO African region since their inception in 2005. Methods: A standard checklist with 61 binary indicators (" yes " or " no ") was used to assess the quality of the preparedness plans. The checklist was categorised across seven thematic areas of preparedness: preparation (16 indicators); coordination and partnership (5 indicators); risk communication (8 indicators); surveillance and monitoring (7 indicators); prevention and containment (10 indicators); case investigation and treatment (10 indicators) and ethical consideration (5 indicators). Four assessors independently scored the plans against the checklist.
We describe the existence and functionality of National Immunisation Technical Advisory Groups (N... more We describe the existence and functionality of National Immunisation Technical Advisory Groups (NITAGs) in Africa between 2010 and 2016, using data from the WHO-UNICEF Joint Reporting Form. The number of African countries with NITAGs increased from 15 (28%) in 2010 to 26 (48%) in 2016. Countries with a functioning NITAG increased from 5(9%) in 2010 to 16 (30%) in 2016. In 2016, 13 of the 27 (48%) lowincome African countries reported having a NITAG; seven (54%) of them functional. Thirteen of the 26 (50%) middle-income countries reported having a NITAG; nine (69%) of them functional. In 2016, six of the seven African countries (86%) in the WHO Eastern Mediterranean Region had a NITAG, with three (50%) functional. In the WHO African Region, 20 of the 47 countries (43%) had NITAGs; 13 (65%) of them functional. Substantial investments should be made to ensure that every African country has a functional NITAG.
Understanding the gaps in missed opportunities for vaccination (MOV) in sub-Saharan Africa would ... more Understanding the gaps in missed opportunities for vaccination (MOV) in sub-Saharan Africa would inform interventions for improving immunisation coverage to achieving universal childhood immunisation. We aimed to conduct a multicountry analyses to decompose the gap in MOV between poor and non-poor in SSA. We used cross-sectional data from 35 Demographic and Health Surveys in SSA conducted between 2007 and 2016. Descriptive statistics used to understand the gap in MOV between the urban poor and non-poor, and across the selected covariates. Out of the 35 countries included in this analysis, 19 countries showed pro-poor inequality, 5 showed pro-non-poor inequality and remaining 11 countries showed no statistically significant inequality. Among the countries with statistically significant pro-illiterate inequality, the risk difference ranged from 4.2% in DR Congo to 20.1% in Kenya. Important factors responsible for the inequality varied across countries. In Madagascar, the largest contributors to inequality in MOV were media access, number of under-five children, and maternal education. However, in Liberia media access narrowed inequality in MOV between poor and non-poor households. The findings indicate that in most SSA countries, children belonging to poor households are most likely to have MOV and that socioeconomic inequality in is determined not only by health system functions, but also by factors beyond the scope of health authorities and care delivery system. The findings suggest the need for addressing social determinants of health.
Missed opportunities for vaccination (MOV) is an important barrier hindering full immunisation co... more Missed opportunities for vaccination (MOV) is an important barrier hindering full immunisation coverage among eligible children. Though factors responsible for MOV are well documented in literature, little attention has been paid to the role of inequalities. The aim of this study is to examine the association between structural or compositional factors and education inequalities in MOV. Blinder-Oaxaca decomposition technique was used to explain the factors contributing to the average gap in missed opportunities for vaccination between uneducated and educated mothers in sub-Saharan Africa using DHS survey data from 35 sub Saharan African countries collected between 2007 and 2016. The sample contained 69,657 children aged 12 to 23 months. We observed a wide variation and inter-country differences in the prevalence of missed opportunity for vaccination across populations and geographical locations. Our results show that the prevalence of MOV in Zimbabwe among uneducated and educated mothers was 9% and 21% respectively while in Gabon corresponding numbers were 85% and 89% respectively. In 15 countries, MOV was significantly prevalent among children born to uneducated mothers (pro-illiterate inequality) while in 5 countries MOV was significantly prevalent among educated mothers (pro-educated inequality). Our results suggest that education-related inequalities in missed opportunities for vaccination are explained by compositional and structural characteristics; and that neighbourhood socio-economic status was the most important contributor to education-related inequalities across countries followed by either the presence of under-five children, media access or household wealth index. The results showed that differential effects such as neighbourhood socio-economic status, presence of under-five children, media access and household wealth index, primarily explained education-related inequality in MOV. Interventions to reduce gaps in education-related inequality in MOV should focus on social determinants of health.
Vaccination programmes in Africa have made extraordinary progress over the last four decades. Yet... more Vaccination programmes in Africa have made extraordinary progress over the last four decades. Yet, vaccine hesitancy threatens to erode these gains. Vaccine hesitancy is a continuum between vaccine acceptance and refusal. A growing number of people in Africa are delaying or refusing recommended vaccines for themselves or their children, even when safe and effective vaccines are available. This predisposes communities to infectious diseases, resulting in multiple disease outbreaks, ultimately consuming resources and costing lives. Vaccine hesitancy is currently receiving unprecedented global attention, however, there remains several knowledge gaps, particularly in Africa. The vast majority of research on this topic has been conducted in high income countries. Little is therefore known about the nature and causes of vaccine hesitancy in Africa, and evidence-based interventions in the region to address it are also limited. Moreover, tools to measure vaccine hesitancy are scarce, and none that exist has been validated in Africa. We discuss these knowledge gaps, and propose a research and capacity building agenda to better measure and overcome vaccine hesitancy in Africa. Ultimately, this is essential if we hope to enhance and sustain public demand for vaccination and preserve the tremendous achievements of vaccination programmes on the continent.
Global Health Action, 2017
Background: In 2006, Malawi developed a national influenza plan to mitigate, prevent and manage t... more Background: In 2006, Malawi developed a national influenza plan to mitigate, prevent and manage the burden of infection should an outbreak occur. In 2009, it translated its contingency plan to respond to the unfolding influenza pandemic. However, little is known of how Malawi translated its national influenza plan into response actions, or the success of these responses. Objective: To investigate how Malawi translated its preparedness plan and so broaden our understanding of the outcomes of the responses. Methods: We draw on data from 22 in-depth interviews with government policymakers and people working at a policy level in various non-governmental organisations, conducted to assess the level of preparedness and the challenges of translating this. Results: Through a number of public health initiatives, authorities developed communication strategies, strengthened influenza surveillance activities and updated overall goals in pandemic training and education. However, without influenza drills, exercises and simulations to test the plan, activating the pandemic plan, including coordinating and deploying generic infection control measures, was problematic. Responses during the pandemic were at times 'weak and clumsy' and failed to mirror the activities and processes highlighted in the preparedness plan. Conclusions: Participants stressed that in order to achieve a coordinated and successful response to mitigate and prevent the further transmission of pandemic influenza, good preparation was critical. The key elements which they identified as relevant for a rapid response included effective communications, robust evidence-based decision-making, strong and reliable surveillance systems and flexible public health responses. To effectively articulate a viable trajectory of pandemic responses, the potential value of simulation exercises could be given more consideration as a mean of sustaining good levels of preparedness and responses against future pandemics. These all demand a well-structured planning for and response to pandemic influenza strategy developed by a functioning scientific and policy advisory committee.
Background: In the late 1990s, in the context of renewed concerns of an influenza pandemic, count... more Background: In the late 1990s, in the context of renewed concerns of an influenza pandemic, countries such as Ghana and Malawi established plans for the deployment of vaccines and vaccination strategies. A new pandemic was declared in mid-June 2009, and by April 2011, Ghana and Malawi vaccinated 10% of the population. We examine the public health policy perspectives on vaccination as a means to prevent the spread of infection under post pandemic conditions.
Ethical problems are addressed in various ways within countries in planning for and response to p... more Ethical problems are addressed in various ways within countries in planning for and response to pandemic influenza. Here we report on a qualitative study, in which 46 policymakers in Malawi and Ghana were interviewed on how they identified and resolved ethical problems. The study results revealed that ethical problems involving conflicts of values and choices were raised in reference to the extent and role of resources (inequities) and nature of public health interventions (intrusive measures), including the extent and processes of decision making, reasoning, and justification. There is a need for an ethical framework within pandemic preparedness plans to resolve and avert these problems.
Journal of Public Health Management and …, Jan 1, 2011
Croatian medical journal, Jan 1, 2010
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Papers by Evanson Z Sambala