Proposing a New Conceptual Syndemic Framework for COVID-19 Vaccine Hesitancy: A Narrative Review

BACKGROUND

Discussions regarding syndemics have dominated research in recent years. Vaccine hesitancy has also been propelled to the forefront. In this narrative review, we aim to frame a novel syndemic framework to understand the interaction between vaccine hesitancy, COVID-19, and negative health outcomes.

METHODS

A non-systematic electronic search was conducted in PubMed and Google Scholar. Search criteria were limited to articles published between November 2019 and June 2022. Articles related to the COVID-19 syndemic and vaccine hesitancy were included.

RESULTS

Our review revealed that the adherence to COVID-19 regulations-although they were effective in preventing COVID-19 transmission, cases, and deaths-created a dynamically unstable 'vicious cycle' between undesirable health, economic, and social outcomes. The "accumulation" of complex stressors decreased individuals' cognitive flexibility and hindered them from making decisions and getting vaccinated. Furthermore, it increased individuals' risk of acquiring COVID-19, losing their employment, increasing poverty, and decreasing healthcare utilization. We illustrated how the amalgamation of sociodemographic and contextual factors associated with COVID-19 might impact people's vaccine decisions, making them more hesitant toward COVID-19 vaccination. Failing to receive vaccinations increases the chances of COVID-19 transmission, hospitalization, and other negative health outcomes.

CONCLUSIONS

Understanding the interaction between these factors is essential to provide policymakers with inspiration to set appropriate interventions for promoting COVID-19 vaccination acceptance to decrease the overall burden of pandemics.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Africa: Current Considerations and Future Projections

The burden of severe Covid-19 has been relatively low in sib-Saharan Africa compared to Europe and the Americas. However, SARS-CoV-2 sero-prevalence data has demonstrated that there has been more widespread transmission than can be deduced from reported cases. This could be attributed to under reporting due to low testing capacity or high numbers of asymptomatic SARS-CoV-2 infection in communities. Recent data indicates that prior SARS-CoV-2 exposure is protective against reinfection and that vaccination of previously SARS-CoV-2 infected individuals induces robust cross-reactive antibody responses. Considering these data, calls for a need for a re-think of the COVID-19 vaccination strategy in sub-Saharan African settings with high SARSCoV-2 population exposure but limited available vaccine doses. A potential recommendation would be to prioritize rapid and widespread vaccination of the first dose, while waiting for more vaccines to become available.

The long road of pandemic vaccine development to rollout: A systematic review on the lessons learnt from the 2009 H1N1 influenza pandemic

Background

The 2009 Influenza A(H1N1) pandemic prompted one of the largest public health responses in history. The continuous emergence of new and deadly pathogens has highlighted the need to reflect upon past experiences to improve pandemic preparedness. The aim of this study was to examine the development and rollout of 2009 influenza A(H1N1) pandemic vaccine and knowledge challenges for the effective implementation of vaccination programs for COVID-19 and future influenza pandemics.

Methods

A systematic review was conducted searching EMBASE (inception to current date) and PUBMED (from January 2009 to current date) databases for relevant published studies about influenza A(H1N1) pandemic vaccines. A Google search was conducted to identify relevant documents from gray literature. Selected Studies were reviewed and summarized.

Results

A total of 22, comprising of 12 original studies and 10 relevant documents met the inclusion criteria. Fourteen papers reported an initial high demand that outweighed production capacity and caused vaccine shortages. Vaccine procurement and supply were skewed toward high-income countries. Low vaccination rates of about 5%-50% were reported in all studies mainly due to a low-risk perception of getting infected, safety concerns, and the fear of adverse effects.

Conclusions

Safety concerns about the approved H1N1 vaccines resulted in many unsuccessful vaccination campaigns worldwide. Understanding the factors that influence people's decision to accept or refuse vaccination, effective risk communication strategies, adequate resources for vaccine deployment initiatives and building local capacities through shared knowledge and technology transfer may help to improve COVID-19 vaccine uptake and accelerate pandemic control.

Post-Infectious Autoimmunity in the Central (CNS) and Peripheral (PNS) Nervous Systems: An African Perspective

The direct impact and sequelae of infections in children and adults result in significant morbidity and mortality especially when they involve the central (CNS) or peripheral nervous system (PNS). The historical understanding of the pathophysiology has been mostly focused on the direct impact of the various pathogens through neural tissue invasion. However, with the better understanding of neuroimmunology, there is a rapidly growing realization of the contribution of the innate and adaptive host immune responses in the pathogenesis of many CNS and PNS diseases. The balance between the protective and pathologic sequelae of immunity is fragile and can easily be tipped towards harm for the host. The matter of immune privilege and surveillance of the CNS/PNS compartments and the role of the blood-brain barrier (BBB) and blood nerve barrier (BNB) makes this even more complex. Our understanding of the pathogenesis of many post-infectious manifestations of various microbial agents remains elusive, especially in the diverse African setting. Our exploration and better understanding of the neuroimmunology of some of the infectious diseases that we encounter in the continent will go a long way into helping us to improve their management and therefore lessen the burden. Africa is diverse and uniquely poised because of the mix of the classic, well described, autoimmune disease entities and the specifically "tropical" conditions. This review explores the current understanding of some of the para- and post-infectious autoimmune manifestations of CNS and PNS diseases in the African context. We highlight the clinical presentations, diagnosis and treatment of these neurological disorders and underscore the knowledge gaps and perspectives for future research using disease models of conditions that we see in the continent, some of which are not uniquely African and, where relevant, include discussion of the proposed mechanisms underlying pathogen-induced autoimmunity. This review covers the following conditions as models and highlight those in which a relationship with COVID-19 infection has been reported: a) Acute Necrotizing Encephalopathy; b) Measles-associated encephalopathies; c) Human Immunodeficiency Virus (HIV) neuroimmune disorders, and particularly the difficulties associated with classical post-infectious autoimmune disorders such as the Guillain-Barré syndrome in the context of HIV and other infections. Finally, we describe NMDA-R encephalitis, which can be post-HSV encephalitis, summarise other antibody-mediated CNS diseases and describe myasthenia gravis as the classic antibody-mediated disease but with special features in Africa.

A Research and Development (R&D) roadmap for influenza vaccines: Looking toward the future

Improved influenza vaccines are urgently needed to reduce the burden of seasonal influenza and to ensure a rapid and effective public-health response to future influenza pandemics. The Influenza Vaccines Research and Development (R&D) Roadmap (IVR) was created, through an extensive international stakeholder engagement process, to promote influenza vaccine R&D. The roadmap covers a 10-year timeframe and is organized into six sections: virology; immunology; vaccinology for seasonal influenza vaccines; vaccinology for universal influenza vaccines; animal and human influenza virus infection models; and policy, finance, and regulation. Each section identifies barriers, gaps, strategic goals, milestones, and additional R&D priorities germane to that area. The roadmap includes 113 specific R&D milestones, 37 of which have been designated high priority by the IVR expert taskforce. This report summarizes the major issues and priority areas of research outlined in the IVR. By identifying the key issues and steps to address them, the roadmap not only encourages research aimed at new solutions, but also provides guidance on the use of innovative tools to drive breakthroughs in influenza vaccine R&D.

Global access to COVID-19 vaccines: a scoping review of factors that may influence equitable access for low and middle-income countries

OBJECTIVE

To identify the factors contributing to equitable access to COVID-19 vaccines for low and middle-income countries (LMIC).

METHODS

We conducted a scoping review following the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews and a five-stage framework for scoping studies. We performed systematic searches for published peer-reviewed literature in five databases: Medline, Embase, Web of Science, Global Index Medicus and COVID-19 Evidence Epistemonikos (August 2020, updated May 2021).

RESULTS

Systematic selection according to predefined criteria resulted in the final inclusion of 45 peer-reviewed articles, with no limitations on study design or publication type. We derived four key factors that potentially influence equitable access to COVID-19 vaccines in LMICs: (1) collectively agreed global mechanisms or frameworks; (2) bilateral purchasing, contracting, and vaccine prices; (3) vaccine manufacturing that is supported by sharing know-how; and (4) countries' strength in implementing vaccination programmes.

CONCLUSIONS

This scoping review highlights the ongoing challenges for the international community in ensuring equitable access to COVID-19 vaccines for LMICs. The literature suggests that vaccine manufacturing can influence the supply of vaccines, as can the role of patent holders who can influence global governance through their role in the distribution of COVID-19 vaccines. Our findings indicate that including the principles of equitable access throughout vaccine research and development, procurement, scale-up and distribution processes can support equitable access for LMICs. Advances made with mRNA vaccines may have additional benefits in relation to expanding the manufacturing of other vaccine. Finally, the exploration and scale-up of such capacities of LMICs are likely to prove to be a valuable investment, even after the pandemic.

Barriers and activities to implementing or expanding influenza vaccination programs in low- and middle-income countries: A global survey

INTRODUCTION

Despite considerable global burden of influenza, few low- and middle-income countries (LMICs) have national influenza vaccination programs. This report provides a systematic assessment of barriers to and activities that support initiating or expanding influenza vaccination programs from the perspective of in-country public health officials.

METHODS

Public health officials in LMICs were sent a web-based survey to provide information on barriers and activities to initiating, expanding, or maintaining national influenza vaccination programs. The survey primarily included Likert-scale questions asking respondents to rank barriers and activities in five categories.

RESULTS

Of 109 eligible countries, 62% participated. Barriers to influenza vaccination programs included lack of data on cost-effectiveness of influenza vaccination programs (87%) and on influenza disease burden (84%), competing health priorities (80%), lack of public perceived risk from influenza (79%), need for better risk communication tools (77%), lack of financial support for influenza vaccine programs (75%), a requirement to use only WHO-prequalified vaccines (62%), and young children require two vaccine doses (60%). Activities for advancing influenza vaccination programs included educating healthcare workers (97%) and decision-makers (91%) on the benefits of influenza vaccination, better estimates of influenza disease burden (91%) and cost of influenza vaccination programs (89%), simplifying vaccine introduction by focusing on selected high-risk groups (82%), developing tools to prioritize target populations (80%), improving availability of influenza diagnostic testing (79%), and developing collaborations with neighboring countries for vaccine procurement (74%) and regulatory approval (73%). Responses varied by country region and income status.

CONCLUSIONS

Local governments and key international stakeholders can use the results of this survey to improve influenza vaccination programs in LMICs, which is a critical component of global pandemic preparedness for influenza and other pathogens such as coronaviruses. Additionally, strategies to improve global influenza vaccination coverage should be tailored to country income level and geographic location.

Expanding global and national influenza vaccine systems to match the COVID-19 pandemic response

•

Approximately 40% of the global influenza deaths now occur in Africa and Southeast Asia.

•

Opportunities exist to explore synergies in preventing respiratory and cardiovascular diseases.

•

Co-vaccination against both COVID19 and influenza offers promise.

Does having a seasonal influenza program facilitate pandemic preparedness? An analysis of vaccine deployment during the 2009 pandemic

Background:

National seasonal influenza programs have been recommended as a foundation for pandemic preparedness. During the 2009 pandemic, WHO aimed to increase Member States’ equitable access to influenza vaccines through pandemic vaccine donation.

Methods:

This analysis explores whether the presence of a seasonal influenza program contributed to more rapid national submission of requirements to receive vaccine during the 2009 influenza pandemic. Data from 2009 influenza vaccine donation, deployment, and surveillance initiatives were collected during May-September 2018 from WHO archival material. Data about the presence of seasonal influenza vaccine programs prior to 2009 were gathered from the WHO-UNICEF Joint Reporting Form. Cox proportional hazards models were used to assess the relationship between presence of a seasonal influenza program and time to submission of a national deployment and vaccination plan and to vaccine delivery.

Finding:

Of 97 countries eligible to receive WHO-donated vaccine, 83 (86%) submitted national deployment and vaccination plans and 77 (79%) received vaccine. Countries with a seasonal influenza vaccine program were more likely to submit a national deployment and vaccination plan (hazards ratio [HR] 2.1; 95% confidence interval [CI]. Countries with regulatory delays were less likely to receive vaccine than those without these delays (HR 0.4, 95% CI: 0.2–0.6).

Interpretation:

During the 2009 pandemic, eligible countries with a seasonal influenza vaccine program were more ready to receive and use donated vaccines than those without a program. Our findings suggest that robust seasonal influenza vaccine programs increase national familiarity with the management of influenza vaccines and therefore enhance pandemic preparedness.

Factors and considerations for establishing and improving seasonal influenza vaccination of health workers: Report from a WHO meeting, January 16-17, Berlin, Germany

Health workers represent an important target group for seasonal influenza vaccination because of their increased risk of infection as well as the risk of transmitting infection to vulnerable patients in the health care setting. Moreover, seasonal vaccination of health workers contributes to pandemic preparedness. However, many countries, especially in Africa and Asia, do not have policies for health worker influenza vaccination. In countries where such policies exist, vaccination coverage is often low. The World Health Organization (WHO) is developing a manual to guide the introduction of seasonal influenza vaccination of health workers. An Independent External Advisory Group (IEAG) that is advising WHO on the content of the manual met to discuss issues that are relevant and often unique to health worker vaccination. This meeting report summarizes the main issues that were discussed and the outcomes of the discussion. The issues include policy considerations, including the evidence in support of health worker vaccination; categorization and prioritization of health workers; the choice of vaccination strategy; its integration into broader health worker vaccination and occupational health policies; planning and management of vaccination, particularly the approaches for communication and demand generation; and the challenges with monitoring and evaluation of health worker vaccination, especially in low and middle-income countries.

Impact of H1N1 Influenza Vaccination on Child Morbidity in Guinea-Bissau

BACKGROUND

In addition to vaccines' specific effects, vaccines may have non-specific effects (NSEs) altering the susceptibility to unrelated infections. Non-live vaccines have been associated with negative NSEs. In 2010, a campaign with the non-live H1N1-influenza vaccine targeted children 6-59 months in Guinea-Bissau.

METHODS

Bandim Health Project runs a health and demographic surveillance system site in Guinea-Bissau. Using a Cox proportional hazards model, we compared all-cause consultation rates after vs. before the campaign, stratified by participation status.

RESULTS

Among 10 290 children eligible for the campaign, 60% had participated, 18% had not and for 22% no information was obtained. After the H1N1 campaign, the consultation rates tended to decline less for participants [HR = 0.80 (95% confidence interval, CI: 0.75; 0.85)] than for non-participants [HR = 0.68 (95% CI: 0.58; 0.79)], p = 0.06 for same effect.

CONCLUSION

The decline in the vaccinated group may have been smaller than the decline in the non-vaccinated group consistent with H1N1-vaccine increasing susceptibility to unrelated infections.

The partnership for influenza vaccine introduction (PIVI): Supporting influenza vaccine program development in low and middle-income countries through public-private partnerships

Influenza vaccination remains the most effective tool for reducing seasonal influenza disease burden. Few Low and Middle-Income Countries (LMICs) have robust, sustainable annual influenza national vaccination programs. The Partnership for Influenza Vaccine Introduction (PIVI) was developed as a public-private partnership to support LMICs to develop and sustain national vaccination programs through time-limited vaccine donations and technical support. We review the first 5 years of experience with PIVI, including the concept, country progress toward sustainability, and lesson learned. Between 2013 and 2018, PIVI worked with Ministries of Health in 17 countries. Eight countries have received donated vaccines and technical support; of these, two have transitioned to sustained national support of influenza vaccination and six are increasing national support of the vaccine programs towards full transition to local vaccine program support by 2023. Nine additional countries have received technical support for building the evidence base for national policy development and/or program evaluation. PIVI has resulted in increased use of vaccines in partner countries, and early countries have demonstrated progress towards sustainability, suggesting that a model of vaccine and technical support can work in LMICs. PIVI expects to add new country partners as current countries transition to self-reliance.

Assessing global preparedness for the next pandemic: development and application of an Epidemic Preparedness Index

Introduction

Robust metrics for national-level preparedness are critical for assessing global resilience to epidemic and pandemic outbreaks. However, existing preparedness assessments focus primarily on public health systems or specific legislative frameworks, and do not measure other essential capacities that enable and support public health preparedness and response.

Methods

We developed an Epidemic Preparedness Index (EPI) to assess national-level preparedness. The EPI is global, covering 188 countries. It consists of five subindices measuring each country’s economic resources, public health communications, infrastructure, public health systems and institutional capacity. To evaluate the construct validity of the EPI, we tested its correlation with proxy measures for preparedness and response capacity, including the timeliness of outbreak detection and reporting, as well as vaccination rates during the 2009 H1N1 influenza pandemic.

Results

The most prepared countries were concentrated in Europe and North America, while the least prepared countries clustered in Central and West Africa and Southeast Asia. Better prepared countries were found to report infectious disease outbreaks more quickly and to have vaccinated a larger proportion of their population during the 2009 pandemic.

Conclusion

The EPI measures a country’s capacity to detect and respond to infectious disease events. Existing tools, such as the Joint External Evaluation (JEE), have been designed to measure preparedness within a country over time. The EPI complements the JEE by providing a holistic view of preparedness and is constructed to support comparative risk assessment between countries. The index can be updated rapidly to generate global estimates of pandemic preparedness that can inform strategy and resource allocation.

Anticipation and response: pandemic influenza in Malawi, 2009

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.

Epidemiology of Severe Acute Respiratory Illness and Risk Factors for Influenza Infection and Clinical Severity among Adults in Malawi, 2011-2013

Data on the epidemiology of severe acute respiratory illness (SARI) in adults from low-income, high human immunodeficiency virus (HIV) prevalence African settings are scarce. We conducted adult SARI surveillance in Blantyre, Malawi. From January 2011 to December 2013, individuals aged ≥ 15 years with SARI (both inpatients and outpatients) were enrolled at a large teaching hospital in Blantyre, Malawi. Nasopharyngeal aspirates were tested for influenza and other respiratory viruses by polymerase chain reaction. We estimated hospital-attended influenza-positive SARI incidence rates and assessed factors associated with influenza positivity and clinical severity (Modified Early Warning Score > 4). We enrolled 1,126 SARI cases; 163 (14.5%) were positive for influenza. Human immunodeficiency virus prevalence was 50.3%. Annual incidence of hospital-attended influenza-associated SARI was 9.7–16.8 cases per 100,000 population. Human immunodeficiency virus was associated with a 5-fold greater incidence (incidence rate ratio 4.91, 95% confidence interval [CI]: 3.83–6.32). On multivariable analysis, female gender, as well as recruitment in hot, rainy season (December to March; adjusted odds ratios (aOR): 2.82, 95% CI: 1.57–5.06) and cool, dry season (April to August; aOR: 2.47, 95% CI: 1.35–4.15), was associated with influenza positivity, whereas influenza-positive patients were less likely to be HIV-infected (aOR: 0.59, 95% CI: 0.43–0.80) or have viral coinfection (aOR: 0.51, 95% CI: 0.36–0.73). Human immunodeficiency virus infection (aOR: 1.86; 95% CI: 1.35–2.56) and recruitment in hot, rainy season (aOR: 4.98, 95% CI: 3.17–7.81) were independently associated with clinical severity. In this high HIV prevalence population, influenza was associated with nearly 15% of hospital-attended SARI. Human immunodeficiency virus infection is an important risk factor for clinical severity in all-cause and influenza-associated SARI. Expanded access to HIV testing and antiretroviral treatment, as well as targeted influenza vaccination, may reduce the burden of SARI in Malawi and other high HIV prevalence settings.

Respiratory Virus-Associated Severe Acute Respiratory Illness and Viral Clustering in Malawian Children in a Setting With a High Prevalence of HIV Infection, Malaria, and Malnutrition

Background

We used data from 4 years of pediatric severe acute respiratory illness (SARI) sentinel surveillance in Blantyre, Malawi, to identify factors associated with clinical severity and coviral clustering.

Methods

From January 2011 to December 2014, 2363 children aged 3 months to 14 years presenting to the hospital with SARI were enrolled. Nasopharyngeal aspirates were tested for influenza virus and other respiratory viruses. We assessed risk factors for clinical severity and conducted clustering analysis to identify viral clusters in children with viral codetection.

Results

Hospital-attended influenza virus–positive SARI incidence was 2.0 cases per 10 000 children annually; it was highest among children aged <1 year (6.3 cases per 10 000), and human immunodeficiency virus (HIV)–infected children aged 5–9 years (6.0 cases per 10 000). A total of 605 SARI cases (26.8%) had warning signs, which were positively associated with HIV infection (adjusted risk ratio [aRR], 2.4; 95% confidence interval [CI], 1.4–3.9), respiratory syncytial virus infection (aRR, 1.9; 95% CI, 1.3–3.0) and rainy season (aRR, 2.4; 95% CI, 1.6–3.8). We identified 6 coviral clusters; 1 cluster was associated with SARI with warning signs.

Conclusions

Influenza vaccination may benefit young children and HIV-infected children in this setting. Viral clustering may be associated with SARI severity; its assessment should be included in routine SARI surveillance.

Effectiveness and knowledge, attitudes and practices of seasonal influenza vaccine in primary healthcare settings in South Africa, 2010-2013

Objectives

Influenza vaccine effectiveness (VE) and coverage data for sub-Saharan Africa are scarce. Using a test-negative case–control design, we estimated influenza VE annually among individuals with influenza-like illness presenting to an outpatient sentinel surveillance programme in South Africa from 2010 to 2013. A knowledge, attitudes and practices (KAP) influenza vaccine survey of programme clinicians was conducted in 2013.

Sample

In total, 9420 patients were enrolled in surveillance of whom 5344 (56.7%) were included in the VE analysis: 2678 (50.1%) were classified as controls (influenza test-negative) and 2666 (49.9%) as cases (influenza test-positive).

Results

Mean annual influenza vaccine coverage among controls was 4.5% for the four years. Annual VE estimates adjusted for age, underlying medical conditions and seasonality for 2010-2013 were 54.2% (95% confidence interval (CI): 2.4–78.6%), 57.1% (95% CI: 15.5–78.2%), 38.4% (95% CI: −71.7–78.1%) and 87.2% (95% CI: 67.2–95.0%), respectively. The KAP survey showed that >90% of clinicians were familiar with the indications for and the benefits of influenza vaccination.

Conclusions

Our study showed that the vaccine was significantly protective in 2010, 2011 and 2013, but not in 2012 when the circulating A(H3N2) strain showed genetic drift. Vaccine coverage was low despite good clinician knowledge of vaccination indications. Further studies are needed to investigate the reason for the low uptake of influenza vaccine.

Influenza A and Parvovirus B19 Seropositivity Rates in Gabonese Infants

Clinical and epidemiological data from Central Africa on influenza A and parvovirus B19 infections are limited. We analyzed 162 blood samples of infants 3, 9, 15, and 30 months of age for IgG antibodies against both pathogens. Antibody responses were 0, 3.7%, 12.3%, and 20.4% against influenza A; and 1.2%, 2.5%, 3.1%, and 9.3% against parvovirus B19, respectively. Seropositivity rates were 89.5 (95% confidence interval [CI]: 59-120.1) and 38.2 (95% CI: 18.9-57.6)/1,000 person-years at risk for influenza A and parvovirus B19, respectively. Our data add to the understanding of the epidemiology of both conditions.

Sentinel surveillance of influenza in Burkina Faso: identification of circulating strains during 2010-2012

Background

Although influenza surveillance has recently been improved in some sub-Saharan African countries, no information is yet available from Burkina Faso.

Objectives

Our study was the first to determine the prevalence of influenza viruses circulating in Burkina Faso through a sentinel surveillance system.

Methods

We conducted sentinel surveillance with oropharyngeal (OP) swabs collected from outpatients (1 month to 83 years) from six sites in Bobo-Dioulasso and Ouagadougou, among patients meeting the WHO/CDC case definition for influenza-like illness (ILI; fever ≥38°C, and cough and/or sore throat in the absence of other diagnosis) from July 2010 to May 2012. Influenza viruses were detected by real-time RT-PCR using CDC primers, probes, and protocols.

Results

The first three ILI cases were enrolled each day; of 881 outpatients with ILI enrolled and sampled, 58 (6·6%) tested positive for influenza viruses (29 influenza A and 29 influenza B). Among the influenza A viruses, 55·2% (16/29) were influenza A (H1N1)pdm09 and 44·8% (13/29) were seasonal A (H3N2). No cases of seasonal A/H1N1 were detected. Patients within 0–5 years and 6–14 years were the most affected, comprising 41·4% and 22·4% laboratory-confirmed influenza cases, respectively. Influenza infections occurred during both the dry, dusty Harmattan months from November to March and the rainy season from June to October with peaks in January and August.

Conclusions

This surveillance was the first confirming the circulation of influenza A (H1N1)pdm09, A/H3N2, and influenza B viruses in humans in Burkina Faso.

Prevention and Control of Influenza Viruses

The 2003–2004 outbreaks of highly pathogenic avian influenza (HPAI) have proven to be disastrous to the regional poultry industry in Asia, and have raised serious worldwide public health apprehension regarding the steps that should be taken to urgently control HPAI. Control measures must be taken based on the principles of biosecurity and disease management and at the same time making public aware of the precautionary measures at the verge of outbreak. Creation of protection and surveillance zones, various vaccination strategies viz. routine, preventive, emergency, mass and targeted vaccination programmes using live, inactivated and recombinant vaccines are the common strategies adopted in different parts of the globe. The new generation vaccines include recombinant vaccines and recombinant fusion vaccine. The pro-poor disease control programmes, giving compensation and subsidies to the farmers along with effective and efficient Veterinary Services forms integral part of control of HPAI. Following biosecurity principles and vaccination forms integral part of control programme against swine and equine influenza as well. Use of neuraminidase (NA) inhibitors (Zanamivir and Oseltamivir) for the treatment of human influenza has been widely accepted worldwide. The threat of increasing resistance of the flu viruses to these antivirals has evoked interest in the development of novel antiviral drugs for influenza virus such as inhibitors of cellular factors and host signalling cascades, cellular miRNAs, siRNA and innate immune peptides (defensins and cathelicidins). Commercial licensed inactivated vaccines for humans against influenza A and B viruses are available consisting of three influenza viruses: influenza type A subtype H3N2, influenza type A subtype H1N1 (seasonal) virus strain and influenza type B virus strain. As per WHO, use of tetravaccine consisting of antigens of influenza virus serotypes H3N2, H1N1, B and H5 is the most promising method to control influenza pandemic. All healthy children in many countries are required to be vaccinated between 6 and 59 months of age. The seasonal vaccines currently used in humans induce strain-specific humoral immunity as the antibodies. Universal influenza virus vaccines containing the relatively conserved ectodomain of M2 (M2e), M1, HA fusion peptide and stalk domains, NA, NP alone or in combination have been developed which have been shown to induce cross-protection. The T cell-based vaccines are another recent experimental approach that has been shown to elicit broad-spectrum heterosubtypic immunity in the host. As far as HPAI is concerned, various pandemic preparedness strategies have been documented.