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Seasonal influenza vaccines protect against 3 (trivalent influenza vaccine [IIV3]) or 4 (quadrivalent influenza vaccine [IIV4]) viruses. IIV4 costs more than IIV3, and there is a trade-off between incremental cost and protection. This is especially the case in low- and middle-income countries (LMICs) with limited budgets; previous reviews have not identified studies of IIV4-IIV3 comparisons in LMICs. We summarized the literature that compared health and economic outcomes of IIV4 and IIV3, focused on LMICs.We systematically searched 5 databases for articles published before October 6, 2021, that modeled health or economic effects of IIV4 versus IIV3. We abstracted data and compared findings among countries and models.Thirty-eight studies fit our selection criteria; 10 included LMICs. Most studies (N = 31) reported that IIV4 was cost-saving or cost-effective compared with IIV3; we observed no difference in health or economic outcomes between LMICs and other countries. Based on cost differences of influenza vaccines, only one study compared coverage of IIV3 with IIV4 and reported that the maximum IIV4 price that would still yield greater public health impact than IIV3 was 13% to 22% higher than IIV3.When vaccination coverage with IIV4 and IIV3 is the same, IIV4 tends to be not only more effective but more cost-effective than IIV3, even with relatively high price differences between vaccine types. Alternatively, where funding is limited as in most LMICs, higher vaccine coverage can be achieved with IIV3 than IIV4, which could result in more favorable health and economic outcomes.

IntroductionHistorically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness, (2) costs of influenza vaccination programs, and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist.MethodsWe performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus using a combination of the following key words: “influenza” AND “cost” OR “economic.” The search included studies with publication years 2012 through 2021. We abstracted general study characteristics and data specific to each of the three areas of review.ResultsOf 50 included studies, 24 presented data on cost-effectiveness, 23 on cost-of-illness, and four on program costs. Represented countries were classified as upper-middle income (UMIC; n=11), lower-middle income (LMIC; n=7), and low-income (LIC; n=3). The most evaluated target groups were children (n=26 studies), older adults (n=16), and persons with chronic medical conditions (n=12); fewer studies evaluated pregnant persons (n=8), healthcare workers (n=4), and persons in congregate living settings (n=1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest total costs, as a percent of gross domestic product and national health expenditure, were reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (83%) interpreted at least one scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study.ConclusionsContinued evaluation of the economic burden of influenza illness and costs and cost-effectiveness of influenza vaccination, particularly in low-income countries and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed; use of standardized methodology could facilitate pooling across settings. Robust, global economic data are critical to design and maintain sustainable influenza vaccination programs.Summary boxWhat is already known on this topicPrior systematic reviews and surveys have demonstrated a need for economic data on influenza vaccination from low- and middle-income countries to inform program implementation and expansion. Standardized tools and guidance have become available in recent years to guide economic evaluations for influenza illness and vaccination in low-and middle-income countries.What this study addsThis article summarizes the literature on costs of influenza illness, costs of influenza vaccination programs, and vaccination cost-effectiveness from low- and middle-income country settings during 2012–2021.How this study might affect research, practice, or policyThe findings suggest value-for-money for influenza vaccination and increased interest in economic evaluations in recent years, but continued, standardized evaluation of costs and cost-effectiveness is needed, particularly from low-income countries and for underrepresented target groups.

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. publishedVersion

Background During the 2009 influenza A(H1N1)pdm09 pandemic, 77 countries received donated monovalent A(H1N1)pdm09 vaccine through the WHO Pandemic Influenza A(H1N1) Vaccine Deployment Initiative. However, 47% did not receive their first shipment until after the first wave of virus circulation, and 8% did not receive their first shipment until after the WHO declared the end of the pandemic. Arguably, these shipments were too late into the pandemic to have a substantial effect on virus transmission or disease burden during the first waves of the pandemic. Objectives In order to evaluate the potential benefits of earlier vaccine availability, we estimated the number of illnesses and deaths that could be averted during a 2009-like influenza pandemic under five different vaccine-availability timing scenarios. Methods We adapted a model originally developed to estimate annual influenza morbidity and mortality burden averted through US seasonal vaccination and ran it for five vaccine availability timing scenarios in nine low- and middle-income countries that received donated vaccine. Results Among nine study countries, we estimated that the number of averted cases was 61–216,197 for actual vaccine receipt, increasing to 2,914–283,916 had vaccine been available simultaneously with the United States. Conclusions Earlier delivery of vaccines can reduce influenza case counts during a simulated 2009-like pandemic in some low- and middle-income countries. For others, increasing the number of cases and deaths prevented through vaccination may be dependent on factors other than timely initiation of vaccine administration, such as distribution and administration capacity.

While seasonal influenza vaccines (SIV) remain the best method to prevent influenza-associated illnesses, implementing SIV programs may benefit countries beyond disease reduction, strengthening health systems and national immunization programs, or conversely, introduce new challenges. Few studies have examined perceived impacts of SIV introduction beyond disease reduction on health systems; understanding such impacts will be particularly salient in the context of COVID-19 vaccine introduction. We collected qualitative data from key informants-Partnership for Influenza Vaccine Introduction (PIVI) contacts in six middle-income PIVI vaccine recipient countries-to understand perceptions of ancillary benefits and challenges from SIV implementation. Respondents reported benefits associated with SIV introduction, including improved attitudes to SIV among risk groups (characterized by increased demand) and perceptions that SIV introduction improved relationships with other ministries and collaboration with mass media. Challenges included sustaining investment in SIV programs, as vaccine supply did not always meet coverage goals, and managing SIV campaigns.

INTRODUCTION The World Health Organization (WHO) recommends vaccination of health workers against influenza, but uptake in low-resource settings remains low. To complement routine global data collection efforts we conducted a detailed survey on influenza vaccination policies for health workers in low-income and middle-income countries (LMICs) in early 2020. METHODS Health worker vaccination policy data were collected via a web-based survey tool sent to Expanded Programme on Immunization managers or equivalent managers of all eligible countries. High-income countries and countries with active civil war were excluded from the participation. The survey was sent by email to 109 LMICs in all WHO Regions to invite participation. Data were analyzed by World Bank income category and WHO Region. Statistical methods were applied to assess mean vaccination rates across countries. RESULTS Sixty-eight (62%) out of 109 invited LMICs were studied. Thirty-five (51.5%) reported to have a policy for influenza vaccination of health workers. Vaccinations were voluntary in 23 countries (66%), mandatory in 4 (11%), while in 8 countries (23%) mixed vaccination policies existed. A mechanism to estimate vaccine uptake existed in 26 countries (74%). Low-income and African Region countries were less likely to have influenza vaccination policies for health workers (p-values

In March 2019, a group of global health leaders with expertise in influenza, vaccinology and pandemic preparedness was convened for a meeting titled "Shaping Meeting to explore the value of a coordinated work plan for epidemic and pandemic influenza vaccine preparedness." Influenza epidemics occur annually in every country in the world, resulting in significant global burden of illness and deaths. While every country is effected, most deaths and severe disease occur in low- and lower middle-income countries (LIC and LMIC). Influenza immunization programs that limit the burden of disease, deaths, and reduce economic impact are a fundamental public health intervention for seasonal epidemics. In addition, they provide the experience, systems and infrastructure for the timely and efficient use of vaccines and other medical countermeasures critical for effective pandemic responses. Pandemic influenza response activities, including vaccination efforts, will be most effective if used and practiced regularly. Consequently, countries with seasonal influenza prevention and control programs should be better prepared for, and have more effective pandemic responses than countries without such programs. A decade after the 2009 pandemic, despite ongoing prevention efforts, most LICs and LMICs still lack access to robust seasonal influenza immunization programs. Given this current state, meeting participants concluded that there is critical need to advance the expansion and strengthening of seasonal influenza immunization programs in LICs and LMICs not only to reduce the economic and public health effects of annual influenza epidemics, but also to increase preparedness to mitigate the threat of future pandemics and improve global heath security. Many government and private sectors, in a whole of government approach, need to be working together to support and advance countries' epidemic and pandemic influenza capacities preparedness objectives. Accomplishment of these objectives can be achieved with a coordinated work plan developed and guided by an alliance of international stakeholders, to include, among others, government, and nongovernment organization representation, civil society representatives, vaccine manufacturers, international organizations, and health security and influenza experts.

Conventional influenza vaccines are designed to stimulate neutralizing antibodies against immunodominant but highly variable hemagglutinin antigens. Inherent limitations include suboptimal protection against rapidly changing seasonal influenza viruses and a lack of protection against antigenically novel pandemic influenza. New technologies for developing influenza vaccines that induce more broadly protective and durable immunity are a growing area of research and focus on a variety of approaches, including targeting conserved antigens and stimulating cross-reactive T cell responses. This review highlights a new effort to track the development of universal influenza vaccine technologies. The Universal Influenza Vaccine Technology Landscape is intended to provide stakeholders and funders with a common source of information to monitor research progress and identify opportunities for informed investments and collaboration.

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. Funding N/A.

Influenza vaccination is a key public health intervention for pandemic influenza as it can limit the burden of disease, especially in high-risk groups, minimize social disruption and reduce economic impact.1 In the event of an influenza pandemic, large-scale production, distribution and administration of pandemic vaccines in the shortest time possible is required. In addition, monitoring vaccine effectiveness, coverage and adverse events following immunization (AEFI) is important. Since seasonal influenza vaccination programmes require annual planning in each of these areas, establishing and strengthening annual influenza programmes will contribute to pandemic preparedness.2 This paper presents efforts made in the World Health Organization (WHO) Western Pacific Region to improve seasonal influenza vaccination and pandemic preparedness.

Background Pregnant women, healthcare workers (HW), and adults >= 60 years have shown an increased vulnerability to seasonal influenza virus infections and/or complications. In 2012, the Lao People's Democratic Republic (Lao PDR) initiated a national influenza vaccination program for these target groups. A cost-effectiveness evaluation of this program was undertaken to inform program sustainability. Methods We designed a decision-analytical model and collected influenza-related medical resource utilization and cost data, including indirect costs. Model inputs were obtained from medical record abstraction, interviews of patients and staff at hospitals in the national influenza sentinel surveillance system and/or from literature reviews. We compared the annual disease and economic impact of influenza illnesses in each of the target groups in Lao PDR under scenarios of no vaccination and vaccination, and then estimated the cost-effectiveness of the vaccination program. We performed sensitivity analyses to identify influential variables. Results Overall, the vaccination of pregnant women, HWs, and adults >= 60 years could annually save 11,474 doctor visits, 1,961 days of hospitalizations, 43,027 days of work, and 1,416 life-years due to laboratory-confirmed influenza illness. After comparing the total vaccination program costs of 23.4 billion Kip, to the 18.4 billion Kip saved through vaccination, we estimated the vaccination program to incur a net cost of five billion Kip (599,391 USD) annually. The incremental cost per life-year saved (ICER) was 44 million Kip (5,295 USD) and 6.9 million Kip (825 USD) for pregnant women and adults >= 60 years, respectively. However, vaccinating HWs provided societal cost-savings, returning 2.88 Kip for every single Kip invested. Influenza vaccine effectiveness, attack rate and illness duration were the most influential variables to the model. Conclusion Providing influenza vaccination to HWs in Lao PDR is cost-saving while vaccinating pregnant women and adults >= 60 is cost-effective and highly cost-effective, respectively, per WHO standards.

Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results.

Background The estimated association of maternal influenza vaccination and birth outcomes may be sensitive to methods used to define preterm birth or small‐for‐gestational age (SGA). Methods In a cohort of pregnant women in Lao People's Democratic Republic, we estimated gestational age from: (a) date of last menstrual period (LMP), (b) any prenatal ultrasound, (c) first trimester ultrasound, (d) Ballard Score at delivery, and (e) an algorithm combining LMP and ultrasound. Infants were classified as SGA at birth using a Canadian, global, and equation‐based growth reference. We estimated the association of maternal influenza vaccination and birth outcomes, by influenza activity, using multivariable log‐binomial regression and Cox proportional hazards regression with vaccination as a time‐varying exposure. Results The frequency of preterm birth in the cohort varied by method to estimate gestational age, from 5% using Ballard Score to 15% using any ultrasound. Using LMP, any ultrasound, or the algorithm, we found statistically significant reductions in preterm birth among vaccinated women during periods of high influenza activity and statistically significant increases in SGA, using a Canadian growth reference. We did not find statistically significant associations with SGA when using global or equation‐based growth references. Conclusions The association of maternal influenza vaccination and birth outcomes was most affected by the choice of a growth reference used to define SGA at birth. The association with pre‐term birth was present and consistent across multiple statistical approaches. Future studies of birth outcomes, specifically SGA, should carefully consider the potential for bias introduced by measurement choice.

In response to global interest in the development of a universal influenza vaccine, the Bill & Melinda Gates Foundation, PATH, and the Global Funders Consortium for Universal Influenza Vaccine Development convened a meeting of experts (London, UK, May 2018) to assess the role of a standardized controlled human influenza virus infection model (CHIVIM) towards the development of novel influenza vaccine candidates. This report (in two parts) summarizes those discussions and offers consensus recommendations. Part 1 covers challenge virus selection, regulatory and ethical considerations, and issues concerning standardization, access, and capacity. This article (Part 2) summarizes the discussion and recommendations concerning CHIVIM methods. The panelists identified an overall need for increased standardization of CHIVIM trials, in order to produce comparable results that can support universal vaccine licensure. Areas of discussion included study participant selection and screening, route of exposure and dose, devices for administering challenge, rescue therapy, protection of participants and institutions, clinical outcome measures, and other considerations. The panelists agreed upon specific recommendations to improve the standardization and usefulness of the model for vaccine development. Experts agreed that a research network of institutions working with a standardized CHIVIM could contribute important data to support more rapid development and licensure of novel vaccines capable of providing long-lasting protection against seasonal and pandemic influenza strains.

National Immunization Technical Advisory Groups (NITAGs) are multidisciplinary national experts who provide independent, evidence-informed vaccine policy recommendations to national health authorities. An essential NITAG function is to ensure that these decisions are grounded in the best available evidence generated through a systematic, transparent process. However, in many low- and middle-income countries (LMICs), experience with this decision making method is limited. The Task Force for Global Health manages the Partnership for Influenza Vaccine Introduction (PIVI) program in collaboration with the Centers for Disease Control and Prevention, Ministries of Health, corporate partners and others. During 2017, PIVI worked with its country partners and the World Health Organization regional and local offices to assess NITAG strengthening needs and to provide technical assistance in 7 LMIC countries (Laos Peoples Democratic Republic, Mongolia, Vietnam, Armenia, Cote d’Ivoire; Moldova and the Republic of Georgia). Our workshops supported general NITAG capacity building and the evidence-based review process using vaccines of interest to the country. For NITAGs reviewing evidence on seasonal influenza, we developed an influenza resource package to support their review and provide country-relevant information in an easy to use format. Of the seven NITAGs trained, six have applied some of the concepts learnt: revision or development of formal transparent, systematic procedures for their operations; preparation of recommendations on seasonal influenza vaccination using quality-assessed data from systematic searches and local data; and have applied the principles learned for making other new vaccine recommendations. Our experience confirms that LMIC NITAGs are considerably under-resourced without adequate technical support or access to global peer-reviewed literature. Ongoing support from NITAG partners must be secured and creative approaches might be needed to help countries achieve the GVAP 2020 target and support development of sustainable vaccine policies and programs.

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.

Background We evaluated a Russian-backbone, live, attenuated influenza vaccine (LAIV) for immunogenicity and viral shedding in a randomized, placebo-controlled trial among Bangladeshi children. Methods Healthy children received a single, intranasal dose of LAIV containing the 2011–2012 recommended formulation or placebo. Nasopharyngeal wash (NPW) specimens were collected on days 0, 2, 4, and 7. Reverse transcription polymerase chain reactions and sequencing identified the influenza virus (vaccine or wild-type). On days 0 and 21, blood specimens were collected to assess immunogenicity using hemagglutination inhibition, microneutralization, and immunoglobulin A (IgA) and G enzyme-linked immunosorbent assays (ELISAs); NPW specimens were also collected to assess mucosal immunogenicity using kinetic IgA ELISA. Results We enrolled 300 children aged 24 through 59 months in the immunogenicity and viral shedding analyses. Among children receiving LAIV, 45% and 67% shed A/H3N2 and B vaccine strains, respectively. No child shed A/H1N1 vaccine strain. There were significantly higher day 21 geometric mean titers (GMTs) for the LAIV, as compared to the placebo groups, in all immunoassays for A/H3N2 and B (log10 titer P < .0001; GMT Ratio >2.0). Among immunoassays for A/H1N1, only the mucosal IgA GMT was significantly higher than placebo at day 21 (log10 titer P = .0465). Conclusions Children vaccinated with LAIV had serum and mucosal antibody responses to A/H3N2 and B, but only a mucosal IgA response to A/H1N1. Many children shed A/H3N2 and B vaccine strains, but none shed A/H1N1. More research is needed to determine the reason for decreased LAIV A/H1N1 immunogenicity and virus shedding. Clinical Trials Registration NCT01625689., In this Phase II trial of live, attenuated influenza vaccine in Bangladeshi children, we detected post-vaccination antibody responses to A/H3N2 and B viruses and viral shedding. However, we detected a reduced post-vaccination antibody response to A/H1N1 and no viral shedding.

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.

Background Influenza causes substantial morbidity and mortality worldwide, however, reliable burden estimates from developing countries are limited, including India. We aimed to quantify influenza-associated mortality for India utilizing 2010-2013 nationally representative data sources for influenza virus circulation and deaths. Methods Virological data were obtained from the influenza surveillance network of 10 laboratories led by National Institute of Virology, Pune covering eight states from 2010-2013. Death data were obtained from the nationally representative Sample Registration System for the same time period. Generalized linear regression with negative binomial distribution was used to model weekly respiratory and circulatory deaths by age group and proportion of specimens positive for influenza by subtype; excess deaths above the seasonal baseline were taken as an estimate of influenza-associated mortality counts and rates. Annual excess death rates and the 2011 India Census data were used to estimate national influenza-associated deaths. Results Estimated annual influenza-associated respiratory mortality rates were highest for those ≥65 years (51.1, 95% confidence interval (CI) = 9.2-93.0 deaths/100 000 population) followed by those

Background Healthcare workers (HCWs) are at high risk of exposure and transmission of infectious respiratory pathogens like influenza. Despite the potential benefits, safety and efficacy of influenza vaccination, vaccines are still underutilized in Africa, including among HCWs. Method From May-June 2018, we conducted a cross-sectional, self-administered, written survey among HCWs from seven counties in Kenya and assessed their knowledge attitudes and perceptions towards pandemic influenza disease and vaccination. Using regression models, we assessed factors that were associated with the HCW’s knowledge of pandemic influenza and vaccination. Results A total of 2,035 HCWs, representing 49% of the targeted respondents from 35 health facilities, completed the question. Sixty eight percent of the HCWs had ever heard of pandemic influenza, and 80.0% of these were willing to receive pandemic influenza vaccine if it was available. On average, Kenyan HCWs correctly answered 55.0% (95% CI 54.0–55.9) of the questions about pandemic influenza and vaccination. Physicians (65.6%, 95% CI 62.5–68.7) and pharmacists (61.7%, 95% CI 57.9–65.5) scored higher compared to nurses (53.1%, 95% CI 51.7–54.5). HCWs with 5 or more years of work experience (55.8, 95% CI 54.5–57.0) had marginally higher knowledge scores compared to those with less experience (53.9%, 95% CI 52.5–55.3). Most participants who were willing to receive pandemic influenza vaccine did so to protect their relatives (88.7%) or patients (85.9%). Conclusion Our findings suggest moderate knowledge of pandemic influenza and vaccination by HCWs in Kenya, which varied by cadre and years of work experience. These findings highlight the need for continued in-service health education to increase the HCW’s awareness and knowledge of pandemic influenza to increase acceptance of influenza vaccination in the case of a pandemic.

Prior to updating global influenza-associated mortality estimates, the World Health Organization convened a consultation in July 2017 to understand differences in methodology and implications for results of 3 influenza mortality projects from the US Centers for Disease Control and Prevention (CDC), the Netherlands Institute for Health Service Research’s Global Pandemic Mortality Project II (GLaMOR), and the Institute for Health Metrics and Evaluation (IHME). The expert panel reviewed estimates and discussed differences in data sources, analysis, and modeling assumptions. We performed a comparison analysis of the estimates. Influenza-associated respiratory death counts were comparable between CDC and GLaMOR; the IHME estimate was considerably lower. The greatest country-specific influenza-associated fold differences in mortality rate between CDC and IHME estimates and between GLaMOR and IHME estimates were among countries in Southeast Asia and the Eastern Mediterranean region. The data envelope used for the calculation was one of the major differences (CDC and GLaMOR: all respiratory deaths; IHME: lower-respiratory infection deaths). With the assumption that there is only one cause of death for each death, IHME estimates a fraction of the full influenza-associated respiratory mortality that is measured by the other 2 groups. Wide variability of parameters was observed. Continued coordination between groups could assist with better understanding of methodological differences and new approaches to estimating influenza deaths globally.

Influenza has long been a global public health priority because of the threat of another global pandemic. Although data are available for the annual burden of seasonal influenza in many developed countries, fewer disease burden data are available for low-income and tropical countries. In recent years, however, the surveillance systems created as part of national pandemic preparedness efforts have produced substantial data on the epidemiology and impact of influenza in countries where data were sparse. These data are leading to greater interest in seasonal influenza, including implementation of vaccination programs. However, a lack of quality data on severe influenza, nonrespiratory outcomes, and high-risk groups, as well as a need for better mathematical models and economic evaluations, are some of the major gaps that remain. These gaps are the focus of multilateral research and surveillance efforts that will strengthen global efforts in influenza control in the future.

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.

The database of the Global Influenza B Study was created by collecting surveillance datasets from each of the participating countries. These national datasets are owned by the participating countries, and thus cannot be shared publicly. Researchers interested in obtaining the country-specific datasets may contact the individuals listed below for further details regarding data access.Argentina (Santa Fe Province): Gabriela Kusznierz (labconi@yahoo.com.ar)Australia: Kate Pennington (kate.pennington@health.gov.au)Bhutan: Sonam Wangchuk (swangchuk@health.gov.bt)Brazil: Cláudio Maierovitch Pessanha Henriques (claudio.henriques@saude.gov.br)Cameroon: Guy Vernet (vernet@pasteur-yaounde.org)Chile: Rodrigo Fasce (rfasce@ispch.cl)China: Feng Luzhao (fenglz@chinacdc.cn)Costa Rica: Alexey W. Clara (wclara@cdc.gov)Ecuador: Alfredo Bruno (alfredobruno@yahoo.es)El Salvador: Alexey W. Clara (wclara@cdc.gov)England: Maria Zambon (maria.zambon@phe.gov.uk)Guatemala: Alexey W. Clara (wclara@cdc.gov)Honduras: Alexey W. Clara (wclara@cdc.gov)Indonesia: Herman Kosasih (hermaninarespond@gmail.com)Italy: Caterina Rizzo (caterina.rizzo@iss.it)Ivory Coast: Herve A. Kadjo (hervekadjo@pasteur.ci)Kazakhstan: Gulzhan Muratbayeva (hnv2@cdc.gov)Kenya: Joshua Mott (zud9@cdc.gov)Madagascar: Jean-Michel Heraud (jmheraud@pasteur.mg)Morocco: Amal Barakat (amal.barakat@yahoo.fr)New Zealand: Sue Huang (sue.huang@esr.cri.nz)Nicaragua: Alexey W. Clara (wclara@cdc.gov)Panama: Alexey W. Clara (wclara@cdc.gov)Portugal: Ana Paula Rodrigues (ana.rodrigues@insa.min-saude.pt)Singapore: Vernon Lee (vernonljm@hotmail.com)South Africa: Cheryl Cohen (cherylc@nicd.ac.za)Turkey: Meral Akcay Ciblak (ciblakm@yahoo.com)Ukraine: Alla Mironenko (miralla@ukr.net)Viet Nam: Le Thi Quinh Mai (lom9@hotmail.com); International audience; BACKGROUND:Influenza disease burden varies by age and this has important public health implications. We compared the proportional distribution of different influenza virus types within age strata using surveillance data from twenty-nine countries during 1999-2014 (N=358,796 influenza cases).METHODS:For each virus, we calculated a Relative Illness Ratio (defined as the ratio of the percentage of cases in an age group to the percentage of the country population in the same age group) for young children (0-4 years), older children (5-17 years), young adults (18-39 years), older adults (40-64 years), and the elderly (65+ years). We used random-effects meta-analysis models to obtain summary relative illness ratios (sRIRs), and conducted meta-regression and sub-group analyses to explore causes of between-estimates heterogeneity.RESULTS:The influenza virus with highest sRIR was A(H1N1) for young children, B for older children, A(H1N1)pdm2009 for adults, and (A(H3N2) for the elderly. As expected, considering the diverse nature of the national surveillance datasets included in our analysis, between-estimates heterogeneity was high (I2>90%) for most sRIRs. The variations of countries' geographic, demographic and economic characteristics and the proportion of outpatients among reported influenza cases explained only part of the heterogeneity, suggesting that multiple factors were at play.CONCLUSIONS:These results highlight the importance of presenting burden of disease estimates by age group and virus (sub)type.

BACKGROUND Nicaragua implemented an influenza vaccination program for pregnant women with high-risk obstetric conditions in 2007. In 2014, the recommendation of influenza vaccination expanded to include all pregnant women. Given the expansion in the recommendation of vaccination, we evaluated knowledge, attitudes and practices of pregnant women and their healthcare providers towards influenza vaccination and its recommendation. METHODS We conducted surveys among pregnant women and their healthcare providers from June to August 2016 at two hospitals and 140 health facilities in Managua. The questions were adapted from the U.S. national CDC influenza survey and related to knowledge, attitudes and practices about influenza vaccination and barriers to vaccination. We analyzed reasons for not receiving vaccination among pregnant women as well as receipt of vaccination recommendation and offer by their healthcare providers. RESULTS Of 1,303 pregnant women enrolled, 42% (5 4 5) reported receiving influenza vaccination in the 2016 season. Of those who reported not receiving vaccination, 46% indicated barriers to vaccination. Pregnant women who were vaccinated were more likely to be aware of the recommendation for vaccination and the risks of influenza illness during pregnancy and to perceive the vaccine as safe and effective, compared to unvaccinated pregnant women (p-values