INTRODUCTION: Data about healthcare workers' (HCW) willingness to accept and recommend seasonal influenza vaccination in countries without influenza vaccination programs are limited. METHODS: We conducted a cross-sectional survey in 7 of the 47 counties in Kenya to examine HCW's knowledge and perceptions of seasonal influenza disease and vaccination. We aimed to enroll all HCW who deliver clinical services directly or peripherally to patients from 5 health facilities in each county. We used chi-square tests and mixed effects logistic regression to identify variables associated with HCW's willingness to accept and recommend seasonal influenza vaccination. RESULTS: From May-June 2018, we enrolled 2035 HCW, representing 49.0 % of targeted respondents from 35 facilities. Most HCW (82.1 %) were from public health facilities. Among the HCW who had heard of seasonal influenza, 87.3 % (1420/1627) believed it can cause severe illness. Most HCW (1076/1209; 89.0 %) were willing to receive a seasonal influenza vaccine if it was recommended for them and provided for free, and 91.4 % (1441/1576) would vaccinate or recommend vaccination to their patients if vaccine was available. Only 17.6 % (213/1212) reported having ever received a seasonal influenza vaccine. HCW who believed that influenza could cause severe illness (aOR 1.8; 95 % CI 1.0-3.2) and that people around them would be better protected from influenza illness if HCW are vaccinated (aOR 3.1; 95 % CI 2.0-4.9) were more likely to report willingness to accept vaccination. HCW from private health facilities (aOR 2.2; 95 % CI 1.3-6.4), and those who believed that people around them are better protected if HCW are vaccinated (aOR 3.5; 95 % CI 2.2-5.8) were more likely to report willingness to vaccinate or recommend vaccination to patients. CONCLUSION: Our findings suggest favorable attitudes among HCW towards seasonal influenza vaccination, many of whom are motivated by the desire to protect the health of others around them.

On November 13-14, 2023, the National Institute of Allergy and Infectious Diseases (NIAID) in partnership with the Task Force for Global Health, Flu Lab, the Canadian Institutes of Health Research, and the Centers for Disease Control and Prevention convened a meeting on controlled human influenza virus infection model (CHIVIM) studies to review the current research landscape of CHIVIM studies and to generate actionable next steps. Presentations and panel discussions highlighted CHIVIM use cases, regulatory and ethical considerations, innovations, networks and standardization, and the utility of using CHIVIM in vaccine development. This report summarizes the presentations, discussions, key takeaways, and future directions for innovations in CHIVIMs. Experts agreed that CHIVIM studies can be valuable for the study of influenza infection, immune response, and transmission. Furthermore, they may have utility in the development of vaccines and other medical countermeasures; however, the use of CHIVIMs to de-risk clinical development of investigational vaccines should employ a cautious approach. Endpoints in CHIVIM studies should be tailored to the specific use case. CHIVIM studies can provide useful supporting data for vaccine licensure but are not required and do not obviate the need for the conduct of field efficacy trials. Future directions in this field include the continued expansion of capacity to conduct CHIVIM studies, development of a broad panel of challenge viruses and assay reagents and standards that can be shared, streamlining of manufacturing processes, the exploration of targeted delivery of virus to the lower respiratory tract, efforts to more closely replicate natural influenza disease in CHIVIM, alignment on a definition of breadth to facilitate development of more broadly protective/universal vaccine approaches, and continued collaboration between stakeholders.

BACKGROUND: Although healthcare personnel (HCP) are targeted for influenza vaccination they typically underutilize vaccines especially in low- and middle-income countries. We explored knowledge, attitudes, and practices of HCP about seasonal influenza vaccines (SIV) to identify factors associated with and modifiable barriers to SIV uptake. METHODS: We pooled individual-level data from cross-sectional surveys about SIV conducted among health workers in 12 low- and middle- income countries during 2018-2020 (i.e., Albania, Armenia, Cote d'Ivoire, Kenya, Kyrgyzstan, Lao PDR, Lebanon, Morocco, North Macedonia, Tunisia, Tajikistan, and Uganda). Eleven countries used a standard protocol and questionnaire based on the Health Belief Model to measure perceptions of susceptibility and severity of influenza disease, benefits of, barriers to, and motivators for vaccination. We analyzed attitudes and perceptions among HCP, including acceptance of vaccine for themselves and willingness to recommend vaccines to patients, grouped by the presence/absence of a national influenza vaccination program. Models were adjusted for geographic region. RESULTS: Our analysis included 10,281 HCP from 12 countries representing four of the six World Health Organization regions: African, Eastern Mediterranean, European, and Western Pacific. The sample was distributed across low income (LIC) (3,183, 31 %), lower-middle (LMIC) (4,744, 46 %), and upper-middle income (UMIC) (2,354, 23 %) countries. Half (50 %) of the countries included in the analysis reported SIV use among HCP in both the year of and the year preceding data collection while the remainder had no influenza vaccination program for HCP. Seventy-four percent (6,341) of HCP reported that they would be willing to be vaccinated if the vaccine was provided free of charge. HCP in LICs were willing to pay prices for SIV representing a higher percentage of their country's annual health expenditure per capita (6.26 % [interquartile range, IQR: 3.13-12.52]) compared to HCP in LMICs and UMICs. HCP in countries with no SIV program were also willing to pay a higher percentage for SIV (5.01 % [IQR: 2.24-8.34]) compared to HCP in countries with SIV programs.. Most (85 %) HCP in our analysis would recommend vaccines to their patients, and those who would accept vaccines for themselves were 3 times more likely to recommend vaccines to their patients (OR 3.1 [95 % CI 1·8, 5·2]). CONCLUSION: Increasing uptake of SIV among HCP can amplify positive impacts of vaccination by increasing the likelihood that HCP recommend vaccines to their patients. Successful strategies to achieve increased uptake of vaccines include clear guidance from health authorities, interventions based on behavior change models, and access to vaccine free-of-charge.

Vaccination of healthcare workers against influenza is a crucial strategy to reduce transmission amongst vulnerable populations, facilitate patient uptake of vaccination, and bolster pandemic preparedness. Globally, vaccination coverage of health workers varied from 10 % to 88 %. Understanding health workers' knowledge and acceptance of the influenza vaccine, particularly among physicians, is crucial for the fine-tuning and continued success of influenza vaccination campaigns. We conducted a cross-sectional survey of 472 health workers in Abidjan, Côte d'Ivoire, to inform subsequent subnational and national introductions of influenza vaccine and subsequent campaigns targeting health workers in 2019 (14302), 2020 (14872), and 2021 (24473). Using a purposive sample of university hospitals, general hospitals, rural, and urban health facilities, we interviewed a convenience sample of health workers aged 18 years and older. Physicians had the lowest intention to receive the influenza vaccine (58 %), while nurses (78 %) and midwives (76 %) were the most willing. Across all occupations, intention to receive vaccination increased if the vaccine was offered for free or if recommended by the Ministry of Health. 76 % of respondents believed that the influenza vaccine could prevent illness in health workers. Communication strategies, including about the benefits of influenza vaccination, could raise awareness and acceptance among health workers prior to vaccination campaigns. Influenza vaccination coverage rates between 2019 and 2021 were on par with rates of intention to receive vaccination in the 2018 survey; in 2019, 2020, and 2021, coverage among physicians was 73 %, 73 %, and 52 % and coverage among nurses and midwives was 86 %, 86 %, and 74 % respectively. Improving health workers' knowledge and acceptance of the influenza vaccine, particularly among physicians, is crucial for the continued success of influenza vaccination campaigns.

BACKGROUND: Despite the substantial global impact of influenza, there are limited economic data to guide influenza vaccination programs investments in middle-income countries. We measured the costs of influenza and the costs of an influenza vaccination program in Armenia, using a societal perspective. METHODS: During December 2022 through March 2023, retrospective cost data were collected from case-patients and healthcare providers through structured questionnaires at 15 healthcare facilities selected through stratified sampling. Medical costs included medications, laboratory costs, laboratory and diagnostic tests, and routine health care service costs and direct and indirect societal costs were included. Vaccination program costs from the 2021-2022 influenza season were identified using accounting records and categorized as: planning, distribution, training, social mobilization and outreach, supervision and monitoring, procurement, and national- and facility-level administration and storage. RESULTS: The mean costs per episode for SARI and ILI case-patients were $US 823.6 and $US 616.57, respectively. Healthcare service costs were the largest direct expenses for ILI and SARI case-patients. Total costs of the 2021-2022 influenza vaccination program to the government were $US 4,353,738, with the largest costs associated with national- and facility-level administration and storage (30% and 65% respectively). The total cost per dose administered was $US 25.61 ($US 7.73 per dose for procurement and $US 17.88 for the marginal administration cost per dose). CONCLUSIONS: These data on the costs of seasonal influenza prevention programs and the societal costs of influenza illness in Armenia may inform national vaccine policy decisions in Armenia and may be useful for other middle-income countries. Influenza vaccines, like other vaccine programs, are recognized as substantially contributing to the reduction disease burden and associated mortality and further driving economic growth. However, a formal cost-effectiveness analysis should be performed once burden of disease data are available.

Increasing opportunities for prevention of infectious diseases by new, effective vaccines and the expansion of global immunization programs across the life course highlight the importance and value of evidence-informed decision-making (EIDM) by National Immunization Technical Advisory Groups (NITAGs). The U.S. Centers for Disease Control and Prevention (CDC) and Task Force for Global Health (TFGH) have developed and made available new tools to support NITAGs in EIDM. These include a toolkit for conducting facilitated training of NITAGs, Secretariats, or work groups on the use of the Evidence to Recommendations (EtR) approach to advise Ministries of Health (MoH) on specific vaccine policies, and an eLearning module on the EtR approach for NITAG members, Secretariat and others. The CDC and TFGH have also supported final development and implementation of the NITAG Maturity Assessment Tool (NMAT) for assessing maturity of NITAG capabilities in seven functional domains. The EtR toolkit and eLearning have been widely promoted in collaboration with the World Health Organization (WHO) Headquarters and Regional Offices through workshops engaging over 30 countries to date, and the NMAT assessment tool used in most countries in 3 WHO regions (Americas, Eastern Mediterranean, African). Important lessons have been learned regarding planning and conducting trainings for multiple countries and additional ways to support countries in applying the EtR approach to complete vaccine recommendations. Priorities for future work include the need to evaluate the impact of EtR training and NMAT assessments, working with partners to expand and adapt these tools for wider use, synergizing with other approaches for NITAG strengthening, and developing the best approaches to empower NITAGs to use the EtR approach.

BACKGROUND: Historically, 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 that could hinder global implementation of influenza vaccination programs. METHODS AND FINDINGS: We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus in January 2022 and October 2023 using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2022. Studies were eligible if they (1) presented original, peer-reviewed findings on cost of illness, cost of vaccination program, or cost-effectiveness of vaccination for seasonal influenza; and (2) included data for at least 1 low- or middle-income country. We abstracted general study characteristics and data specific to each of the 3 study types. Of 54 included studies, 26 presented data on cost-effectiveness, 24 on cost-of-illness, and 5 on program costs. Represented countries were classified as upper-middle income (UMIC; n = 12), 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 = 17), and persons with chronic medical conditions (n = 12); fewer studies evaluated pregnant persons (n = 9), healthcare workers (n = 5), and persons in congregate living settings (n = 1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest national economic burden, as a percent of gross domestic product and national health expenditure, was reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (88%) interpreted at least 1 scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Key limitations of this work included (1) heterogeneity across included studies; (2) restrictiveness of the inclusion criteria used; and (3) potential for missed influenza burden from use of sentinel surveillance systems. CONCLUSIONS: The 54 studies identified in this review suggest an increased momentum to generate economic evidence about influenza illness and vaccination from low- and middle-income countries during 2012 to 2022. However, given that we observed substantial heterogeneity, continued evaluation of the economic burden of influenza illness and costs/cost-effectiveness of influenza vaccination, particularly in LICs and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed. Use of standardized methodology could facilitate pooling across settings and knowledge sharing to strengthen global influenza vaccination programs.

BACKGROUND: During November 2019-October 2021, a pediatric influenza vaccination demonstration project was conducted in four sub-counties in Kenya. The demonstration piloted two different delivery strategies: year-round vaccination and a four-month vaccination campaign. Our objective was to compare the costs of both delivery strategies. METHODS: Cost data were collected using standardized questionnaires and extracted from government and project accounting records. We reported total costs and costs per vaccine dose administered by delivery strategy from the Kenyan government perspective in 2021 US$. Costs were separated into financial costs (monetary expenditures) and economic costs (financial costs plus the value of existing resources). We also separated costs by administrative level (national, regional, county, sub-county, and health facility) and program activity (advocacy and social mobilization; training; distribution, storage, and waste management; service delivery; monitoring; and supervision). RESULTS: The total estimated cost of the pediatric influenza demonstration project was US$ 225,269 (financial) and US$ 326,691 (economic) for the year-round delivery strategy (30,397 vaccine doses administered), compared with US$ 214,753 (financial) and US$ 242,385 (economic) for the campaign strategy (25,404 doses administered). Vaccine purchase represented the largest proportion of costs for both strategies. Excluding vaccine purchase, the cost per dose administered was US$ 1.58 (financial) and US$ 5.84 (economic) for the year-round strategy and US$ 2.89 (financial) and US$ 4.56 (economic) for the campaign strategy. CONCLUSIONS: The financial cost per dose was 83% higher for the campaign strategy than the year-round strategy due to larger expenditures for advocacy and social mobilization, training, and hiring of surge staff for service delivery. However, the economic cost per dose was more comparable for both strategies (year-round 22% higher than campaign), balanced by higher costs of operating equipment and monitoring activities for the year-round strategy. These delivery cost data provide real-world evidence to inform pediatric influenza vaccine introduction in Kenya.

INTRODUCTION: In 2016, the Kenya National Immunization Technical Advisory Group requested additional programmatic and cost effectiveness data to inform the choice of strategy for a national influenza vaccination program among children aged 6-23 months of age. In response, we conducted an influenza vaccine demonstration project to compare the performance of a year-round versus campaign-mode vaccination strategy. Findings from this demonstration project will help identify essential learning lessons for a national program. METHODS: We compared two vaccine delivery strategies: (i) a year-round vaccination strategy where influenza vaccines were administered throughout the year at health facilities. This strategy was implemented in Njoro sub-county in Nakuru (November 2019 to October 2021) and Jomvu sub-county in Mombasa (December 2019 to October 2021), (ii) a campaign-mode vaccination strategy where vaccines were available at health facilities over four months. This strategy was implemented in Nakuru North sub-county in Nakuru (June to September 2021) and Likoni sub-county in Mombasa (July to October 2021). We assessed differences in coverage, dropout rates, vaccine wastage, and operational needs. RESULTS: We observed similar performance between strategies in coverage of the first dose of influenza vaccine (year-round strategy 59.7 %, campaign strategy 63.2 %). The coverage obtained in the year-round sub-counties was similar (Njoro 57.4 %; Jomvu 63.1 %); however, more marked differences between campaign sub-counties were observed (Nakuru North 73.4 %; Likoni 55.2 %). The campaign-mode strategy exceeded the cold chain capacity of participating health facilities, requiring thrice monthly instead of once monthly deliveries, and was associated with a two-fold increase in workload compared to the year-round strategy (168 vaccines administered per day in the campaign strategy versus 83 vaccines administered per day in the year-round strategy). CONCLUSION: Although both strategies had similar coverage levels, the campaign-mode strategy was associated with considerable operational needs that could significantly impact the immunization program.

This report summarizes recommendations approved on February 21, 2013, by the Advisory Committee on Immunization Practices (ACIP) for the use of influenza vaccines. An expanded 2013 ACIP influenza vaccination recommendation statement is scheduled to be published in MMWR Recommendations and Reports before the start of the 2013-14 influenza season. Providers should consult the expanded 2013 ACIP influenza vaccination statement for complete and updated information.

This report updates the 2012 recommendations by CDC's Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccines for the prevention and control of seasonal influenza (CDC. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2012;61:613-8). Routine annual influenza vaccination is recommended for all persons aged ≥ 6 months. For the 2013-14 influenza season, it is expected that trivalent live attenuated influenza vaccine (LAIV3) will be replaced by a quadrivalent LAIV formulation (LAIV4). Inactivated influenza vaccines (IIVs) will be available in both trivalent (IIV3) and quadrivalent (IIV4) formulations. Vaccine virus strains included in the 2013-14 U.S. trivalent influenza vaccines will be an A/California/7/2009 (H1N1)-like virus, an H3N2 virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011, and a B/Massachusetts/2/2012-like virus. Quadrivalent vaccines will include an additional influenza B virus strain, a B/Brisbane/60/2008-like virus, intended to ensure that both influenza B virus antigenic lineages (Victoria and Yamagata) are included in the vaccine. This report describes recently approved vaccines, including LAIV4, IIV4, trivalent cell culture-based inactivated influenza vaccine (ccIIV3), and trivalent recombinant influenza vaccine (RIV3). No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one product is otherwise appropriate. This information is intended for vaccination providers, immunization program personnel, and public health personnel. These recommendations and other information are available at CDC's influenza website (http://www.cdc.gov/flu); any updates also will be found at this website. Vaccination and health-care providers should check the CDC influenza website periodically for additional information.

In 2010, the Advisory Committee on Immunization Practices (ACIP) first recommended annual influenza vaccination for all persons aged ≥6 months in the United States (1). Annual influenza vaccination of all persons aged ≥6 months continues to be recommended. This document 1) describes influenza vaccine virus strains included in the U.S. seasonal influenza vaccine for 2012-13; 2) provides guidance for the use of influenza vaccines during the 2012-13 season, including an updated vaccination schedule for children aged 6 months through 8 years and a description of available vaccine products and indications; 3) discusses febrile seizures associated with administration of influenza and 13-valent pneumococcal conjugate (PCV-13) vaccines; 4) provides vaccination recommendations for persons with a history of egg allergy; and 5) discusses the development of quadrivalent influenza vaccines for use in future influenza seasons. Information regarding issues related to influenza vaccination that are not addressed in this update is available in CDC's Prevention and Control of Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2010 and associated updates (1,2).

This document provides updated guidance for the use of influenza vaccines in the United States for the 2011–12 influenza season. In 2010, the Advisory Committee on Immunization Practices (ACIP) first recommended annual influenza vaccination for all persons aged ≥6 months in the United States (1,2). Vaccination of all persons aged ≥6 months continues to be recommended. Information is presented in this report regarding vaccine strains for the 2011–12 influenza season, the vaccination schedule for children aged 6 months through 8 years, and considerations regarding vaccination of persons with egg allergy. Availability of a new Food and Drug Administration (FDA)-approved intradermally administered influenza vaccine formulation for adults aged 18 through 64 years is reported. For issues related to influenza vaccination that are not addressed in this update, refer to the 2010 ACIP statement on prevention and control of influenza with vaccines and associated updates (1,2). | | Methodology for the formulation of the ACIP annual influenza statement has been described previously (1). The ACIP Influenza Work Group meets every 2–4 weeks throughout the year. Work Group membership includes several voting members of the ACIP, as well as representatives from ACIP Liaison Organizations. Meetings are held by teleconference and include discussion of influenza-related issues, such as vaccine effectiveness and safety, coverage in groups recommended for vaccination, feasibility, cost-effectiveness, and anticipated vaccine supply. Presentations are requested from invited experts, and published and unpublished data are discussed. CDC's Influenza Division provides influenza surveillance and antiviral resistance data, and the Immunization Safety Office and Immunization Services Division provide information on vaccine safety and distribution and coverage, respectively.

This document provides updated guidance for the use of influenza vaccines in the United States for the 2011-12 influenza season. In 2010, the Advisory Committee on Immunization Practices (ACIP) first recommended annual influenza vaccination for all persons aged ≥6 months in the United States. Vaccination of all persons aged ≥6 months continues to be recommended. Information is presented in this report regarding vaccine strains for the 2011-12 influenza season, the vaccination schedule for children aged 6 months through 8 years, and considerations regarding vaccination of persons with egg allergy. Availability of a new Food and Drug Administration (FDA)-approved intradermally administered influenza vaccine formulation for adults aged 18 through 64 years is reported. For issues related to influenza vaccination that are not addressed in this update, refer to the 2010 ACIP statement on prevention and control of influenza with vaccines and associated updates.

This report updates previous recommendations by CDC's Advisory Committee on Immunization Practices (ACIP) regarding the use of antiviral agents for the prevention and treatment of influenza (CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2008;57[No. RR-7]).This report contains information on treatment and chemoprophylaxis of influenza virus infection and provides a summary of the effectiveness and safety of antiviral treatment medications. Highlights include recommendations for use of 1) early antiviral treatment of suspected or confirmed influenza among persons with severe influenza (e.g., those who have severe, complicated, or progressive illness or who require hospitalization); 2) early antiviral treatment of suspected or confirmed influenza among persons at higher risk for influenza complications; and 3) either oseltamivir or zanamivir for persons with influenza caused by 2009 H1N1 virus, influenza A (H3N2) virus, or influenza B virus or when the influenza virus type or influenza A virus subtype is unknown; 4) antiviral medications among children aged <1 year; 5) local influenza testing and influenza surveillance data, when available, to help guide treatment decisions; and 6) consideration of antiviral treatment for outpatients with confirmed or suspected influenza who do not have known risk factors for severe illness, if treatment can be initiated within 48 hours of illness onset. Additional information is available from CDC's influenza website at http://www.cdc.gov/flu, including any updates or supplements to these recommendations that might be required during the 2010-11 influenza season. Health-care providers should be alert to announcements of recommendation updates and should check the CDC influenza website periodically for additional information. Recommendations related to the use of vaccines for the prevention of influenza during the 2010-11 influenza season have been published previously (CDC. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices [ACIP], 2010. MMWR 2010;59[No. RR-8]).

This report updates the 2009 recommendations by CDC's Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccine for the prevention and control of influenza (CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2009;58[No. RR-8] and CDC. Use of influenza A (H1N1) 2009 monovalent vaccine---recommendations of the Advisory Committee on Immunization Practices [ACIP], 2009. MMWR 2009;58:[No. RR-10]). The 2010 influenza recommendations include new and updated information. Highlights of the 2010 recommendations include 1) a recommendation that annual vaccination be administered to all persons aged >or=6 months for the 2010-11 influenza season; 2) a recommendation that children aged 6 months--8 years whose vaccination status is unknown or who have never received seasonal influenza vaccine before (or who received seasonal vaccine for the first time in 2009-10 but received only 1 dose in their first year of vaccination) as well as children who did not receive at least 1 dose of an influenza A (H1N1) 2009 monovalent vaccine regardless of previous influenza vaccine history should receive 2 doses of a 2010-11 seasonal influenza vaccine (minimum interval: 4 weeks) during the 2010--11 season; 3) a recommendation that vaccines containing the 2010-11 trivalent vaccine virus strains A/California/7/2009 (H1N1)-like (the same strain as was used for 2009 H1N1 monovalent vaccines), A/Perth/16/2009 (H3N2)-like, and B/Brisbane/60/2008-like antigens be used; 4) information about Fluzone High-Dose, a newly approved vaccine for persons aged >or=65 years; and 5) information about other standard-dose newly approved influenza vaccines and previously approved vaccines with expanded age indications. Vaccination efforts should begin as soon as the 2010-11 seasonal influenza vaccine is available and continue through the influenza season. These recommendations also include a summary of safety data for U.S.-licensed influenza vaccines. These recommendations and other information are available at CDC's influenza website (http://www.cdc.gov/flu); any updates or supplements that might be required during the 2010-11 influenza season also will be available at this website. Recommendations for influenza diagnosis and antiviral use will be published before the start of the 2010-11 influenza season. Vaccination and health-care providers should be alert to announcements of recommendation updates and should check the CDC influenza website periodically for additional information.

This report updates the 2008 recommendations by CDC's Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccine for the prevention and control of seasonal influenza (CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2008;57[No. RR-7]). Information on vaccination issues related to the recently identified novel influenza A H1N1 virus will be published later in 2009. The 2009 seasonal influenza recommendations include new and updated information. Highlights of the 2009 recommendations include 1) a recommendation that annual vaccination be administered to all children aged 6 months-18 years for the 2009-10 influenza season; 2) a recommendation that vaccines containing the 2009-10 trivalent vaccine virus strains A/Brisbane/59/2007 (H1N1)-like, A/Brisbane/10/2007 (H3N2)-like, and B/Brisbane/60/2008-like antigens be used; and 3) a notice that recommendations for influenza diagnosis and antiviral use will be published before the start of the 2009-10 influenza season. Vaccination efforts should begin as soon as vaccine is available and continue through the influenza season. Approximately 83% of the United States population is specifically recommended for annual vaccination against seasonal influenza; however, <40% of the U.S. population received the 2008-09 influenza vaccine. These recommendations also include a summary of safety data for U.S. licensed influenza vaccines. These recommendations and other information are available at CDC's influenza website (http://www.cdc.gov/flu); any updates or supplements that might be required during the 2009-10 influenza season also can be found at this website. Vaccination and health-care providers should be alert to announcements of recommendation updates and should check the CDC influenza website periodically for additional information.

Importance: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a prevalent disorder known to be notoriously difficult to treat. Objective: The aim of the study was to determine intravesical instillation patterns among women receiving treatment for IC/BPS. Study Design: This was a retrospective claims-based analysis using the Veterans Affairs Informatics and Computing Infrastructure. Females with an International Classification of Diseases, Ninth Revision, diagnosis of IC/BPS (595.1) were sampled randomly. Patients were considered to have IC/BPS if they had 2 visits with bladder pain in the absence of a positive urine culture 6 weeks or more apart or a history of bladder pain with another visit for bladder pain. Dates of intravesical instillations were extracted. A 'course' of instillations was defined as 1 or more instillations made with less than 21 days between visits. Results: We identified 641 women with a confirmed diagnosis of IC/BPS, 78 of whom underwent a total of 344 intravesical instillations. On average, each woman had 1.5 ± 0.8 courses between October 2004 and July 2016. Each course was an average of 3.1 ± 2.6 instillations. Fifty-five percent of courses consisted of 1 instillation. Only 22% of courses had 6 or more instillations, the number typically recommended to achieve clinical response. Each instillation within a course was an average of 9.4 ± 4.0 days apart. Most instillations (77%) involved a cocktail of 2 or more drugs. Conclusions: In our cohort, few women with IC/BPS received a recommended treatment course of 6 weekly instillations, with most receiving only 1 per course. Future studies are needed to determine whether instillation courses were altered from the guidelines due to health care provider practice patterns, early improvement, or poor tolerance of instillations. © 2023 Authors. All rights reserved.

Introduction: Historically, 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. Method(s): We 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. Result(s): Of 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. Conclusion(s): Continued 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. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license.

This article summarizes what is currently known about the 2019 novel coronavirus and offers interim guidance.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

BACKGROUND: Using country-specific surveillance data to describe influenza epidemic activity could inform decisions on the timing of influenza vaccination. We analysed surveillance data from African countries to characterise the timing of seasonal influenza epidemics to inform national vaccination strategies. METHODS: We used publicly available sentinel data from African countries reporting to the WHO Global Influenza Surveillance and Response FluNet platform that had 3-10 years of data collected during 2010-19. We calculated a 3-week moving proportion of samples positive for influenza virus and assessed epidemic timing using an aggregate average method. The start and end of each epidemic were defined as the first week when the proportion of positive samples exceeded or went below the annual mean, respectively, for at least 3 consecutive weeks. We categorised countries into five epidemic patterns: northern hemisphere-dominant, with epidemics occurring in October-March; southern hemisphere-dominant, with epidemics occurring in April-September; primarily northern hemisphere with some epidemic activity in southern hemisphere months; primarily southern hemisphere with some epidemic activity in northern hemisphere months; and year-round influenza transmission without a discernible northern hemisphere or southern hemisphere predominance (no clear pattern). FINDINGS: Of the 34 countries reporting data to FluNet, 25 had at least 3 years of data, representing 46% of the countries in Africa and 89% of Africa's population. Study countries reported RT-PCR respiratory virus results for a total of 503 609 specimens (median 12 971 [IQR 9607-20 960] per country-year), of which 74 001 (15%; median 2078 [IQR 1087-3008] per country-year) were positive for influenza viruses. 248 epidemics occurred across 236 country-years of data (median 10 [range 7-10] per country). Six (24%) countries had a northern hemisphere pattern (Algeria, Burkina Faso, Egypt, Morocco, Niger, and Tunisia). Eight (32%) had a primarily northern hemisphere pattern with some southern hemisphere epidemics (Cameroon, Ethiopia, Mali, Mozambique, Nigeria, Senegal, Tanzania, and Togo). Three (12%) had a primarily southern hemisphere pattern with some northern hemisphere epidemics (Ghana, Kenya, and Uganda). Three (12%) had a southern hemisphere pattern (Central African Republic, South Africa, and Zambia). Five (20%) had no clear pattern (Côte d'Ivoire, DR Congo, Madagascar, Mauritius, and Rwanda). INTERPRETATION: Most countries had identifiable influenza epidemic periods that could be used to inform authorities of non-seasonal and seasonal influenza activity, guide vaccine timing, and promote timely interventions. FUNDING: None. TRANSLATIONS: For the Berber, Luganda, Xhosa, Chewa, Yoruba, Igbo, Hausa and Afan Oromo translations of the abstract see Supplementary Materials section.

A network of global respiratory disease surveillance systems and partnerships has been built over decades as a direct response to the persistent threat of seasonal, zoonotic, and pandemic influenza. These efforts have been spearheaded by the World Health Organization, country ministries of health, the US Centers for Disease Control and Prevention, nongovernmental organizations, academic groups, and others. During the COVID-19 pandemic, the US Centers for Disease Control and Prevention worked closely with ministries of health in partner countries and the World Health Organization to leverage influenza surveillance systems and programs to respond to SARS-CoV-2 transmission. Countries used existing surveillance systems for severe acute respiratory infection and influenza-like illness, respiratory virus laboratory resources, pandemic influenza preparedness plans, and ongoing population-based influenza studies to track, study, and respond to SARS-CoV-2 infections. The incorporation of COVID-19 surveillance into existing influenza sentinel surveillance systems can support continued global surveillance for respiratory viruses with pandemic potential.

The US Centers for Disease Control and Prevention (CDC) supports international partners in introducing vaccines, including those against SARS-CoV-2 virus. CDC contributes to the development of global technical tools, guidance, and policy for COVID-19 vaccination and has established its COVID-19 International Vaccine Implementation and Evaluation (CIVIE) program. CIVIE supports ministries of health and their partner organizations in developing or strengthening their national capacities for the planning, implementation, and evaluation of COVID-19 vaccination programs. CIVIE's 7 priority areas for country-specific technical assistance are vaccine policy development, program planning, vaccine confidence and demand, data management and use, workforce development, vaccine safety, and evaluation. We discuss CDC's work on global COVID-19 vaccine implementation, including priorities, challenges, opportunities, and applicable lessons learned from prior experiences with Ebola, influenza, and meningococcal serogroup A conjugate vaccine introductions.

BACKGROUND: Global estimates showed an estimate of up to 650,000 seasonal influenza-associated respiratory deaths annually. However, the mortality rate of seasonal influenza is unknown for most countries in the WHO Eastern Mediterranean Region, including Iran. We aimed to estimate the excess mortality attributable to seasonal influenza in Kerman province, southeast Iran for the influenza seasons 2006/2007-2011/2012. METHODS: We applied a Serfling model to the weekly total pneumonia and influenza (PI) mortality rate during winter to define the epidemic periods and to the weekly age-specific PI, respiratory, circulatory, and all-cause deaths during non-epidemic periods to estimate baseline mortality. The excess mortality was calculated as the difference between observed and predicted mortality. Country estimates were obtained by multiplying the estimated annual excess death rates by the populations of Iran. RESULTS: We estimated an annual average excess of 40 PI, 100 respiratory, 94 circulatory, and 306 all-cause deaths attributable to seasonal influenza in Kerman; corresponding to annual rates of 1.4 (95% confidence interval [CI] 1.1-1.8) PI, 3.6 (95% CI 2.6-4.8) respiratory, 3.4 (95% CI 2.1-5.2) circulatory, and 11.0 (95% CI 7.3-15.6) all-cause deaths per 100,000 population. Adults ≥75 years accounted for 56% and 53% of all excess respiratory and circulatory deaths, respectively. At country level, we would expect an annual of 1119 PI to 8792 all-cause deaths attributable to seasonal influenza. CONCLUSIONS: Our findings help to define the mortality burden of seasonal influenza, most of which affects adults aged ≥75 years. This study supports influenza prevention and vaccination programs in older adults.

BACKGROUND: The aim of this project was to develop a road map to support countries in Eastern Mediterranean Region in developing and implementing evidence-based seasonal influenza vaccination policy, strengthen influenza vaccination delivery program and address vaccine misperceptions and hesitancy. METHODS: The road map was developed through consultative meetings with countries' focal points, review of relevant literature and policy documents and analysis of WHO/UNICEF Joint Reporting Form on immunization ((JRF 2015-2020) data. Countries were categorised into three groups, based on the existence of influenza vaccination policy and national regulatory authority, availability of influenza vaccine in the country and number of influenza vaccine doses distributed/ 1000 population. The final road map was shared with representatives of all countries in Eastern Mediterranean Region and other stakeholders during a meeting in September 2021. RESULT: The goal for next 5years is to increase access to and use of utilization of seasonal influenza vaccine in Eastern Mediterranean Region to reduce influenza-associated morbidity and mortality among priority groups for vaccination. Countries in the Eastern Mediterranean Region are at different stages of implementation of the influenza vaccination program, so activities are planned under four strategic priority areas based on current situations in countries. The consultative body recommended that some countries should establish a new seasonal influenza vaccination programme and ensure the availability of vaccines, while other countries need to reduce vaccine hesitancy and enhance current seasonal influenza vaccination coverage, particularly in all high-risk groups. Countries are also encouraged to leverage COVID-19 adult vaccination programs to improve seasonal influenza vaccine uptake. CONCLUSION: This road map was developed through a consultative process to scale up the uptake and utilization of influenza vaccine in all countries of Eastern Mediterranean Region. The road map proposes activities that should be adopted in the local context to develop/ update national policies and programs.

IMPORTANCE: Interstitial cystitis/bladder pain syndrome (IC/BPS) is an immense burden to both patients and the American healthcare system; it is notoriously difficult to diagnose. Prevalence estimates vary widely (150-fold range in women and >500-fold range in men). OBJECTIVES: We aimed to create accurate national IC/BPS prevalence estimates by employing a novel methodology combining a national population-based dataset with individual chart abstraction. STUDY DESIGN: In this epidemiological survey, all living patients, with ≥2 clinic visits from 2016 to 2018 in the Veterans Health Administration, with an ICD-9/10 code for IC/BPS (n = 9,503) or similar conditions that may represent undiagnosed IC/BPS (n = 124,331), were identified (other were controls n = 5,069,695). A detailed chart review of random gender-balanced samples confirmed the true presence of IC/PBS, which were then age- and gender-matched to the general US population. RESULTS: Of the 5,203,529 patients identified, IC/BPS was confirmed in 541 of 1,647 sampled charts with an IC/BPS ICD code, 10 of 382 charts with an ICD-like code, and 3 of 916 controls. After age- and gender-matching to the general US population, this translated to national prevalence estimates of 0.87% (95% CI: 0.32, 1.42), with female and male prevalence of 1.08% (95% CI: 0.03, 2.13) and 0.66% (95% CI: 0.44, 0.87), respectively. CONCLUSIONS: We estimate the prevalence of IC/BPS to be 0.87%, which is lower than prior estimates based on survey data, but higher than prior estimates based on administrative data. These potentially represent the most accurate estimates to date, given the broader and more heterogeneous population studied and our novel methodology of combining in-depth chart abstraction with administrative data.

OBJECTIVE: To assess the stability of improvements in global respiratory virus surveillance in countries supported by the United States Centers for Disease Control and Prevention (CDC) after reductions in CDC funding and with the stress of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We assessed whether national influenza surveillance systems of CDC-funded countries: (i) continued to analyse as many specimens between 2013 and 2021; (ii) participated in activities of the World Health Organization's (WHO) Global Influenza Surveillance and Response System; (iii) tested enough specimens to detect rare events or signals of unusual activity; and (iv) demonstrated stability before and during the COVID-19 pandemic. We used CDC budget records and data from the WHO Global Influenza Surveillance and Response System. FINDINGS: While CDC reduced per-country influenza funding by about 75% over 10 years, the number of specimens tested annually remained stable (mean 2261). Reporting varied substantially by country and transmission zone. Countries funded by CDC accounted for 71% (range 61-75%) of specimens included in WHO consultations on the composition of influenza virus vaccines. In 2019, only eight of the 17 transmission zones sent enough specimens to WHO collaborating centres before the vaccine composition meeting to reliably identify antigenic variants. CONCLUSION: Great progress has been made in the global understanding of influenza trends and seasonality. To optimize surveillance to identify atypical influenza viruses, and to integrate molecular testing, sequencing and reporting of severe acute respiratory syndrome coronavirus 2 into existing systems, funding must continue to support these efforts.

OBJECTIVE: To describe prescription prevalence of oral bladder pain medications among women with interstitial cystitis/bladder pain syndrome (IC/BPS) and to compare with current treatment guidelines. METHODS: We sampled female patients with an ICD-9/10 diagnosis of IC/BPS (595.1/N30.10) by querying active users of the Veterans Health Administration. Medical records were reviewed to determine whether patients met IC/BPS diagnostic criteria. A cohort of women with other pelvic pain disorders was identified. Prescription prevalence of typical non-narcotic oral bladder pain medications was compared between the two groups and healthy controls. Prescription prevalence was also compared before and after the diagnosis of IC/BPS was made using Poisson regression. RESULTS: There were 641 women who met criteria for IC/BPS and 197 women with "Other pelvic pain" disorders. Women with IC/BPS were prescribed a pain medication more often than those with "Other pelvic pain" (77% vs. 59%, p<0.0001). Of the women with IC/BPS, 44% tried three or more pain medications. Of women with a diagnosis of IC/BPS, only 67% were prescribed an American Urological Association-recommended medication. Prescription prevalence increased after diagnosis for both pentosan polysulfate (10%-29%, p<0.0001) and hydroxyzine (17%-40%, p<0.0001), but not for amitriptyline or cimetidine. Amitriptyline was prescribed to 223 women with IC/BPS, only 125 of which (56%) had a documented history of depression. CONCLUSIONS: Many women with IC/BPS required multiple bladder prescriptions, highlighting the difficulty in finding an effective treatment for IC/BPS. Pentosan polysulfate and hydroxyzine were preferred IC/BPS medications. Our next step will be to analyze treatment patterns in those patients who did not receive medications.