Seasonal influenza vaccination policies in the 194 WHO Member States: The evolution of global influenza pandemic preparedness and the challenge of sustaining equitable vaccine access.

INTRODUCTION: As of 2018, 118 of 194 WHO Member States reported the presence of an influenza vaccination policy. Although influenza vaccination policies do not guarantee equitable access or ensure vaccination coverage, they are critical to establishing a coordinated influenza vaccination program, which can reduce morbidity and mortality associated with yearly influenza, especially in high-risk groups. Established programs can also provide a good foundation for pandemic preparedness and response. METHODS: We utilized EXCEL and STATA to evaluate changes to national seasonal influenza vaccination policies reported on the WHO/UNICEF Joint Reporting Forms on Immunization (JRF) in 2014 and 2018. To characterize countries with or without policies, we incorporated external data on World Bank income groupings, WHO regions, and immunization system strength (using 3 proxy indicators). RESULTS: From 2014 to 2018 there was a small net increase in national seasonal influenza vaccination policies from 114 (59%) to 118 (61%). There was an increase in policies targeting high-risk groups from 34 in 2014 (34 /114 policies, 29%) to 56 (56/118 policies, 47%) in 2018. Policies were consistently more frequent in high-income countries, in WHO Regions of the Americas (89% of countries) and Europe (89%), and in countries satisfying all three immunization system strength indicators. Low and low-middle income countries, representing 40% of the worlds' population, accounted for 52/61 (85%) of countries with no evidence of a policy in either year. CONCLUSION: Our results demonstrate that national influenza vaccination policies vary significantly by region, income, and immunization system strength, and are less common in lower-income countries. Barriers to establishing and maintaining policies should be further examined as part of international efforts to expand influenza vaccination policies globally. Next generation influenza vaccine development should work to address barriers to influenza vaccination policy adoption, such as cost, logistics for adult vaccination, country priorities, need for yearly vaccination, and variations in seasonality.

The faces of influenza vaccine recommendation: A Literature review of the determinants and barriers to health providers' recommendation of influenza vaccine in pregnancy.

INTRODUCTION: WHO recommends influenza vaccination for pregnant women and health providers (HPs), yet global uptake for both is persistently low. Research suggests that HPs greatly influence uptake of influenza vaccine in pregnant women. Our review studies HPs' recommendation of influenza vaccine to pregnant women, determinants and barriers to recommendation, and the role that HPs may play in global influenza vaccine coverage. METHODS: We undertook a comprehensive global review of literature relating to HPs' recommendation of seasonal influenza vaccines to pregnant women and the determinants and barriers to recommendation and how this may vary by country and context. We evaluated data from each study including frequency of HP recommendation, vaccine coverage, determinants and barriers to recommendation, and the odds of recommending. We tracked the frequency of determinants and barriers to recommendation in heat maps and organized data by world regions and income classifications. RESULTS: From 32 studies in 15 countries, we identified 68 determinants or barriers to HPs' recommendation. Recommendation rates were highest (77%) in the Americas and lowest in South East Asia (18%). A HP's own influenza vaccine status was a main determinant of recommendation in multiple country contexts and from different provider types. Financial barriers to recommendation were present in higher-income countries and policy-related barriers were highlighted in lower-income countries. HP perceptions of safety, efficacy, and the utility of vaccine were the most frequently cited barriers, relevant in almost every context. CONCLUSIONS: HP recommendation is important to influenza vaccine implementation in pregnant women. A HP's own status is an important recommendation determinant in multiple contexts. Vaccine program implementation plans should consider the impact of HPs' knowledge, awareness and vaccine confidence on their own uptake and recommendation practices, as well as on the uptake among pregnant women. Addressing safety and efficacy concerns is relevant in all contexts for HPs and pregnant women.

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

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

A rapid evidence appraisal of influenza vaccination in health workers: An important policy in an area of imperfect evidence.

INTRODUCTION: The World Health Organization recommends vaccination of health workers (HWs) against influenza, but low uptake is intransigent.We conducted a Rapid Evidence Appraisal on: the risk of influenza in HWs, transmission risk from HWs to patients, the benefit of HW vaccination, and strategies for improving uptake. We aimed to capture a 'whole-of-system' perspective to consider possible benefits for HWs, employers and patients. METHODS: We executed a comprehensive search of the available literature published from 2006 to 2018 in the English language. We developed search terms for seven separate questions following the PICO framework (population, intervention, comparators, outcomes) and queried nine databases. RESULTS: Of 3784 publications identified, 52 met inclusion criteria. Seven addressed HW influenza risk, of which four found increased risk; 15 addressed influenza vaccine benefit to HWs or their employers, of which 10 found benefit; 11 addressed influenza transmission from HWs to patients, of which 6 found evidence for transmission; 12 unique studies addressed whether vaccinating HWs produced patient benefit, of which 9 concluded benefits accrued. Regarding the number of HWs needed to vaccinate (NNV) to deliver patient benefit, NNV estimates ranged from 3 to 36,000 but were in significant disagreement. Fourteen studies provided insights on strategies to improve uptake; the strongest evidence was for mandatory vaccination. CONCLUSIONS: The evidence on most questions related to influenza vaccination in HWs is mixed and often of low-quality. Substantial heterogeneity exists in terms of study designs and settings, making comparison between studies difficult. Notwithstanding these limitations, a majority of studies suggests that influenza vaccination benefit HWs and their employers; and HWs are implicated in transmission events. The effects of vaccinating HWs on patient morbidity and mortality may include reductions in all-cause mortality and influenza-like illness (ILI). Taken together, the evidence suggests that HW vaccination is an important policy for HWs themselves, their employers, and their patients.

Possible explanations for why some countries were harder hit by the pandemic influenza virus in 2009 - a global mortality impact modeling study.

BACKGROUND: A global pandemic mortality study found prominent regional mortality variations in 2009 for Influenza A(H1N1)pdm09. Our study attempts to identify factors that explain why the pandemic mortality burden was high in some countries and low in others. METHODS: As a starting point, we identified possible risk factors worth investigating for Influenza A(H1N1)pdm09 mortality through a targeted literature search. We then used a modeling procedure (data simulations and regression models) to identify factors that could explain differences in respiratory mortality due to Influenza A(H1N1)pdm09. We ran sixteen models to produce robust results and draw conclusions. In order to assess the role of each factor in explaining differences in excess pandemic mortality, we calculated the reduction in between country variance, which can be viewed as an effect-size for each factor. RESULTS: The literature search identified 124 publications and 48 possible risk factors, of which we were able to identify 27 factors with appropriate global datasets. The modelling procedure indicated that age structure (explaining 40% of the mean between country variance), latitude (8%), influenza A and B viruses circulating during the pandemic (3-8%), influenza A and B viruses circulating during the preceding influenza season (2-6%), air pollution (pm10; 4%) and the prevalence of other infections (HIV and TB) (4-6%) were factors that explained differences in mortality around the world. Healthcare expenditure, levels of obesity, the distribution of antivirals, and air travel did not explain global pandemic mortality differences. CONCLUSIONS: Our study found that countries with a large proportion of young persons had higher pandemic mortality rates in 2009. The co-circulation of influenza viruses during the pandemic and the circulation of influenza viruses during the preceding season were also associated with pandemic mortality rates. We found that real time assessments of 2009 pandemic mortality risk factors (e.g. obesity) probably led to a number of false positive findings.

Are Kenyan healthcare workers willing to receive the pandemic influenza vaccine? Results from a cross-sectional survey of healthcare workers in Kenya about knowledge, attitudes and practices concerning infection with and vaccination against 2009 pandemic influenza A (H1N1), 2010.

Over 1200 cases of 2009 pandemic influenza A H1N1 (pH1N1) have been identified in Kenya since the first case in June 2009. In April 2010 the Kenyan government launched a program to immunize high-risk groups and healthcare workers (HCWs) with pH1N1 vaccines donated by the World Health Organization. To characterize HCWs' knowledge, attitudes and practices regarding pH1N1 vaccination, we conducted a quantitative and qualitative survey in 20 healthcare facilities across Kenya between January 11 and 26, 2010. Of 659 HCWs interviewed, 55% thought there was a vaccine against pH1N1, and 89% indicated that they would receive pH1N1 vaccine if it became available. In focus group discussions, many HCWs said that pH1N1 virus infection did not cause severe disease in Kenyans and questioned the need for vaccination. However, most were willing to accept vaccination if they had adequate information on safety and efficacy. In order for the influenza vaccination campaign to be successful, HCWs must understand that pH1N1 can cause severe disease in Kenyans, that pH1N1 vaccination can prevent HCWs from transmitting influenza to their patients, and that the vaccine has been widely used globally with few recognized adverse events.