22. Description of Hospitalized Patients with Influenza Vaccine Failure

Abstract Background Despite influenza vaccination, some patients develop illness and require hospitalization. Many factors contribute to vaccine failure, including mismatch of the vaccine and circulating strains, waning immunity, timing of influenza season, age and patient comorbidities such as immune function. This study compared vaccinated, hospitalized patients with and without influenza. Methods This study used 2015–2019 Tennessee data from the US Hospitalized Adult Influenza Vaccine Effectiveness Network database. Enrolled patients were ≥ 18 years vaccinated for the current influenza season and admitted with an acute respiratory illness. Patient or surrogate interviews and medical chart abstractions were performed, and influenza vaccinations were confirmed by vaccine providers. Influenza PCR testing was performed in a research lab. Statistical analyses were performed with STATA and R using Pearson’s chi-squared, Kruskal-Wallis and Wilcoxon rank-sum tests and multivariate logistic regression. Results 1236 patients met study criteria, and 235 (19%) tested positive for influenza. Demographics, vaccines and comorbidities were similar between the two groups (Table 1) except for morbid obesity, which was more common in influenza negative patients (13% vs 8%, p = 0.04), and immunosuppression, which was more common in the influenza positive (63% vs 54%, p = 0.01). Logistic regression analysis demonstrated older patients (OR 1.47, 95% CI 1.03–2.10) and immunosuppressed patients (OR 1.56, 1.15–2.12) were at increased risk for influenza (Table 2 and Figure 1). Immunosuppression also increased the risk for influenza A/H3N2 (OR 1.86, 95% CI 1.25–2.75). A sensitivity analysis was performed on patients who self-reported influenza vaccination for the current season without vaccine verification and demonstrated increased risk of influenza in older adults (OR 1.66, 95% CI 1.16–2.39). Table 1: Demographics of influenza positive versus influenza negative patients in influenza vaccinated, hospitalized patients. Table 2: Logistic regression analyses of vaccinated, hospitalized influenza positive patients; vaccinated, hospitalized patients with influenza A subtypes and self-reported vaccinated, hospitalized influenza positive patients. Figure 1: Predicted Probability of Hospitalization with Influenza, Influenza A/H1N1 and Influenza A/H3N2 in Vaccinated Patients by Age. Conclusion Our study demonstrated an increased risk of influenza vaccine failure in older patients and immunosuppressed patients. These groups are also at increased risk for influenza complications. To improve protection of these patients against future influenza illnesses, more effective vaccines are needed, and more research on ring vaccination should be pursued. Disclosures All Authors: No reported disclosures

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Influenza Vaccine Failure Associated with Age and Immunosuppression

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa757 ◽

2020 ◽

Author(s):

Joanna Kimball ◽

Yuwei Zhu ◽

Dayna Wyatt ◽

Christopher H Trabue ◽

H Keipp Talbot

Keyword(s):

Logistic Regression ◽

Influenza Vaccine ◽

Older Patients ◽

Influenza A ◽

Influenza Infection ◽

Respiratory Illness ◽

Vaccine Failure ◽

Increased Risk ◽

Chi Squared ◽

Immunosuppressed Patients

Abstract Background The influenza vaccine is one of the best ways to prevent influenza infection, but little is known about influenza vaccine failure. Methods This study evaluated patients admitted for an acute respiratory illness during the 2015-2019 influenza seasons to compare vaccinated, influenza-negative patients to vaccinated, influenza-positive patients. Statistical analyses were performed with STATA and R using Pearson’s chi-squared, Kruskal-Wallis, Wilcoxon rank-sum tests and multivariate logistic regression. Results 1236 patients vaccinated for influenza were enrolled, of which 235 (19%) tested positive for influenza. Demographics, vaccines and comorbidities were similar between the groups except for morbid obesity (13% in the influenza negative vs. 8%, p=0.04), and immunosuppression (63% in the influenza positive vs. 54%, p=0.01). Logistic regression analysis demonstrated older patients (OR 1.47, 95%CI 1.03-2.10) and immunosuppressed patients (OR 1.56, 1.15-2.12) were at increased risk for influenza despite immunization. When evaluated by influenza subtype, immunosuppression was found to increase the risk for influenza A/H3N2 (OR 1.86, 95%CI 1.25-2.75). Conclusion Our study demonstrated increased risk of influenza vaccine failure in older patients and immunosuppressed patients. These groups are also at increased risk for influenza complications. To improve protection of patients against future influenza illnesses, more effective vaccines and strategies are needed.

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The impact of the 2009 influenza A(H1N1) pandemic on attitudes of healthcare workers toward seasonal influenza vaccination 2010/11

Eurosurveillance ◽

10.2807/ese.16.17.19854-en ◽

2011 ◽

Vol 16 (17) ◽

Author(s):

C Brandt ◽

H F Rabenau ◽

S Bornmann ◽

R Gottschalk ◽

S Wicker

Keyword(s):

Medical Students ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Healthcare Workers ◽

Influenza A ◽

Influenza Season ◽

University Hospital ◽

The Public ◽

Influenza A H1n1 ◽

The Impact

The emergence of the influenza A(H1N1)2009 virus provided a major challenge to health services around the world. However, vaccination rates for the public and for healthcare workers (HCWs) have remained low. We performed a study to review the reasons put forward by HCWs to refuse immunisation with the pandemic vaccine in 2009/10 and characterise attitudes in the influenza season 2010/11 due to the emergence of influenza A(H1N1)2009. A survey among HCWs and medical students in the clinical phase of their studies was conducted, using an anonymous questionnaire, at a German university hospital during an influenza vaccination campaign. 1,366 of 3,900 HCWs (35.0%) were vaccinated in the 2010/11 influenza season. Of the vaccinated HCWs, 1,323 (96.9%) completed the questionnaire in addition to 322 vaccinated medical students. Of the 1,645 vaccinees who completed the questionnaire, 712 had not been vaccinated against the influenza A(H1N1)2009 virus in the 2009/10 season. The main reason put forward was the objection to the AS03 adjuvants (239/712, 33.6%). Of the HCWs and students surveyed, 270 of 1,645 (16.4%) stated that the pandemic had influenced their attitude towards vaccination in general. Many German HCWs remained unconvinced of the safety of the pandemic (adjuvanted) influenza vaccine. For this reason, effective risk communication should focus on educating the public and HCWs about influenza vaccine safety and the benefits of vaccination.

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Determinants of influenza vaccine uptake and willingness to be vaccinated by pharmacists among the active adult population in Hungary: a cross-sectional exploratory study

BMC Public Health ◽

10.1186/s12889-021-10572-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Githa Fungie Galistiani ◽

Mária Matuz ◽

Nikolett Matuszka ◽

Péter Doró ◽

Krisztina Schváb ◽

...

Keyword(s):

Logistic Regression ◽

Risk Factor ◽

Influenza Vaccine ◽

Health Risk ◽

Influenza Vaccination ◽

Influenza Season ◽

Adult Population ◽

Vaccine Uptake ◽

Cross Sectional ◽

Vaccination Uptake

Abstract Background Many studies have addressed influenza vaccine uptake in risk-group populations (e.g. the elderly). However, it is also necessary to assess influenza vaccine uptake in the active adult population, since they are considered to be a high-transmitter group. In several countries pharmacists are involved in adult vaccination in order to increase uptake. This study therefore aimed to investigate the determinants of influenza vaccination uptake and examine the willingness to be vaccinated by pharmacists. Methods A cross-sectional study was conducted among Hungarian adults using a self-administered online questionnaire distributed via social media (Facebook). The questionnaire included five domains: demographics, vaccine uptake, factors that motivated or discouraged vaccination, knowledge and willingness of participants to accept pharmacists as influenza vaccine administrators. Descriptive statistics were applied and logistic regression was conducted to assess the possible determinants of vaccination uptake. Results Data from 1631 participants who completed the questionnaires were analysed. Almost 58% of respondents (944/1631) had occupational and/or health risk factors for influenza. Just over one-tenth (12.3%;200/1631) of participants were vaccinated during the 2017/18 influenza season, 15.4% (145/944) of whom had a risk factor for influenza. Approximately half of the participants (47.4%) believed that influenza vaccination can cause flu, and just over half of them (51.6%), were not knowledgeable about the safety of influenza vaccine ingredients. Logistic regression found that age, sex, health risk factor and knowledge on influenza/influenza vaccination were associated with influenza vaccination uptake (p < 0.05). The most frequently cited reason for having an influenza vaccination was self-protection (95.0%). The most common reason given for refusing the influenza vaccine was that the respondent stated they rarely had an infectious disease (67.7%). The number of participants who were willing to be vaccinated by pharmacists was two-times higher than the number of participants who were actually vaccinated during the 2017/18 influenza season. Conclusion Influenza vaccine uptake in the active adult population is low in Hungary. Public awareness and knowledge about influenza vaccination and influenza disease should be increased. The results also suggest a need to extend the role played by pharmacists in Hungary.

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Early season estimate of influenza vaccination effectiveness against influenza hospitalisation in children, Hong Kong, winter influenza season 2018/19

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.5.1900056 ◽

2019 ◽

Vol 24 (5) ◽

Cited By ~ 14

Author(s):

Susan S Chiu ◽

Mike YW Kwan ◽

Shuo Feng ◽

Eunice LY Chan ◽

Huiying Chua ◽

...

Keyword(s):

Hong Kong ◽

Confidence Interval ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Influenza A ◽

Influenza Season ◽

Public Hospitals ◽

Early Season ◽

Influenza A H1n1

The winter 2018/19 influenza season in Hong Kong has been predominated by influenza A(H1N1)pdm09 as at January 2019. We enrolled 2,016 children in three public hospitals in Hong Kong between 2 September 2018 and 11 January 2019. Using the test-negative approach, we estimated high early season effectiveness of inactivated influenza vaccine against influenza A or B of 90% (95% confidence interval (CI): 80–95%) and 92% (95% CI: 82–96%) against influenza A(H1N1)pdm09.

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Effects of Influenza Vaccination in the United States During the 2017–2018 Influenza Season

Clinical Infectious Diseases ◽

10.1093/cid/ciz075 ◽

2019 ◽

Vol 69 (11) ◽

pp. 1845-1853 ◽

Cited By ~ 78

Author(s):

Melissa A Rolfes ◽

Brendan Flannery ◽

Jessie R Chung ◽

Alissa O’Halloran ◽

Shikha Garg ◽

...

Keyword(s):

United States ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Influenza A ◽

Influenza Season ◽

Influenza Virus Infection ◽

The United States ◽

Influenza B ◽

Medical Visits ◽

Influenza A H1n1

Abstract Background The severity of the 2017–2018 influenza season in the United States was high, with influenza A(H3N2) viruses predominating. Here, we report influenza vaccine effectiveness (VE) and estimate the number of vaccine-prevented influenza-associated illnesses, medical visits, hospitalizations, and deaths for the 2017–2018 influenza season. Methods We used national age-specific estimates of 2017–2018 influenza vaccine coverage and disease burden. We estimated VE against medically attended reverse-transcription polymerase chain reaction–confirmed influenza virus infection in the ambulatory setting using a test-negative design. We used a compartmental model to estimate numbers of influenza-associated outcomes prevented by vaccination. Results The VE against outpatient, medically attended, laboratory-confirmed influenza was 38% (95% confidence interval [CI], 31%–43%), including 22% (95% CI, 12%–31%) against influenza A(H3N2), 62% (95% CI, 50%–71%) against influenza A(H1N1)pdm09, and 50% (95% CI, 41%–57%) against influenza B. We estimated that influenza vaccination prevented 7.1 million (95% CrI, 5.4 million–9.3 million) illnesses, 3.7 million (95% CrI, 2.8 million–4.9 million) medical visits, 109 000 (95% CrI, 39 000–231 000) hospitalizations, and 8000 (95% credible interval [CrI], 1100–21 000) deaths. Vaccination prevented 10% of expected hospitalizations overall and 41% among young children (6 months–4 years). Conclusions Despite 38% VE, influenza vaccination reduced a substantial burden of influenza-associated illness, medical visits, hospitalizations, and deaths in the United States during the 2017–2018 season. Our results demonstrate the benefit of current influenza vaccination and the need for improved vaccines.

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Interim 2018/19 influenza vaccine effectiveness: six European studies, October 2018 to January 2019

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.1900121 ◽

2019 ◽

Vol 24 (8) ◽

Cited By ~ 26

Author(s):

Esther Kissling ◽

Angela Rose ◽

Hanne-Dorthe Emborg ◽

Alin Gherasim ◽

Richard Pebody ◽

...

Keyword(s):

Older Adults ◽

Primary Care ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Influenza A ◽

Influenza Season ◽

Vaccine Effectiveness ◽

European Studies ◽

Influenza A H1n1

Influenza A(H1N1)pdm09 and A(H3N2) viruses both circulated in Europe in October 2018–January 2019. Interim results from six studies indicate that 2018/19 influenza vaccine effectiveness (VE) estimates among all ages in primary care was 32–43% against influenza A; higher against A(H1N1)pdm09 and lower against A(H3N2). Among hospitalised older adults, VE estimates were 34–38% against influenza A and slightly lower against A(H1N1)pdm09. Influenza vaccination is of continued benefit during the ongoing 2018/19 influenza season.

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Influenza vaccine effectiveness against all-cause mortality following laboratory-confirmed influenza in older adults, 2010-2011 to 2015-2016 seasons in Ontario, Canada

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1862 ◽

2020 ◽

Author(s):

Hannah Chung ◽

Sarah A Buchan ◽

Aaron Campigotto ◽

Michael A Campitelli ◽

Natasha S Crowcroft ◽

...

Keyword(s):

Older Adults ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Influenza A ◽

Vaccine Effectiveness ◽

Community Dwelling ◽

Administrative Databases ◽

Increased Risk ◽

Influenza A H1n1 ◽

All Cause Mortality

Abstract Background Older adults are at increased risk of mortality from influenza infections. We estimated influenza vaccine effectiveness (VE) against mortality following laboratory-confirmed influenza. Methods Using a test-negative design study and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against all-cause mortality following laboratory-confirmed influenza for community-dwelling adults aged >65 years during the 2010-2011 to 2015-2016 influenza seasons. Results Among 54,116 older adults tested for influenza across the 6 seasons, 6,837 died within 30 days of specimen collection. Thirteen percent (925 individuals) tested positive for influenza, and 50.6% were considered vaccinated for that season. Only 23.2% of influenza test-positive cases had influenza recorded as their underlying cause of death. Before and after multivariable adjustment, we estimated VE against all-cause mortality following laboratory-confirmed influenza to be 20% (95%CI, 8%-30%) and 20% (95%CI, 7%-30%), respectively. This estimate increased to 34% after correcting for influenza vaccination exposure misclassification. We observed significant VE against deaths following influenza confirmation during 2014-2015 (VE=26% [95%CI, 5%-42%]). We also observed significant VE against deaths following confirmation of influenza A/H1N1 and A/H3N2, and against deaths with COPD as the underlying cause. Conclusions These results support the importance of influenza vaccination in older adults, who account for most influenza-associated deaths annually.

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Coverage and Timing of Influenza Vaccination Among Privately Insured Pregnant Women in the United States, 2010-2018

Public Health Reports ◽

10.1177/00333549211026779 ◽

2021 ◽

pp. 003335492110267

Author(s):

Kai Hong ◽

Megan C. Lindley ◽

Fangjun Zhou

Keyword(s):

Influenza Vaccination ◽

Pregnant Women ◽

Vaccination Coverage ◽

Influenza Season ◽

The United States ◽

Metropolitan Statistical Area ◽

Provider Education ◽

Vaccination Uptake ◽

Increased Risk ◽

Privately Insured

Objective Pregnant women are at increased risk of serious complications from influenza and are recommended to receive an influenza vaccination during pregnancy. The objective of this study was to assess trends, timing patterns, and associated factors of influenza vaccination among pregnant women. Methods We used 2010-2018 MarketScan data on 1 286 749 pregnant women aged 15-49 who were privately insured to examine trends and timing patterns of influenza vaccination coverage. We examined descriptive statistics and identified factors associated with vaccination uptake by using multivariate log-binomial and Cox proportional hazard models. Results In-plan influenza vaccination coverage before delivery increased from 22.0% during the 2010-2011 influenza season to 33.2% during the 2017-2018 influenza season. About two-thirds of vaccinated women received the vaccine in September or October during each influenza season. For women who delivered in September through May, influenza vaccination coverage increased rapidly at the beginning of influenza season and flattened after October. For women who delivered in June through August, influenza vaccination coverage increased gradually until February and flattened thereafter. Most vaccinated women who delivered before January received the vaccine in the third trimester. Increased likelihood of being vaccinated was associated with age 31-40, living in a metropolitan statistical area, living outside the South, enrollment in a consumer-driven or high-deductible health plan, being spouses or dependents of policy holders, and delivery in November through January. Conclusions Despite increases during the past several years, vaccination uptake is still suboptimal, particularly after October. Health care provider education on timing of vaccination and recommendations throughout influenza seasons are needed to improve influenza vaccination coverage among pregnant women.

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Influenza vaccine in COVID-19 patients: Who?, why?, when?

Pneumologia ◽

10.2478/pneum-2021-0004 ◽

2021 ◽

Vol 69 (3) ◽

pp. 151-158

Author(s):

Raluca Ioana Dospinescu Arcana ◽

Radu Crișan-Dabija ◽

Anda Tesloianu ◽

Daniela Robu Popa ◽

Oana-Elena Rohozneanu ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza Vaccination ◽

Influenza A ◽

Structural Features ◽

Cold Season ◽

Influenza Viruses ◽

Double Infection ◽

Protective Measures ◽

Related Mode ◽

Evolution Approach

Abstract Considering the increased prevalence of influenza infections in the cold season and the pandemic evolution of severe acute respiratory syndrome-CoV-2 (SARS-CoV-2), the medical staffs are facing potential viral co-infection with SARS-CoV-2 and influenza virus. Both viruses belong to the category of ribonucleic acid (RNA) viruses, having common structural features, causing a similar immune response, with a related mode of transmission and with both respiratory and general symptoms. SARS-CoV-2 and influenza viruses cause contagious infections and the protective measures against them are the same: wearing masks in crowded spaces, proper hand hygiene and avoiding crowded places. Co-infections with influenza A and B viruses and SARS-CoV-2 virus involve additional precautions regarding the therapeutic and evolution approach. Studies show that patients who have been vaccinated against influenza have developed milder forms of confirmed SARS-CoV-2 infection. In elderly patients, increased influenza vaccination coverage has shown to be associated with a decrease in mortality rate and also reduced the heavy impact of double infection. The Influenza vaccine can trigger early immune mechanisms in order to facilitate early detection of SARS-CoV-2 as well as its clearance. Influenza vaccination should now be seen, more than ever, as a strategy to combat the growing SARS-CoV-2 pandemic, especially in vulnerable populations (elderly and people with associated comorbidities).

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Influenza Vaccination Hesitancy among Healthcare Workers in South Al Batinah Governorate in Oman: A Cross-Sectional Study

Vaccines ◽

10.3390/vaccines8040661 ◽

2020 ◽

Vol 8 (4) ◽

pp. 661

Author(s):

Salah T. Al Awaidy ◽

Zayid K. Al Mayahi ◽

Malak Kaddoura ◽

Ozayr Mahomed ◽

Nathalie Lahoud ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza Vaccination ◽

Healthcare Workers ◽

Seasonal Influenza ◽

General Medicine ◽

Knowledge Score ◽

Vaccine Uptake ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Increased Risk

Background: Seasonal influenza infections are a major cause of morbidity and mortality worldwide. Healthcare workers (HCWs) are an important target group for vaccination against influenza due to their increased risk of infection and their potential to transmit the infection to their patients, families and communities. The aim of this study was to assess the potential hesitancy and its associated factors towards influenza vaccination amongst HCWs in the South Al Batinah governorate in Oman. Methods: A cross-sectional survey of 390 HCWs with direct or indirect patient contact was conducted in May and June 2019 using a self-administered questionnaire. Associations between HCW characteristics and vaccination status were examined using bivariate and multivariate analyses to identify the likelihood of vaccination against seasonal influenza among HCWs. Results: Overall, 60% of HCWs were vaccinated in the 2018/2019 season; vaccine uptake among nurses was 52% and uptake was higher among women. Self-protection and protection of the community were the most cited reasons for vaccine acceptance, with side effects being the main reason for hesitancy. Vaccinated respondents had a higher mean knowledge score (7.18; standard deviation SD: 2.14) than unvaccinated respondents (6.30; SD: 2.2). Odds of vaccination were highest among respondents who believed influenza vaccine should be mandatory for HCWs (Odds ratio (OR): 2.04 [1.30–3.18]), those working in the general medicine, emergency medicine, or intensive care units (OR: 1.92 [1.20–3.10]), nurses and doctors (OR: 1.75 [1.09–2.79]) and those who believe that HCWs should receive an influenza vaccine (OR: 1.35 [1.07–2.77]). Conclusions: The study provides valuable insights into the enablers and barriers of influenza vaccination practices among HCWs and may inform interventions to increase acceptance of vaccination.

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