Prevention of Influenza Hospitalization Among Adults in the United States, 2015–2016: Results From the US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN)

Abstract Background Evidence establishing effectiveness of influenza vaccination for prevention of severe illness is limited. The US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) is a multiyear test-negative case-control study initiated in 2015–2016 to estimate effectiveness of vaccine in preventing influenza hospitalization among adults. Methods Adults aged ≥18 years admitted to 8 US hospitals with acute respiratory illness and testing positive for influenza by polymerase chain reaction were cases; those testing negative were controls. Vaccine effectiveness was estimated with logistic regression adjusting for age, comorbidities, and other confounding factors and stratified by frailty, 2-year vaccination history, and clinical presentation. Results We analyzed data from 236 cases and 1231 controls; mean age was 58 years. More than 90% of patients had ≥1 comorbidity elevating risk of influenza complications. Fifty percent of cases and 70% of controls were vaccinated. Vaccination was 51% (95% confidence interval [CI], 29%–65%) and 53% (95% CI, 11%–76%) effective in preventing hospitalization due to influenza A(H1N1)pdm09 and influenza B virus infection, respectively. Vaccine was protective for all age groups. Conclusions During the 2015–2016 US influenza A(H1N1)pdm09–predominant season, we found that vaccination halved the risk of influenza-association hospitalization among adults, most of whom were at increased risk of serious influenza complications due to comorbidity or age.

Download Full-text

Age-specific vaccine effectiveness of seasonal 2010/2011 and pandemic influenza A(H1N1) 2009 vaccines in preventing influenza in the United Kingdom

Epidemiology and Infection ◽

10.1017/s0950268812001148 ◽

2012 ◽

Vol 141 (3) ◽

pp. 620-630 ◽

Cited By ~ 30

Author(s):

R. G. PEBODY ◽

N. ANDREWS ◽

D. M. FLEMING ◽

J. McMENAMIN ◽

S. COTTRELL ◽

...

Keyword(s):

Influenza Vaccine ◽

Pandemic Influenza ◽

Influenza A ◽

Vaccine Effectiveness ◽

Influenza B ◽

The United Kingdom ◽

Previous Season ◽

Negative Case ◽

Influenza A H1n1 ◽

Control Study

SUMMARYAn analysis was undertaken to measure age-specific vaccine effectiveness (VE) of 2010/11 trivalent seasonal influenza vaccine (TIV) and monovalent 2009 pandemic influenza vaccine (PIV) administered in 2009/2010. The test-negative case-control study design was employed based on patients consulting primary care. Overall TIV effectiveness, adjusted for age and month, against confirmed influenza A(H1N1)pdm 2009 infection was 56% (95% CI 42–66); age-specific adjusted VE was 87% (95% CI 45–97) in <5-year-olds and 84% (95% CI 27–97) in 5- to 14-year-olds. Adjusted VE for PIV was only 28% (95% CI −6 to 51) overall and 72% (95% CI 15–91) in <5-year-olds. For confirmed influenza B infection, TIV effectiveness was 57% (95% CI 42–68) and in 5- to 14-year-olds 75% (95% CI 32–91). TIV provided moderate protection against the main circulating strains in 2010/2011, with higher protection in children. PIV administered during the previous season provided residual protection after 1 year, particularly in the <5 years age group.

Download Full-text

2553. Individual Patient-Level Data Meta-Analysis of Live Attenuated and Inactivated Influenza Vaccine Effectiveness Among US Children, 2013–2014 Through 2015–2016

Open Forum Infectious Diseases ◽

10.1093/ofid/ofy209.161 ◽

2018 ◽

Vol 5 (suppl_1) ◽

pp. S68-S68

Author(s):

Jessie Chung ◽

Brendan Flannery ◽

Rodolfo Begue ◽

Herve Caspard ◽

Laurie Demarcus ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

The United States ◽

Vaccine Effectiveness ◽

Vaccination Status ◽

Influenza B ◽

Rt Pcr ◽

Current Season ◽

Influenza A H1n1 ◽

Vaccine Type

Abstract Background Quadrivalent live attenuated influenza vaccine (LAIV4) was not recommended for use in the United States for the 2016–2017 and 2017–2018 influenza seasons based on US observational studies of vaccine effectiveness (VE) from 2013–2014 to 2015–2016. We pooled individual patient data on children aged 2–17 years enrolled in 5 US studies during these 3 influenza seasons to further investigate VE by vaccine type. Methods Analyses included 17,173 children enrolled in the US Department of Defense Global Laboratory-based Influenza Surveillance Program, US Influenza Vaccine Effectiveness Network, Influenza Incidence Surveillance Project, Influenza Clinical Investigation for Children, and a Louisiana State University study. Participants’ specimens were tested for influenza by reverse transcription-polymerase chain reaction (RT-PCR), culture, or a combination of rapid antigen testing and RT-PCR. VE was calculated by comparing odds of vaccination with either inactivated influenza vaccine (IIV) or LAIV4 among influenza-positive cases to test-negative controls and calculated as 100 × (1 − odds ratio) in logistic regression models with age, calendar time, influenza season, and study site (random effect). Patients were stratified by prior season vaccination status in a subanalysis. Results Overall, 38% of patients (N = 6,558) were vaccinated in the current season, of whom 30% (N = 1,979) received LAIV4. Pooled VE of IIV against any influenza virus was 51% (95% CI: 47, 54) versus 26% (95% CI: 15, 36) for LAIV4. Point estimates for pooled VE against any influenza by age group ranged from 45% to 58% for IIV and 19% to 34% for LAIV4 during the 3 seasons (Figures 1 and 2). Pooled VE against influenza A(H1N1)pdm09 was 67% (95% CI: 62, 72) for IIV versus 20% (95% CI: −6, 39) for LAIV4. Pooled VE against influenza A(H3N2) was 29% (95% CI: 14, 42) for IIV versus 7% (95% CI: −11, 23) for LAIV4, and VE against influenza B was 52% (95% CI: 42, 60) for IIV and 66% (95% CI: 47, 77) for LAIV4. VE against influenza A(H1N1)pdm09 was lower for LAIV4 versus IIV across all strata of prior season vaccination (Figure 3). Conclusion Consistent with individual studies, our pooled analyses found that LAIV4 effectiveness was reduced for all age groups against influenza A(H1N1)pdm09 compared with IIV. This result did not vary based on prior vaccination status. Disclosures H. Caspard, AstraZeneca: Employee, Salary.

Download Full-text

Influenza vaccine effectiveness in adults 65 years and older, Denmark, 2015/16 – a rapid epidemiological and virological assessment

Eurosurveillance ◽

10.2807/1560-7917.es.2016.21.14.30189 ◽

2016 ◽

Vol 21 (14) ◽

Cited By ~ 16

Author(s):

Hanne Dorthe Emborg ◽

Tyra Grove Krause ◽

Lene Nielsen ◽

Marianne Kragh Thomsen ◽

Claus Bohn Christiansen ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Control Design ◽

Case Control ◽

Vaccine Effectiveness ◽

Influenza B ◽

Trivalent Influenza Vaccine ◽

Negative Case ◽

Influenza A H1n1 ◽

Genetic Subgroup

In Denmark, both influenza A(H1N1)pdm09 and influenza B co-circulated in the 2015/16 season. We estimated the vaccine effectiveness (VE) of the trivalent influenza vaccine in patients 65 years and older using the test-negative case–control design. The adjusted VE against influenza A(H1N1)pdm09 was 35.0% (95% confidence interval (CI): 11.1–52.4) and against influenza B 4.1% (95% CI: −22.0 to 24.7). The majority of influenza A(H1N1)pdm09 circulating in 2015/16 belonged to the new genetic subgroup subclade 6B.1.

Download Full-text

Inactivated influenza vaccine effectiveness among department of defense beneficiaries aged 6 months-17 years, 2016–2017 through 2019–2020 influenza seasons

PLoS ONE ◽

10.1371/journal.pone.0256165 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0256165

Author(s):

Wenping Hu ◽

Laurie S. DeMarcus ◽

Paul A. Sjoberg ◽

Anthony S. Robbins

Keyword(s):

Influenza Vaccine ◽

Department Of Defense ◽

Influenza A ◽

Linear Mixed Model ◽

Vaccine Effectiveness ◽

Respiratory Pathogen ◽

Surveillance Program ◽

Influenza B ◽

Negative Case ◽

Influenza A H1n1

A test-negative case-control study was conducted to assess inactivated influenza vaccine effectiveness (VE) in children aged 6 months-17 years. The database was developed from the US Department of Defense Global Respiratory Pathogen Surveillance Program over four consecutive influenza seasons from 2016 to 2020. A total of 9,385 children including 4,063 medically attended, laboratory-confirmed influenza-positive cases were identified for VE analysis. A generalized linear mixed model with logit link and binomial distribution was used to estimate the VE. The adjusted VE for children was 42% [95% confidence interval (CI): 37–47%] overall, including 55% (95% CI: 47–61%) for influenza A(H1N1)pdm09, 37% (95% CI: 28–45%) for influenza A(H3N2), and 49% (95% CI: 41–55%) for influenza B. The analysis by age groups indicated that the adjusted VE in children aged 6 months-4 years was higher against influenza A(H1N1)pdm09 and influenza B, and comparable against influenza A(H3N2), compared to those in children aged 5–17 years. Further age-stratified analysis showed that the VE against any types of influenza was low and non-significant for children aged 6–11 months (33%; 95% CI:-2-56%), but it was high (54%; 95% CI: 34–67%) in children aged 12–23 months, and then declined linearly with increasing age. In conclusion, the inactivated influenza vaccination was moderately effective against influenza infection, based on the analysis from a large number of children aged 6 months-17 years over multiple influenza seasons.

Download Full-text

Influenza vaccine effectiveness against laboratory-confirmed influenza in hospitalised adults aged 60 years or older, Valencia Region, Spain, 2017/18 influenza season

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.31.1800461 ◽

2019 ◽

Vol 24 (31) ◽

Author(s):

Ainara Mira-Iglesias ◽

F Xavier López-Labrador ◽

Víctor Baselga-Moreno ◽

Miguel Tortajada-Girbés ◽

Juan Mollar-Maseres ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Vaccine Effectiveness ◽

Influenza Viruses ◽

Influenza B ◽

Current Season ◽

Hospitalised Patients ◽

Influenza A H1n1 ◽

Vaccine Type ◽

The Impact

Introduction Influenza immunisation is recommended for elderly people each season. The influenza vaccine effectiveness (IVE) varies annually due to influenza viruses evolving and the vaccine composition. Aim To estimate, in inpatients ≥ 60 years old, the 2017/18 trivalent IVE, overall, by vaccine type and by strain. The impact of vaccination in any of the two previous seasons (2016/17 and 2015/16) on current (2017/18) IVE was also explored. Methods This was a multicentre prospective observational study within the Valencia Hospital Surveillance Network for the Study of Influenza and Respiratory Viruses Disease (VAHNSI, Spain). The test-negative design was applied taking laboratory-confirmed influenza as outcome and vaccination status as main exposure. Information about potential confounders was obtained from clinical registries and/or by interviewing patients; vaccine information was only ascertained by registries. Results Overall, 2017/18 IVE was 9.9% (95% CI: −15.5 to 29.6%), and specifically, 48.3% (95% CI: 13.5% to 69.1%), −29.9% (95% CI: −79.1% to 5.8%) and 25.7% (95% CI: −8.8% to 49.3%) against A(H1N1)pdm09, A(H3N2) and B/Yamagata lineage, respectively. For the adjuvanted and non-adjuvanted vaccines, overall IVE was 10.0% (95% CI: −24.4% to 34.9%) and 7.8% (95% CI: −23.1% to 31.0%) respectively. Prior vaccination significantly protected against influenza B/Yamagata lineage (IVE: 50.2%; 95% CI: 2.3% to 74.6%) in patients not vaccinated in the current season. For those repeatedly vaccinated against influenza A(H1N1)pdm09, IVE was 46.4% (95% CI: 6.8% to 69.2%). Conclusion Our data revealed low vaccine effectiveness against influenza in hospitalised patients ≥60 years old in 2017/18. Prior vaccination protected against influenza A(H1N1)pdm09 and B/Yamagata-lineage.

Download Full-text

Uptake and effectiveness of influenza vaccine in those aged 65 years and older in the United Kingdom, influenza seasons 2010/11 to 2016/17

Eurosurveillance ◽

10.2807/1560-7917.es.2018.23.39.1800092 ◽

2018 ◽

Vol 23 (39) ◽

Cited By ~ 10

Author(s):

Richard G Pebody ◽

Fiona Warburton ◽

Nick Andrews ◽

Mary Sinnathamby ◽

Ivelina Yonova ◽

...

Keyword(s):

United Kingdom ◽

Influenza Vaccine ◽

Influenza A ◽

Vaccine Uptake ◽

Attributable Mortality ◽

Influenza B ◽

Age Group ◽

The United Kingdom ◽

Negative Case ◽

Influenza A H1n1

Background In 2016/17, seasonal influenza vaccine was less effective in those aged 65 years and older in the United Kingdom. We describe the uptake, influenza-associated mortality and adjusted vaccine effectiveness (aVE) in this age group over influenza seasons 2010/11–2016/17. Methods: Vaccine uptake in 2016/17 and five previous seasons were measured using a sentinel general practitioners cohort in England; the test-negative case-control design was used to estimate pooled aVE by subtype and age group against laboratory-confirmed influenza in primary care from 2010–2017. Results: Vaccine uptake was 64% in 65–69-year-olds, 74% in 70–74-year-olds and 80% in those aged 75 and older. Overall aVE was 32.5% (95% CI: 11.6 to 48.5); aVE by sub-type was 60.8% (95% CI: 33.9 to 76.7) and 50.0% (95% CI: 21.6 to 68.1) against influenza A(H1N1)pdm09 and influenza B, respectively, but only 5.6% (95% CI: - 39.2 to 35.9) against A(H3N2). Against all laboratory-confirmed influenza aVE was 45.2% (95% CI: 25.1 to 60.0) in 65–74 year olds; - 26.2% (95% CI: - 149.3 to 36.0) in 75–84 year olds and - 3.2% (95% CI: - 237.8 to 68.5) in those aged 85 years and older. Influenza-attributable mortality was highest in seasons dominated by A(H3N2). Conclusions: Vaccine uptake with non-adjuvanted, normal-dose vaccines remained high, with evidence of effectiveness against influenza A(H1N1)pdm09 and B, though poor against A(H3N2), particularly in those aged 75 years and older. Forthcoming availability of newly licensed vaccines with wider use of antivirals can potentially further improve prevention and control of influenza in this group.

Download Full-text

899. Influenza Vaccine Effectiveness Against Laboratory-Confirmed Influenza in Children Hospitalized with Respiratory Illness in the United States, 2016–2017 and 2017–2018 Seasons

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz359.058 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S26-S27

Author(s):

Angela P Campbell ◽

Constance E Ogokeh ◽

Craig McGowan ◽

Brian Rha ◽

Rangaraj Selvarangan ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Respiratory Illness ◽

The United States ◽

Vaccine Effectiveness ◽

Severe Illness ◽

Surveillance Network ◽

Pediatric Hospitals ◽

Significant Difference ◽

National Estimates

Abstract Background Annual national estimates of influenza vaccine effectiveness (VE) typically measure protection against outpatient medically attended influenza illness. We assessed influenza VE in preventing laboratory-confirmed influenza hospitalization in children across two influenza A(H3N2)-predominant seasons. Methods Children < 18 years hospitalized with acute respiratory illness were enrolled at 7 pediatric hospitals in the New Vaccine Surveillance Network. We included subjects ≥6 months with ≤10 days of symptoms enrolled during the 2016–2017 and 2017–2018 seasons (date of first through last influenza-positive case for each site). Combined mid-turbinate and throat swabs were tested using molecular assays. We estimated age-stratified VE from a test-negative design using logistic regression to compare the odds of vaccination among cases positive for influenza with controls testing negative, adjusting for age, enrollment month, site, underlying comorbidities, and race/ethnicity. Full/partial vaccination was defined using ACIP criteria. We verified vaccine receipt from state immunization registries and/or provider records. Results Among 3441 children with complete preliminary data, in 2016–2017, 156/1,710 (9%) tested positive for influenza: 91 (58%) with influenza A(H3N2), 5 (3%) with A(H1N1), and 60 (38%) with B viruses. In 2017–2018, 193/1,731 (11%) tested positive: 87 (45%) with influenza A(H3N2), 47 (24%) with A(H1N1), and 58 (30%) with B. VE for all vaccinated children (full and partial) against any influenza was 48% (95% confidence interval, 26%–63%) in 2016–2017 and 45% (24%–60%) in 2017–2018. Combining seasons, VE for fully and partially vaccinated children against any influenza type was 46% (32%–58%); by virus, VE was 30% (4%–49%) for influenza A(H3N2), 71% (46%–85%) for A(H1N1), and 57% (36%–70%) for B viruses. There was no statistically significant difference in VE by age or full/partial vaccination status for any virus (table). Conclusion Vaccination in the 2016–2017 and 2017–2018 seasons nearly halved the risk of children being hospitalized with influenza. These findings support the use of vaccination to prevent severe illness in children. Our study highlights the need for a better understanding of the lower VE against influenza A(H3N2) viruses. Disclosures All Authors: No reported Disclosures.

Download Full-text

Vaccine effectiveness against influenza-associated hospitalizations among adults, 2018-2019, US Hospitalized Adult Influenza Vaccine Effectiveness Network

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa772 ◽

2020 ◽

Author(s):

J M Ferdinands ◽

M Gaglani ◽

S Ghamande ◽

E T Martin ◽

D Middleton ◽

...

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Influenza Season ◽

Respiratory Illness ◽

Vaccine Effectiveness ◽

H3n2 Virus ◽

Influenza A H1n1 ◽

The Us ◽

Middle Aged Adults ◽

Residual Confounding

Abstract We estimated vaccine effectiveness for prevention of influenza-associated hospitalizations among adults during the 2018-2019 influenza season. Adults admitted with acute respiratory illness to 14 hospitals of the US Hospitalized Adult Influenza Vaccine Effectiveness Network and testing positive for influenza were cases; patients testing negative were controls. Vaccine effectiveness was estimated using logistic regression and inverse probability of treatment weighting. We analyzed data from 2863 patients with mean age of 63 years. Adjusted VE against influenza A(H1N1)pdm09-associated hospitalization was 51% (95%CI 25, 68). Adjusted VE against influenza A(H3N2) virus-associated hospitalization was −2% (95%CI −65, 37) and differed significantly by age, with VE of −130% (95% CI −374, −27) among adults 18 to ≤56 years of age. Although vaccination halved the risk of influenza-A(H1N1)pdm09-associated hospitalizations, it conferred no protection against influenza A(H3N2)-associated hospitalizations. We observed negative VE for young-and middle-aged adults but cannot exclude residual confounding as a potential explanation.

Download Full-text

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza A(H1N1)pdm09 and B among elderly people in Europe: results from the I-MOVE+ project

Eurosurveillance ◽

10.2807/1560-7917.es.2017.22.30.30580 ◽

2017 ◽

Vol 22 (30) ◽

Cited By ~ 16

Author(s):

Marc Rondy ◽

Amparo Larrauri ◽

Itziar Casado ◽

Valeria Alfonsi ◽

Daniela Pitigoi ◽

...

Keyword(s):

Diabetes Mellitus ◽

Heart Disease ◽

Elderly People ◽

Influenza A ◽

Vaccine Effectiveness ◽

Influenza B ◽

Negative Case ◽

Severe Acute Respiratory Infection ◽

Influenza A H1n1 ◽

Patients With Diabetes

We conducted a multicentre test-negative case–control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged ≥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases.

Download Full-text

Circulating influenza viruses and the effectiveness of seasonal influenza vaccine in Romania, season 2012-2013 / Virusurile gripale circulante și eficacitatea vaccinului gripal sezonier în România, în sezonul 2012-2013

Revista Romana de Medicina de Laborator ◽

10.1515/rrlm-2015-0007 ◽

2015 ◽

Vol 23 (1) ◽

Author(s):

Daniela Pitigoi ◽

George Necula ◽

Viorel Alexandrescu ◽

Maria Elena Mihai ◽

Carmen Maria Cherciu ◽

...

Keyword(s):

Influenza Vaccine ◽

Vaccine Strain ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Viruses ◽

Nucleotide Sequencing ◽

Influenza B ◽

Seasonal Influenza Vaccine ◽

Negative Case ◽

Influenza A H1n1

AbstractBackgound. Using influenza epidemiological and virological surveillance data, we aimed at investigating the profile of influenza viruses circulating in Romania during the season 2012-2013 and estimating the effectiveness (VE) of the seasonal vaccine. Methods. We tested all specimens collected from patients with influenza like illness (ILI) in the national surveillance system between week 40/2012 to week 20/2013. Influenza A/B positive specimens identified by molecular detection (RT-PCR) were further characterized. We used hemagglutination inhibition assay for antigenic characterization and chemiluminiscence assay for the antiviral susceptibility testing. Subsequently we conducted nucleotide sequencing of hemagglutinin and neuraminidase genes and phylogenetic tree analyses. We estimated influenza VE using the test negative case-control study design, as 1-odds ratio of vaccination among ILI cases positive for influenza and ILI negative controls. Results and Discussions. We tested 1087 specimens, and 537 cases were positive (56.2% influenza B, 40.6% A(H1N1)pdm09, 3.2% A(H3N2). Sixty-four influenza viruses were antigenically and/or genetically characterized. A(H1N1)pdm09 viruses were related to the vaccine strain A/ California/07/2009 and clustered with genetic group 6 similar to A/St. Petersburg/27/2011. Influenza B viruses belonged to clade 2 of type B/Yamagata lineage, related to B/Estonia/55669/2011 except one, B/Victoria lineage, representative strain B/Brisbane/60/2008. A(H3) viruses clustered with group 3C of the A/Victoria/208/2009 clade, similar to the vaccine strain A/Victoria/361/2011. All tested strains (57) demonstrated susceptibility to oseltamivir and zanamivir. The adjusted seasonal influenza vaccine effectiveness against influenza A(H1N1)pdm09 (N=119) was 76.9% (95% CI: -113.4, 98.5), suggesting a good protection, consistent with the good match between the vaccine and circulating strains.

Download Full-text