Trivalent inactivated influenza vaccine effective against influenza A(H3N2) variant viruses in children during the 2014/15 season, Japan

The 2014/15 influenza season in Japan was characterised by predominant influenza A(H3N2) activity; 99% of influenza A viruses detected were A(H3N2). Subclade 3C.2a viruses were the major epidemic A(H3N2) viruses, and were genetically distinct from A/New York/39/2012(H3N2) of 2014/15 vaccine strain in Japan, which was classified as clade 3C.1. We assessed vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children aged 6 months to 15 years by test-negative case–control design based on influenza rapid diagnostic test. Between November 2014 and March 2015, a total of 3,752 children were enrolled: 1,633 tested positive for influenza A and 42 for influenza B, and 2,077 tested negative. Adjusted VE was 38% (95% confidence intervals (CI): 28 to 46) against influenza virus infection overall, 37% (95% CI: 27 to 45) against influenza A, and 47% (95% CI: -2 to 73) against influenza B. However, IIV was not statistically significantly effective against influenza A in infants aged 6 to 11 months or adolescents aged 13 to 15 years. VE in preventing hospitalisation for influenza A infection was 55% (95% CI: 42 to 64). Trivalent IIV that included A/New York/39/2012(H3N2) was effective against drifted influenza A(H3N2) virus, although vaccine mismatch resulted in low VE.

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Effectiveness of influenza vaccine in preventing medically-attended influenza virus infection in primary care, Israel, influenza seasons 2014/15 and 2015/16

Eurosurveillance ◽

10.2807/1560-7917.es.2018.23.7.17-00026 ◽

2018 ◽

Vol 23 (7) ◽

Cited By ~ 11

Author(s):

Hamutal Yaron-Yakoby ◽

Hanna Sefty ◽

Rakefet Pando ◽

Rita Dichtiar ◽

Mark A Katz ◽

...

Keyword(s):

Primary Care ◽

Influenza Virus ◽

Influenza Vaccine ◽

Influenza A ◽

Influenza Season ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Influenza B ◽

Negative Case ◽

Influenza A H1n1

Introduction Influenza vaccine is recommended for the entire population in Israel. We assessed influenza vaccine effectiveness (VE) for the 2014/15 and 2015/16 seasons in Israel, for the first time. Methods: Combined nose and throat swab specimens were collected from patients with influenza-like illness (ILI) presenting to sentinel primary care clinics and tested for influenza virus by RT-PCR. VE of the trivalent inactivated vaccine (TIV) was assessed using test-negative case–control design. Results: During the 2014/15 season 1,142 samples were collected; 327 (28.6%) were positive for influenza, 83.8% A(H3N2), 5.8% A(H1N1)pdm09, 9.2% B and 1.2% A un-subtyped. Adjusted VE against all influenza viruses for this influenza season was −4.8% (95% confidence interval (CI): −54.8 to 29.0) and against influenza A(H3N2), it was −15.8% (95% CI: −72.8 to 22.4). For the 2015/16 season, 1,919 samples were collected; 853 (44.4%) were positive for influenza, 43.5% A(H1N1)pdm09, 57% B, 0.7% A(H3N2) and 11 samples positive for both A(H1N1)pdm09 and B. Adjusted VE against all influenza viruses for this influenza season was 8.8% (95% CI: −25.1 to 33.5), against influenza A(H1N1)pdm09, it was 32.3% (95% CI: (−4.3 to 56.1) and against influenza B, it was −2.2% (95% CI: (−47.0 to 29.0). Conclusions: Using samples from patients with ILI visiting sentinel clinics in Israel, we demonstrated the feasibility of influenza VE estimation in Israel.

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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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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.

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Public health implications of influenza B outbreaks in closed settings in the United Kingdom in the 2007/08 influenza season

Eurosurveillance ◽

10.2807/ese.13.38.18986-en ◽

2008 ◽

Vol 13 (38) ◽

Author(s):

P Mook ◽

J Ellis ◽

J M Watson ◽

CI Thompson ◽

M Zambon ◽

...

Keyword(s):

Public Health ◽

United Kingdom ◽

Burden Of Disease ◽

Influenza A ◽

Health Management ◽

Influenza Season ◽

Influenza B ◽

Influenza A Viruses ◽

School Aged Children ◽

The United Kingdom

Several influenza B outbreaks occurred in closed settings late in the 2007/08 influenza season (October to mid-May) in the United Kingdom (UK), with implications for public health management. Influenza B viruses usually circulate late in the season and cause a milder disease than influenza A viruses [1]. Epidemics of influenza B usually occur every two to three years with the burden of disease falling predominantly on school-aged children [2].

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Evaluation of Influenza Vaccine Effectiveness Among Young Children Receiving Consecutive Versus Nonconsecutive Vaccination During Influenza A(H3N2)-Predominant Seasons

Journal of the Pediatric Infectious Diseases Society ◽

10.1093/jpids/piaa080 ◽

2020 ◽

Author(s):

Suchitra Rao ◽

Angela Moss ◽

Molly M Lamb ◽

Edwin J Asturias

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Care Setting ◽

Case Control ◽

Vaccine Effectiveness ◽

Urgent Care ◽

Control Analysis ◽

Negative Case ◽

Case Control Analysis ◽

Urgent Care Setting

Abstract A test-negative case-control analysis of 1478 children aged 6 months to 8 years of age seeking care at an emergency/urgent care setting with influenza like illness during the 2016-17 and 2018-19 (H3N2 predominant) influenza seasons demonstrated that influenza vaccine effectiveness did not vary significantly by the prior seasons’ vaccination status. Clinical Trials Registration NCT02979626.

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Dual and Triple Infections With Influenza A and B Viruses: A Case-Control Study in Southern Brazil

The Journal of Infectious Diseases ◽

10.1093/infdis/jiz221 ◽

2019 ◽

Vol 220 (6) ◽

pp. 961-968 ◽

Cited By ~ 6

Author(s):

Tatiana Schäffer Gregianini ◽

Ivana R Santos Varella ◽

Patricia Fisch ◽

Letícia Garay Martins ◽

Ana B G Veiga

Keyword(s):

Influenza Virus ◽

Influenza A ◽

Clinical Symptoms ◽

Antiviral Treatment ◽

Influenza Virus Infection ◽

H3n2 Virus ◽

Influenza Surveillance ◽

Influenza B Virus ◽

Influenza B ◽

Influenza A H1n1

Abstract Influenza surveillance is important for disease control and should consider possible coinfection with different viruses, which can be associated with disease severity. This study analyzed 34 459 patients with respiratory infection from 2009 to 2018, of whom 8011 were positive for influenza A virus (IAV) or influenza B virus (IBV). We found 18 cases of dual influenza virus infection, including coinfection with 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09) and influenza A(H3N2) virus (1 case), A(H1N1)pdm09 and IBV (6 cases), A(H3N2) and IBV (8 cases), and nonsubtyped IAV and IBV (3 cases); and 1 case of triple infection with A(H3N2), A(H1N1)pdm09, and IBV. Compared with 76 monoinfected patients, coinfection was significantly associated with cardiopathy and death. Besides demographic characteristics and clinical symptoms, we assessed vaccination status, antiviral treatment, timeliness of antiviral use, hospitalization, and intensive care unit admission, but no significant differences were found between coinfected and monoinfected cases. Our findings indicate that influenza virus coinfection occurs more often than previously reported and that it can lead to a worse disease outcome.

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Influenza Vaccine Effectiveness Among Children for the 2017–2018 Season

Journal of the Pediatric Infectious Diseases Society ◽

10.1093/jpids/piz077 ◽

2019 ◽

Vol 9 (4) ◽

pp. 468-473 ◽

Cited By ~ 2

Author(s):

Lauren N Powell ◽

Rodolfo E Bégué

Keyword(s):

Influenza Vaccine ◽

Influenza A ◽

Influenza Season ◽

Vaccine Effectiveness ◽

Influenza B ◽

Immunization Registry ◽

Previous Season ◽

Waning Immunity ◽

Small Benefit ◽

Susceptible Populations

Abstract Background The 2017–2018 influenza season was of high severity. Circulating influenza strains change periodically, making it important to determine vaccine effectiveness on an annual basis, especially for susceptible populations. The primary aim of our study was to estimate the effectiveness of the influenza vaccine among children. Secondary aims were to assess the effect of previous season vaccination and intraseasonal waning of immunity. Methods Children 6 months to 17 years of age tested for influenza during the 2017–2018 season were included. Clinical charts were reviewed, and immunization status was confirmed via the Louisiana Immunization Registry. Influenza vaccine effectiveness (IVE) was estimated in a test-negative design by comparing vaccination status of influenza-positive vs influenza-negative cases. Results A total of 3595 children were included, 26% of whom tested positive for influenza, mostly type A (79%); 15% had received an influenza vaccine prior to illness: 8% among the influenza-positive and 17% among influenza-negative cases (P <.0001). IVE for the 2017–2018 influenza season was 52% overall (95% confidence interval, 38%–62%), 49% for influenza A, and 60% for influenza B. While receiving current year (2017–2018) vaccine had the most effect, receiving the previous year (2016–2017) vaccine had a small benefit and no interference. We found no evidence of waning immunity of the vaccine for the 2017–2018 season. Conclusions IVE was moderate for children. Previous year vaccination had a small but significant benefit and there was no evidence of waning immunity in our cohort. Ongoing national and local surveillance is important to understand the benefit of influenza vaccination.

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Surveillance of influenza viruses isolated from travellers at Nagoya International Airport

Epidemiology and Infection ◽

10.1017/s0950268899003738 ◽

2000 ◽

Vol 124 (3) ◽

pp. 507-514 ◽

Cited By ~ 12

Author(s):

K. SATO ◽

T. MORISHITA ◽

E. NOBUSAWA ◽

Y. SUZUKI ◽

Y. MIYAZAKI ◽

...

Keyword(s):

Influenza A ◽

Respiratory Symptoms ◽

H1n1 Virus ◽

Influenza Season ◽

Influenza Viruses ◽

H3n2 Virus ◽

Influenza B ◽

International Airport ◽

Quarantine Station ◽

Virus Strains

In order to conduct a survey of influenza viruses entering Japan via travellers arriving by airplanes, gargle solutions were collected from passengers who reported to the quarantine station of Nagoya International Airport complaining of respiratory symptoms. From 504 samples collected between August 1996 and March 1999, 30 influenza virus strains were isolated. Twenty-eight of the isolates were influenza A (H3N2) viruses and two were influenza B viruses. No H1N1 virus was isolated. Among 28 isolates of H3N2 virus, 3 strains were obtained outside the influenza season. Nucleotide sequences of the haemagglutinin (HA) genes of these isolates along with those from domestic patients were analysed in order to determine the influence of imported influenza viruses by travellers on epidemics in Japan. From the phylogenetic and chronological aspects, the possibility was suggested in one case in 1997/8 and two in the 1998/9 season that imported virus by travellers may have influenced the domestic influenza epidemics.

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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.

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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.

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