scholarly journals Interim estimates of 2015/16 vaccine effectiveness against influenza A(H1N1)pdm09, Canada, February 2016

2016 ◽  
Vol 21 (11) ◽  
Author(s):  
Catharine Chambers ◽  
Danuta M Skowronski ◽  
Suzana Sabaiduc ◽  
Anne Luise Winter ◽  
James A Dickinson ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Northern Hemisphere ◽  
Influenza A ◽  
Vaccine Effectiveness ◽  
Genetic Evolution ◽  
Significant Protection ◽  
Surveillance Network ◽  
Potential Gain ◽  
Influenza A H1n1

Using a test-negative design, the Canadian Sentinel Practitioner Surveillance Network (SPSN) assessed interim 2015/16 vaccine effectiveness (VE) against influenza A(H1N1)pdm09 viruses. Adjusted VE showed significant protection of 64% (95% confidence interval (CI): 44–77%) overall and 56% (95%CI: 26–73%) for adults between 20 and 64 years-old against medically attended, laboratory-confirmed A(H1N1)pdm09 illness. Among the 67 A(H1N1)pdm09-positive specimens that were successfully sequenced, 62 (> 90%) belonged to the emerging genetic 6B.1 subclade, defined by S162N (potential gain of glycosylation) and I216T mutations in the haemagglutinin protein. Findings from the Canadian SPSN indicate that the 2015/16 northern hemisphere vaccine provided significant protection against A(H1N1)pdm09 illness despite genetic evolution in circulating viruses.

scholarly journals Interim estimates of 2018/19 vaccine effectiveness against influenza A(H1N1)pdm09, Canada, January 2019

2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Danuta M Skowronski ◽  
Siobhan Leir ◽  
Suzana Sabaiduc ◽  
Michelle Murti ◽  
James A Dickinson ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Young Children ◽  
Confidence Interval ◽  
Influenza A ◽  
Age Groups ◽  
Vaccine Effectiveness ◽  
Surveillance Network ◽  
Vaccine Protection ◽  
Influenza A H1n1

Using a test-negative design, the Canadian Sentinel Practitioner Surveillance Network assessed interim 2018/19 vaccine effectiveness (VE) against predominant influenza A(H1N1)pdm09 viruses. Adjusted VE was 72% (95% confidence interval: 60 to 81) against medically attended, laboratory-confirmed influenza A(H1N1)pdm09 illness. This substantial vaccine protection was observed in all age groups, notably young children who appeared to be disproportionately affected. Sequence analysis identified heterogeneity in emerging clade 6B.1 viruses but no dominant drift variant.

scholarly journals Influenza Vaccine Effectiveness and Waning Effect in Hospitalized Older Adults. Valencia Region, Spain, 2018/2019 Season

2021 ◽  
Vol 18 (3) ◽  
pp. 1129
Author(s):  
Ainara Mira-Iglesias ◽  
F. Xavier López-Labrador ◽  
Javier García-Rubio ◽  
Beatriz Mengual-Chuliá ◽  
Miguel Tortajada-Girbés ◽  
...  
Keyword(s):  
Older Adults ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Vaccine Effectiveness ◽  
Surveillance Network ◽  
Adjuvanted Vaccine ◽  
Clinical Registries ◽  
Populations At Risk ◽  
Influenza A H1n1 ◽  
Hospitalized Older Adults

Influenza vaccination is annually recommended for specific populations at risk, such as older adults. We estimated the 2018/2019 influenza vaccine effectiveness (IVE) overall, by influenza subtype, type of vaccine, and by time elapsed since vaccination among subjects 65 years old or over in a multicenter prospective study in the Valencia Hospital Surveillance Network for the Study of Influenza and other Respiratory Viruses (VAHNSI, Spain). Information about potential confounders was obtained from clinical registries and/or by interviewing patients and vaccination details were only ascertained by registries. A test-negative design was performed in order to estimate IVE. As a result, IVE was estimated at 46% (95% confidence interval (CI): (16%, 66%)), 41% (95% CI: (−34%, 74%)), and 45% (95% CI: (7%, 67%)) against overall influenza, A(H1N1)pdm09 and A(H3N2), respectively. An intra-seasonal not relevant waning effect was detected. The IVE for the adjuvanted vaccine in ≥75 years old was 45% (2%, 69%) and for the non-adjuvanted vaccine in 65–74 years old was 59% (−16%, 86%). Thus, our data revealed moderate vaccine effectiveness against influenza A(H3N2) and not significant against A(H1N1)pdm09. Significant protection was conferred by the adjuvanted vaccine to patients ≥75 years old. Moreover, an intra-seasonal not relevant waning effect was detected, and a not significant IVE decreasing trend was observed over time.

scholarly journals Interim estimates of 2019/20 vaccine effectiveness during early-season co-circulation of influenza A and B viruses, Canada, February 2020

2020 ◽  
Vol 25 (7) ◽  
Author(s):  
Danuta M Skowronski ◽  
Macy Zou ◽  
Suzana Sabaiduc ◽  
Michelle Murti ◽  
Romy Olsha ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Vaccine Effectiveness ◽  
Influenza B ◽  
Surveillance Network ◽  
Early Season ◽  
Influenza Illness

Interim results from Canada's Sentinel Practitioner Surveillance Network show that during a season characterised by early co-circulation of influenza A and B viruses, the 2019/20 influenza vaccine has provided substantial protection against medically-attended influenza illness. Adjusted VE overall was 58% (95% confidence interval (CI): 47 to 66): 44% (95% CI: 26 to 58) for A(H1N1)pdm09, 62% (95% CI: 37 to 77) for A(H3N2) and 69% (95% CI: 57 to 77) for influenza B viruses, predominantly B/Victoria lineage.

scholarly journals Influenza vaccine effectiveness against influenza A in children based on the results of various rapid influenza tests in the 2018/19 season

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249005
Author(s):  
Masayoshi Shinjoh ◽  
Norio Sugaya ◽  
Yoshio Yamaguchi ◽  
Ichiro Ookawara ◽  
Yuji Nakata ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Influenza Vaccine ◽  
Diagnostic Tests ◽  
Influenza A ◽  
Control Design ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Test Results ◽  
Negative Case ◽  
Influenza A H1n1

During influenza epidemics, Japanese clinicians routinely conduct rapid influenza diagnostic tests (RIDTs) in patients with influenza-like illness, and patients with positive test results are treated with anti-influenza drugs within 48 h after the onset of illness. We assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children (6 months–15 years old, N = 4243), using a test-negative case-control design based on the results of RIDTs in the 2018/19 season. The VE against influenza A(H1N1)pdm and A(H3N2) was analyzed separately using an RIDT kit specifically for detecting A(H1N1)pdm09. The adjusted VE against combined influenza A (H1N1pdm and H3N2) and against A(H1N1)pdm09 was 39% (95% confidence interval [CI], 30%–46%) and 74% (95% CI, 39%–89%), respectively. By contrast, the VE against non-A(H1N1)pdm09 influenza A (presumed to be H3N2) was very low at 7%. The adjusted VE for preventing hospitalization was 56% (95% CI, 16%–77%) against influenza A. The VE against A(H1N1)pdm09 was consistently high in our studies. By contrast, the VE against A(H3N2) was low not only in adults but also in children in the 2018/19 season.

scholarly journals Interim estimates of 2013/14 vaccine effectiveness against influenza A(H1N1)pdm09 from Canada’s sentinel surveillance network, January 2014

2014 ◽  
Vol 19 (5) ◽  
Author(s):  
D M Skowronski ◽  
C Chambers ◽  
S Sabaiduc ◽  
G De Serres ◽  
J A Dickinson ◽  
...  
Keyword(s):  
Influenza A ◽  
Vaccine Effectiveness ◽  
Sentinel Surveillance ◽  
Surveillance Network ◽  
Binary File ◽  
Influenza A H1n1

Binary file ES_Abstracts_Final_ECDC.txt matches

scholarly journals Interim estimates of 2016/17 vaccine effectiveness against influenza A(H3N2), Canada, January 2017

2017 ◽  
Vol 22 (6) ◽  
Author(s):  
Danuta M Skowronski ◽  
Catharine Chambers ◽  
Suzana Sabaiduc ◽  
James A Dickinson ◽  
Anne-Luise Winter ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Confidence Interval ◽  
Influenza Vaccine ◽  
Vaccine Strain ◽  
Influenza A ◽  
Vaccine Effectiveness ◽  
Surveillance Network ◽  
Potential Vaccine ◽  
Substantial Heterogeneity ◽  
Over Time

Using a test-negative design, the Canadian Sentinel Practitioner Surveillance Network (SPSN) assessed interim 2016/17 influenza vaccine effectiveness (VE) against dominant influenza A(H3N2) viruses considered antigenically matched to the clade 3C.2a vaccine strain. Sequence analysis revealed substantial heterogeneity in emerging 3C.2a1 variants by province and over time. Adjusted VE was 42% (95% confidence interval: 18–59%) overall, with variation by province. Interim virological and VE findings reported here warrant further investigation to inform potential vaccine reformulation.

scholarly journals Children under 10 years of age were more affected by the 2018/19 influenza A(H1N1)pdm09 epidemic in Canada: ‎possible cohort effect following the 2009 influenza pandemic

2019 ◽  
Vol 24 (15) ◽  
Author(s):  
Danuta M Skowronski ◽  
Siobhan Leir ◽  
Gaston De Serres ◽  
Michelle Murti ◽  
James A Dickinson ◽  
...  
Keyword(s):  
General Population ◽  
Influenza A ◽  
Influenza Pandemic ◽  
Age Distribution ◽  
Cohort Effect ◽  
Surveillance Network ◽  
Medical Visits ◽  
Influenza A H1n1 ◽  
2009 Influenza Pandemic ◽  
Negative Controls

Introduction Findings from the community-based Canadian Sentinel Practitioner Surveillance Network (SPSN) suggest children were more affected by the 2018/19 influenza A(H1N1)pdm09 epidemic. Aim To compare the age distribution of A(H1N1)pdm09 cases in 2018/19 to prior seasonal influenza epidemics in Canada. Methods The age distribution of unvaccinated influenza A(H1N1)pdm09 cases and test-negative controls were compared across A(H1N1)pdm09-dominant epidemics in 2018/19, 2015/16 and 2013/14 and with the general population of SPSN provinces. Similar comparisons were undertaken for influenza A(H3N2)-dominant epidemics. Results In 2018/19, more influenza A(H1N1)pdm09 cases were under 10 years old than controls (29% vs 16%; p < 0.001). In particular, children aged 5–9 years comprised 14% of cases, greater than their contribution to controls (4%) or the general population (5%) and at least twice their contribution in 2015/16 (7%; p < 0.001) or 2013/14 (5%; p < 0.001). Conversely, children aged 10–19 years (11% of the population) were under-represented among A(H1N1)pdm09 cases versus controls in 2018/19 (7% vs 12%; p < 0.001), 2015/16 (7% vs 13%; p < 0.001) and 2013/14 (9% vs 12%; p = 0.12). Conclusion Children under 10 years old contributed more to outpatient A(H1N1)pdm09 medical visits in 2018/19 than prior seasonal epidemics in Canada. In 2018/19, all children under 10 years old were born after the 2009 A(H1N1)pdm09 pandemic and therefore lacked pandemic-induced immunity. In addition, more than half those born after 2009 now attend school (i.e. 5–9-year-olds), a socio-behavioural context that may enhance transmission and did not apply during prior A(H1N1)pdm09 epidemics.

scholarly journals Origins of the new influenza A(H1N1) virus: time to take action

2009 ◽  
Vol 14 (22) ◽  
Author(s):  
G M Nava ◽  
M S Attene-Ramos ◽  
J K Ang ◽  
M Escorcia
Keyword(s):  
Influenza A ◽  
H1n1 Virus ◽  
Phylogenetic Analyses ◽  
Protein Sequences ◽  
Interspecies Transmission ◽  
Genetic Evolution ◽  
Protein Homology ◽  
Influenza A H1n1 ◽  
Insight Into

To gain insight into the possible origins of the 2009 outbreak of new influenza A(H1N1), we performed two independent analyses of genetic evolution of the new influenza A(H1N1) virus. Firstly, protein homology analyses of more than 400 sequences revealed that this virus most likely evolved from recent swine viruses. Secondly, phylogenetic analyses of 5,214 protein sequences of influenza A(H1N1) viruses (avian, swine and human) circulating in North America for the last two decades (from 1989 to 2009) indicated that the new influenza A(H1N1) virus possesses a distinctive evolutionary trait (genetic distinctness). This appears to be a particular characteristic in pig-human interspecies transmission of influenza A. Thus these analyses contribute to the evidence of the role of pig populations as “mixing vessels” for influenza A(H1N1) viruses.

scholarly journals Should Sex Be Considered an Effect Modifier in the Evaluation of Influenza Vaccine Effectiveness?

2018 ◽  
Vol 5 (9) ◽  
Author(s):  
Catharine Chambers ◽  
Danuta M Skowronski ◽  
Caren Rose ◽  
Gaston De Serres ◽  
Anne-Luise Winter ◽  
...  
Keyword(s):  
Older Adults ◽  
Sex Differences ◽  
Confidence Interval ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Vaccine Effectiveness ◽  
Absolute Difference ◽  
Effect Modifier ◽  
Potential Interactions

Abstract We investigated sex as a potential modifier of influenza vaccine effectiveness (VE) between 2010–2011 and 2016–2017 in Canada. Overall VE was 49% (95% confidence interval [CI], 43% to 55%) for females and 38% (95% CI, 28% to 46%) for males (absolute difference [AD], 11%; P = .03). Sex differences were greatest for influenza A(H3N2) (AD, 17%; P = .07) and B(Victoria) (AD, 20%; P = .08) compared with A(H1N1)pdm09 (AD, 10%; P = .19) or B(Yamagata) (AD, –3%; P = .68). They were also more pronounced in older adults ≥50 years (AD, 19%; P = .03) compared with those &lt;20 years (AD, 4%; P = .74) or 20–49 years (AD, –1%; P = .90) but with variation by subtype/lineage. More definitive investigations of VE by sex and age are warranted to elucidate these potential interactions.

Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09

2014 ◽  
Vol 63 (12) ◽  
pp. 1626-1637 ◽  
Author(s):  
Mara L. Russo ◽  
Andrea V. Pontoriero ◽  
Estefania Benedetti ◽  
Andrea Czech ◽  
Martin Avaro ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Influenza A ◽  
Vaccine Virus ◽  
Influenza Viruses ◽  
World Health ◽  
Influenza Surveillance ◽  
Human Influenza ◽  
Surveillance Network ◽  
Influenza A H1n1 ◽  
Health Organization

This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed during the study period. The virological surveillance showed that the majority of the circulating strains during the study period were antigenically related to the corresponding Southern Hemisphere vaccine strains except for the 2012 A(H3N2) viruses.

Sign in / Sign up

Export Citation Format

Share Document