scholarly journals Poor Immunogenicity, Not Vaccine Strain Egg Adaptation, May Explain the Low H3N2 Influenza Vaccine Effectiveness in 2012–2013

2018 ◽  
Vol 67 (3) ◽  
pp. 327-333 ◽  
Author(s):  
Sarah Cobey ◽  
Sigrid Gouma ◽  
Kaela Parkhouse ◽  
Benjamin S Chambers ◽  
Hildegund C Ertl ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Vaccine Strain ◽  
Vaccine Effectiveness ◽  
H3n2 Influenza

scholarly journals Successes and Failures of the Live-attenuated Influenza Vaccine: Can We Do Better?

2019 ◽  
Vol 70 (6) ◽  
pp. 1029-1037 ◽  
Author(s):  
Laura Matrajt ◽  
M Elizabeth Halloran ◽  
Rustom Antia
Keyword(s):  
Influenza Vaccine ◽  
Mathematical Models ◽  
Vaccine Strain ◽  
Influenza Season ◽  
Mechanistic Explanation ◽  
Vaccine Effectiveness ◽  
Challenge Strain ◽  
Influenza Strain ◽  
Live Attenuated Influenza Vaccine ◽  
The World

Abstract Background The effectiveness of the live-attenuated influenza vaccine (LAIV) can vary widely, ranging from 0% to 50%. The reasons for these discrepancies remain largely unclear. Methods We use mathematical models to explore how the efficacy of LAIV is affected by the degree of mismatch with the currently circulating influenza strain and interference with pre-existing immunity. The models incorporate 3 key antigenic distances: the distances between the vaccine strain, pre-existing immunity, and the challenge strain. Results Our models show that an LAIV that is matched with the currently circulating strain is likely to have only modest efficacy. Our results suggest that the efficacy of the vaccine would be increased (optimized) if, rather than being matched to the circulating strain, it is antigenically slightly further from pre-existing immunity than the circulating strain. The models also suggest 2 regimes in which LAIV that is matched to circulating strains may be protective: in children before they have built immunity to circulating strains and in response to novel strains (such as antigenic shifts) which are at substantial antigenic distance from previously circulating strains. We provide an explanation for the variation in vaccine effectiveness between studies and countries of vaccine effectiveness observed during the 2014–2015 influenza season. Conclusions LAIV is offered to children across the world; however, its effectiveness significantly varies between studies. Here, we propose a mechanistic explanation to understand these differences. We further propose a way to select the LAIV strain that would have a higher chance of being protective.

The Impact of Prior Season Vaccination on Subsequent Influenza Vaccine Effectiveness to Prevent Influenza-related Hospitalizations Over 4 Influenza Seasons in Canada

2018 ◽  
Vol 69 (6) ◽  
pp. 970-979 ◽  
Author(s):  
M K Nichols ◽  
M K Andrew ◽  
L Ye ◽  
T F Hatchette ◽  
A Ambrose ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Negative Impact ◽  
Conditional Logistic Regression ◽  
Vaccine Effectiveness ◽  
Influenza B ◽  
Current Season ◽  
Vaccination Recommendations ◽  
Vaccine Impact ◽  
H3n2 Influenza ◽  
The Impact

Abstract Background Recent studies have demonstrated the possibility of negative associations between prior influenza vaccines and subsequent influenza vaccine effectiveness (VE), depending on season and strain. We investigated this association over 4 consecutive influenza seasons (2011–2012 through 2014–2015) in Canada. Methods Using a matched test-negative design, laboratory-confirmed influenza cases and matched test-negative controls admitted to hospitals were enrolled. Patients were stratified into 4 groups according to influenza vaccine history (not vaccinated current and prior season [referent], vaccinated prior season only, vaccinated current season only, and vaccinated both current and prior season). Conditional logistic regression was used to estimate VE; prior vaccine impact was assessed each season for overall effect and effect stratified by age (<65 years, ≥65 years) and type/subtype (A/H1N1, A/H3N2, influenza B). Results Overall, mainly nonsignificant associations were observed. Trends of nonsignificant decreased VE among patients repeatedly vaccinated in both prior and current season relative to the current season only were observed in the A/H3N2-dominant seasons of 2012–2013 and 2014–2015. Conversely, in 2011–2012, during which B viruses circulated, and in 2013–2014, when A/H1N1 circulated, being vaccinated in both seasons tended to result in a high VE in the current season against the dominant circulating subtype. Conclusions Prior vaccine impact on subsequent VE among Canadian inpatients was mainly nonsignificant. Even in circumstances where we observed a trend of negative impact, being repeatedly vaccinated was still more effective than not receiving the current season’s vaccine. These findings favor continuation of annual influenza vaccination recommendations, particularly in older adults. Clinical Trials Registration NCT01517191.

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 Low 2012–13 Influenza Vaccine Effectiveness Associated with Mutation in the Egg-Adapted H3N2 Vaccine Strain Not Antigenic Drift in Circulating Viruses

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e92153 ◽  
Author(s):  
Danuta M. Skowronski ◽  
Naveed Z. Janjua ◽  
Gaston De Serres ◽  
Suzana Sabaiduc ◽  
Alireza Eshaghi ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Vaccine Strain ◽  
Vaccine Effectiveness ◽  
Antigenic Drift ◽  
H3n2 Vaccine

scholarly journals Waning Vaccine Effectiveness Against Influenza-Associated Hospitalizations Among Adults, 2015–2016 to 2018–2019, United States Hospitalized Adult Influenza Vaccine Effectiveness Network

2021 ◽  
Author(s):  
Jill M Ferdinands ◽  
Manjusha Gaglani ◽  
Emily T Martin ◽  
Arnold S Monto ◽  
Donald Middleton ◽  
...  
Keyword(s):  
United States ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Vaccine Effectiveness ◽  
Influenza B ◽  
Influenza A H1n1 ◽  
H3n2 Influenza

Abstract We observed decreased effectiveness of influenza vaccine with increasing time since vaccination for prevention of influenza A(H3N2), influenza A(H1N1)pdm09, and influenza B/Yamagata–associated hospitalizations among adults. Maximum vaccine effectiveness (VE) was observed shortly after vaccination, followed by an absolute decline in VE of about 8%–9% per month postvaccination.

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