Influenza Vaccine Effectiveness in the 2014–2015 Season for Children 2–17 Years by Vaccine Type: US Influenza Vaccine Effectiveness Network

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.

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Effectiveness of influenza vaccination in preventing hospitalisation due to influenza in children: a systematic review and meta-analysis

Clinical Infectious Diseases ◽

10.1093/cid/ciab270 ◽

2021 ◽

Author(s):

Nicki L Boddington ◽

Isabelle Pearson ◽

Heather Whitaker ◽

Punam Mangtani ◽

Richard G Pebody

Keyword(s):

Systematic Review ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Random Effects ◽

Influenza A ◽

Influenza Infection ◽

Meta Analysis ◽

Vaccine Effectiveness ◽

Vaccine Type ◽

Inactivated Vaccines

Abstract This systematic review assesses the literature for estimates of influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza-associated hospitalisation in children. Studies of any design to 08 June 2020 were included if the outcome was hospitalisation, participants were 17 years old or less and influenza infection was laboratory-confirmed. A random-effects meta-analysis of 37 studies that used a test-negative design gave a pooled seasonal IVE against hospitalisation of 53.3% (47.2-58.8) for any influenza. IVE was higher against influenza A/H1N1pdm09 (68.7%, 56.9-77.2) and lowest against influenza A/H3N2 (35.8%, 23.4-46.3). Estimates by vaccine type ranged from 44.3% (30.1-55.7) for LAIV to 68.9% (53.6-79.2) for inactivated vaccines. IVE estimates were higher in seasons when the circulating influenza strains were antigenically matched to vaccine strains (59.3%, 48.3-68.0). Influenza vaccination gives moderate overall protection against influenza-associated hospitalisation in children supporting annual vaccination. IVE varies by influenza subtype and vaccine type.

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Effectiveness of 2 Influenza Vaccines in Nationwide Cohorts of Finnish 2-Year-Old Children in the Seasons 2015–2016 Through 2017–2018

Clinical Infectious Diseases ◽

10.1093/cid/ciaa050 ◽

2020 ◽

Vol 71 (8) ◽

pp. e255-e261

Author(s):

Ulrike Baum ◽

Sangita Kulathinal ◽

Kari Auranen ◽

Hanna Nohynek

Keyword(s):

Influenza Vaccine ◽

Virus Type ◽

Real Life ◽

Vaccine Effectiveness ◽

Influenza Vaccines ◽

Type B ◽

Live Attenuated Influenza Vaccine ◽

Vaccine Type ◽

Decision Making Processes ◽

Study Population

Abstract Background From 2015–2016 through 2017–2018, injectable, trivalent inactivated influenza vaccines (IIV3) and a nasal spray, tetravalent live-attenuated influenza vaccine (LAIV4) were used in parallel in Finland. To understand how well vaccination with each vaccine type protected children against influenza under real-life conditions, vaccine effectiveness in 2-year-olds was estimated for all 3 seasons. Methods Each season, a nationwide register-based cohort study was conducted. The study population comprised 60 088, 60 860, and 60 345 children in 2015–2016, 2016–2017, and 2017–2018, respectively. Laboratory-confirmed influenza was the study outcome. Seasonal influenza vaccination with either LAIV4 or IIV3 was the time-dependent exposure of interest. Vaccine effectiveness was defined as 1 minus the hazard ratio comparing vaccinated with unvaccinated children. Results From 2015–2016 through 2017–2018, the effectiveness of LAIV4 against influenza of any virus type was estimated at 54.2% (95% confidence interval, 32.2–69.0%), 20.3% (−12.7%, 43.6%), and 30.5% (10.9–45.9%); the corresponding effectiveness of IIV3 was 77.2% (48.9–89.8%), 24.5% (−29.8%, 56.1%), and −20.1% (−61.5%, 10.7%). Neither influenza vaccine clearly excelled in protecting children. The LAIV4 effectiveness against type B was greater than against type A and greater than the IIV3 effectiveness against type B. Conclusions To understand how influenza vaccines could be improved, vaccine effectiveness must be analyzed by vaccine and virus type. Effectiveness estimates also expressing overall protection levels are needed to guide individual and programmatic decision-making processes. Supported by this analysis, the vaccination program in Finland now recommends LAIV4 and injectable, tetravalent inactivated influenza vaccines replacing IIV3.

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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.

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Influenza Vaccine Effectiveness Against 2009 Pandemic Influenza A(H1N1) Virus Differed by Vaccine Type During 2013–2014 in the United States

The Journal of Infectious Diseases ◽

10.1093/infdis/jiv577 ◽

2016 ◽

Vol 213 (10) ◽

pp. 1546-1556 ◽

Cited By ~ 113

Author(s):

Manjusha Gaglani ◽

Jessica Pruszynski ◽

Kempapura Murthy ◽

Lydia Clipper ◽

Anne Robertson ◽

...

Keyword(s):

United States ◽

Influenza Vaccine ◽

Pandemic Influenza ◽

Influenza A ◽

H1n1 Virus ◽

The United States ◽

Vaccine Effectiveness ◽

Influenza A H1n1 ◽

Vaccine Type

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Influenza vaccine effectiveness in Italy: Age, subtype-specific and vaccine type estimates 2014/15 season

Vaccine ◽

10.1016/j.vaccine.2016.04.072 ◽

2016 ◽

Vol 34 (27) ◽

pp. 3102-3108 ◽

Cited By ~ 11

Author(s):

Caterina Rizzo ◽

Antonino Bella ◽

Valeria Alfonsi ◽

Simona Puzelli ◽

Anna Pina Palmieri ◽

...

Keyword(s):

Influenza Vaccine ◽

Vaccine Effectiveness ◽

Vaccine Type

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2757. Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD (PAIVED): Immunogenicity Sub-Study

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.2434 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S971-S972

Author(s):

Rhonda Colombo ◽

Stephanie Richard ◽

Christina Schofield ◽

Limone Collins ◽

Anuradha Ganesan ◽

...

Keyword(s):

Influenza Vaccine ◽

Vaccine Effectiveness ◽

Vaccine Uptake ◽

Buccal Swab ◽

Study Cohort ◽

Blood Draw ◽

Physically Active ◽

Vaccine Type ◽

Study Participants ◽

Pragmatic Assessment

Abstract Background Despite greater than 90% of US active duty (AD) military personnel receiving influenza vaccination annually, vaccine effectiveness (VE) among AD members has been substantially lower than in groups with less vaccine uptake. The substrate used in vaccine production may impact immunogenicity and thus VE. The PAIVED study is investigating VE of 3 different influenza vaccine formulations; a sub-study assesses immunogenicity. This analysis compares demographic characteristics and influenza-like illness (ILI) experience among main and sub-study participants for the first year of PAIVED. Methods During the 2018–2019 influenza season, PAIVED enrolled participants at 5 military medical centers, recruiting sub-study subjects from the main cohort excluding marine recruits. All participants were randomized (1:1:1) to receive either egg-based, cell-culture based or recombinant influenza vaccine. At enrollment, participants provided key demographic and behavioral data. Weekly surveillance for ILI symptoms was performed electronically. Sub-study volunteers underwent an additional blood draw prior to and at 21–35 days post vaccination ± an optional buccal swab. Results 200 (23.5%) of 852 non-recruit PAIVED participants enrolled in the immunogenicity sub-study. Similar to the main cohort, 46% of sub-study volunteers were female, 85% were physically active, and 6% smoked tobacco. Sub-study participants were younger (47 ± 16 years vs. 51 ± 17 years, P = 0.004) and more likely to be AD (34% vs. 22%, P = 0.001). Although 70% of both groups identified as White, the percent African American (20% sub-study; 13% main), Asian (3%; 7%), multi-racial (2%; 5%), and unknown (6%; 4%) differed (P = 0.02). More sub-study participants developed an ILI (19% vs. 12%, P = 0.02). Conclusion The convenience sampling method used for recruitment into the sub-study was effective. The younger age and higher AD status in the sub-study group may be informative for evaluation of military readiness issues. The greater incidence of ILI in the sub-study increases the chance differences in immune response by vaccine type may be interpretable in the context of circulating influenza strains. Targeted efforts to enhance recruitment of a racially diverse sub-study cohort may be warranted. Disclosures All authors: No reported disclosures.

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