scholarly journals Relative Effectiveness of Influenza Vaccines Among the United States Elderly, 2018–2019

2020 ◽  
Vol 222 (2) ◽  
pp. 278-287 ◽  
Author(s):  
Hector S Izurieta ◽  
Yoganand Chillarige ◽  
Jeffrey Kelman ◽  
Yuqin Wei ◽  
Yun Lu ◽  
...  

Abstract Background Studies among individuals ages ≥65 years have found a moderately higher relative vaccine effectiveness (RVE) for the high-dose (HD) influenza vaccine compared with standard-dose (SD) products for most seasons. Studies during the A(H3N2)-dominated 2017–2018 season showed slightly higher RVE for the cell-cultured vaccine compared with SD egg-based vaccines. We investigated the RVE of influenza vaccines among Medicare beneficiaries ages ≥65 years during the 2018–2019 season. Methods This is a retrospective cohort study using inverse probability of treatment weighting and Poisson regression to evaluate RVE in preventing influenza hospital encounters. Results Among 12 777 214 beneficiaries, the egg-based adjuvanted (RVE, 7.7%; 95% confidence interval [CI], 3.9%–11.4%) and HD (RVE, 4.9%; 95% CI, 1.7%–8.1%) vaccines were marginally more effective than the egg-based quadrivalent vaccines. The cell-cultured quadrivalent vaccine was not significantly more effective than the egg-based quadrivalent vaccine (RVE, 2.5%; 95% CI, −2.4% to 7.3%). Conclusions We did not find major effectiveness differences between licensed vaccines used among the elderly during the 2018–2019 season. Consistent with prior research, we found that the egg-based adjuvanted and HD vaccines were slightly more effective than the egg-based quadrivalent vaccines.

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Marina Amaral de Avila Machado ◽  
Cristiano S. Moura ◽  
Michal Abrahamowicz ◽  
Brian J. Ward ◽  
Louise Pilote ◽  
...  

AbstractInfluenza immunization protects seniors against influenza and its potentially serious complications. It is uncertain whether standard-dose (SD) quadrivalent vaccine offers better protection over other formulations in the elderly. In this study, we compared the effectiveness of SD-trivalent, high-dose (HD) trivalent, SD-quadrivalent, and adjuvanted trivalent vaccines in seniors (≥65 years) in a real-world setting. We selected over 200,000 individuals in each of 6 influenza seasons from 2012 to 2018 using MarketScan® databases. The two outcomes were hospitalization or emergency room (ER) visit due to (1) influenza or (2) pneumonia. Here, SD-quadrivalent was associated with higher risk of influenza-related hospitalization/ER visit (adjusted hazard ratio (aHR) 1.14 and 95% confidence interval (95% CI) 1.05–1.24) and of pneumonia-related hospitalization/ER visit (aHR 1.04 and 95% CI 1.01–1.07) vs. HD-trivalent. SD-trivalent followed similar trends compared to HD-trivalent (aHR 1.16 and 95% CI 1.06–1.27 for hospitalized/ER visit influenza; aHR 1.07 and 95% CI 1.05–1.10 for hospitalized/ER visit pneumonia). We could not demonstrate risk differences between SD vaccine formulations and between adjuvanted trivalent and one of the other three vaccines. Risk estimates slightly varied across seasons. These findings suggest that SD vaccine formulations vs. HD-trivalent were associated with higher risk of hospitalization/ER visit for influenza and pneumonia in seniors.


Author(s):  
Hector S Izurieta ◽  
Michael Lu ◽  
Jeffrey Kelman ◽  
Yun Lu ◽  
Arnstein Lindaas ◽  
...  

Abstract Background Around 50,000 influenza-associated deaths occur annually in the U.S., overwhelmingly among individuals ages >65 years. Although vaccination is the primary prevention tool, investigations have shown low vaccine effectiveness (VE) in recent years, particularly among the elderly. We analyzed the relative VE (RVE) of all influenza vaccines among Medicare beneficiaries ages >65 years to prevent influenza hospital encounters during the 2019-20 season. Methods Retrospective cohort study using Poisson regression and inverse probability of treatment weighting (IPTW). Exposures included egg-based high-dose trivalent (HD-IIV3), egg-based adjuvanted trivalent (aIIV3), egg-based standard dose (SD) quadrivalent (IIV4), cell-based SD quadrivalent (cIIV4), and recombinant quadrivalent (RIV4) influenza vaccines. Results We studied 12.7 million vaccinated beneficiaries. Following IPTW, cohorts were well balanced for all covariates and health-seeking behavior indicators. In the adjusted analysis, RIV4 (RVE 13.3%, 95% CI 7.4%, 18.9%), aIIV3 (RVE 8.2%, 95% CI 4.2%, 12.0%), and HD-IIV3 (RVE 6.8%, 95% CI 3.3%, 10.1%) were significantly more effective in preventing hospital encounters than the reference egg-based SD IIV4, while cIIV4 was not significantly more effective than IIV4 (RVE 2.8%, 95% CI -2.8%, 8.2%). Our results were consistent across all analyses. Conclusions In this influenza B-Victoria and A(H1N1)-dominated season, RIV4 was moderately more effective than other vaccines, while the HD-IIV3 and aIIV3 were more effective than the IIV4 vaccines, highlighting the contributions of antigen amount and adjuvant use to VE. Egg adaptation likely did not substantially affect our RVE evaluation. Our findings, specific to the 2019-20 season, should be evaluated in other studies using virological case confirmation.


2018 ◽  
Vol 220 (8) ◽  
pp. 1255-1264 ◽  
Author(s):  
Hector S Izurieta ◽  
Yoganand Chillarige ◽  
Jeffrey Kelman ◽  
Yuqin Wei ◽  
Yun Lu ◽  
...  

Abstract Background The low influenza vaccine effectiveness (VE) observed during the A(H3N2)-dominated 2017–2018 season may be due to vaccine virus adaptation to growth in eggs. We compared the effectiveness of cell-cultured and egg-based vaccines among Medicare beneficiaries. Methods Retrospective cohort study on Medicare beneficiaries aged ≥65 years who received an influenza vaccine (cell-cultured, egg-based quadrivalent; egg-based high-dose, adjuvanted, or standard-dose trivalent) during the 2017–2018 season. We used Poisson regression to evaluate relative VE (RVE) in preventing influenza-related hospital encounters. Results Of >13 million beneficiaries, RVE for cell-cultured vaccines relative to egg-based quadrivalent vaccines was 10% (95% confidence interval [CI], 7%–13%). In a midseason interim analysis, this estimate was 16.5% (95% CI, 10.3%–22.2%). In a 5-way comparison, cell-cultured (RVE, 11%; 95% CI, 8%–14%) and egg-based high-dose (RVE, 9%; 95% CI, 7%–11%) vaccines were more effective than egg-based quadrivalent vaccines. Conclusions The modest VE difference between cell-cultured and egg-based vaccines only partially explains the low overall VE reported by the Centers for Disease Control and Prevention, suggesting that egg adaptation was not the main contributor to the low VE found among individuals aged ≥65 years. The midseason interim analysis we performed demonstrates that our methods can be used to evaluate VE actively during the influenza season.


2019 ◽  
Vol 220 (9) ◽  
pp. 1511-1520 ◽  
Author(s):  
Yun Lu ◽  
Yoganand Chillarige ◽  
Hector S Izurieta ◽  
Yuqin Wei ◽  
Wenjie Xu ◽  
...  

AbstractBackgroundStudies have found that the high-dose influenza vaccine has a higher relative vaccine effectiveness (RVE) versus standard-dose vaccines in some seasons. We evaluated the effect of age on the RVE of high-dose versus standard-dose influenza vaccines among Medicare beneficiaries.MethodsA 6-season retrospective cohort study from 2012 to 2018 among Medicare beneficiaries aged ≥65 years was performed. Poisson regression was used to evaluate the effect of age on the RVE of high-dose versus standard-dose influenza vaccines in preventing influenza-related hospitalizations.ResultsThe study included >19 million vaccinated beneficiaries in a community pharmacy setting. The Poisson models indicated a slightly increasing trend in RVE with age in all seasons. The high-dose vaccine was more effective than standard-dose vaccines in preventing influenza-related hospital encounters (ie, influenza-related inpatient stays and emergency department visits) in the 2012–2013 (RVE, 23.1%; 95% confidence interval [CI], 17.6%–28.3%), 2013–2014 (RVE, 15.3%; 95% CI, 7.8%–22.3%), 2014–2015 (RVE, 8.9%; 95% CI, 5.6%–12.1%), and 2016–2017 (RVE, 12.6%; 95% CI, 6.3%–18.4%) seasons and was at least as effective in all other seasons. We also found that the high-dose vaccine was consistently more effective than standard-dose vaccines across all seasons for people aged ≥85 years. Similar trends were observed for influenza-related inpatient stays.ConclusionsThe RVE of high-dose versus standard-dose influenza vaccines increases with age.


Vaccine ◽  
2019 ◽  
Vol 37 (11) ◽  
pp. 1484-1490 ◽  
Author(s):  
Yinong Young-Xu ◽  
Julia Thornton Snider ◽  
Robertus van Aalst ◽  
Salaheddin M. Mahmud ◽  
Edward W. Thommes ◽  
...  

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S764-S764 ◽  
Author(s):  
Lee-Jah Chang ◽  
Ya Meng ◽  
Helene Janosczyk ◽  
Victoria Landolfi ◽  
H Keipp Talbot ◽  
...  

Abstract Background Older adults (≥65 years of age) remain at increased risk of influenza because they do not respond to standard dose influenza vaccines as well as younger adults. A high dose, inactivated trivalent influenza vaccine, IIV3-HD, containing four times the antigen content (60 µg hemagglutinin per influenza strain) of standard-dose influenza vaccines has been available in the United States since 2010. Two distinct B influenza lineages (Victoria and Yamagata) have co-circulated for over a decade, making it difficult to predict which will predominate the next season. IIV4-HD has been developed to address the frequent influenza B strain mismatches by incorporating a strain from each B lineage. This pivotal Phase III study evaluated the safety and immunogenicity of IIV4-HD as compared with two IIV3-HD vaccines. Method A randomized, modified double-blind, multicenter study (NCT03282240) was conducted in 2670 healthy subjects in the United States, who were randomly assigned to receive IIV4-HD, a licensed IIV3-HD, or an IIV3-HD with the alternate B influenza strain. Using the hemagglutinin inhibition (HAI) assay at baseline and 28 days after vaccination, post-vaccination geometric mean titers and seroconversion rates were measured. Safety data were collected through 6 months post-vaccination. Result IIV4-HD was noninferior to the licensed IIV3-HD and the investigational IIV3-HD (containing the alternate B strain) for all four influenza strains as assessed by HAI GMTs and seroconversion rates. Moreover, IIV4-HD induced a superior immune response (HAI GMTs and seroconversion rates) compared with the immune response induced by the IIV3-HD that does not contain the corresponding B strain. Reactogenicity profiles were comparable across all study groups. Most unsolicited adverse events were of Grade 1 or Grade 2 intensity. One serious adverse event considered related by the Investigator was reported in the IIV4-HD group. Conclusion Vaccination of adults 65 years of age and older with IIV4-HD was found to be noninferior to two IIV3-HD vaccines with a similar safety profile. The addition of a second B lineage strain does not adversely affect the safety or immunogenicity profile of IIV4-HD compared with IIV3-HD. Disclosures L. J. Chang, Sanofi Pasteur: Employee, Salary. Y. Meng, Sanofi Pasteur: Employee, Salary. H. Janosczyk, Sanofi Pasteur: Employee, Salary. V. Landolfi, Sanofi Pasteur: Employee, Salary. H. K. Talbot, Sanofi Pasteur: Investigator, Research grant. Gilead: Investigator, Research grant. MedImmune: Investigator, Research grant. Vaxinnate: Safety Board, none. Seqirus: Safety Board, none.


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S10-S10
Author(s):  
Joshua Doyle ◽  
Lauren Beacham ◽  
Elif Alyanak ◽  
Manjusha Gaglani ◽  
Emily T Martin ◽  
...  

Abstract Background Seasonal influenza causes substantial morbidity and mortality, and older adults are disproportionately affected. Newer vaccines have been developed for use in people 65 years and older, including a trivalent inactivated vaccine with a 4-fold higher dose of antigen (IIV-HD). In recent years, the use of IIV-HD has increased sufficiently to evaluate its effectiveness compared with standard-dose inactivated influenza vaccines (IIV-SD). Methods Hospitalized patients with acute respiratory illness were enrolled in an observational vaccine effectiveness study at 8 hospitals in 4 states participating in the United States Hospitalized Adult Influenza Vaccine Effectiveness Network during the 2015–2016 and 2016–2017 influenza seasons. Predominant influenza A virus subtypes were H1N1 and H3N2, respectively, during these seasons. All enrolled patients were tested for influenza virus with polymerase chain reaction. Receipt and type of influenza vaccine was determined from electronic records and chart review. Odds of laboratory-confirmed influenza were compared among vaccinated and unvaccinated patients. Relative odds of laboratory-confirmed influenza were determined for patients who received IIV-HD or IIV-SD, and adjusted for potential confounding variables via logistic regression. Results Among 1,744 enrolled patients aged ≥ 65 years, 1,105 (63%) were vaccinated; among those vaccinated, 621 (56%) received IIV-HD and 484 (44%) received IIV-SD. Overall, 315 (18%) tested positive for influenza, including 97 (6%) who received IIV-HD, 86 (5%) who received IIV-SD, and 132 (8%) who were unvaccinated. Controlling for age, race, sex, enrollment site, date of illness, index of comorbidity, and influenza season, the adjusted odds of influenza among patients vaccinated with IIV-HD vs. IIV-SD were 0.72 (P = 0.06, 95% CI: 0.52 to 1.01). Conclusion Comparison of high-dose vs. standard-dose vaccine effectiveness during 2 recent influenza seasons (1 H1N1 and 1 H3N2-predominant) suggested relative benefit (nonsignificant) of high-dose influenza vaccine in protecting against influenza-associated hospitalization among persons aged 65 years and older; additional years of data are needed to confirm this finding. Disclosures H. K. Talbot, sanofi pasteur: Investigator, Research grant. Gilead: Investigator, Research grant. MedImmune: Investigator, Research grant. Vaxinnate: Safety Board, none. Seqirus: Safety Board, none.


Author(s):  
Joshua D Doyle ◽  
Lauren Beacham ◽  
Emily T Martin ◽  
H Keipp Talbot ◽  
Arnold Monto ◽  
...  

Abstract Background Seasonal influenza causes substantial morbidity and mortality in older adults. High-dose inactivated influenza vaccine (HD-IIV), with increased antigen content compared to standard-dose influenza vaccines (SD-IIV), is licensed for use in people aged ≥65 years. We sought to evaluate the effectiveness of HD-IIV and SD-IIV for prevention of influenza-associated hospitalizations. Methods Hospitalized patients with acute respiratory illness were enrolled in an observational vaccine effectiveness study at 8 hospitals in the United States Hospitalized Adult Influenza Vaccine Effectiveness Network during the 2015–2016 and 2016–2017 influenza seasons. Enrolled patients were tested for influenza, and receipt of influenza vaccine by type was recorded. Effectiveness of SD-IIV and HD-IIV was estimated using a test-negative design (comparing odds of influenza among vaccinated and unvaccinated patients). Relative effectiveness of SD-IIV and HD-IIV was estimated using logistic regression. Results Among 1487 enrolled patients aged ≥65 years, 1107 (74%) were vaccinated; 622 (56%) received HD-IIV, and 485 (44%) received SD-IIV. Overall, 277 (19%) tested positive for influenza, including 98 (16%) who received HD-IIV, 87 (18%) who received SD-IIV, and 92 (24%) who were unvaccinated. After adjusting for confounding variables, effectiveness of SD-IIV was 6% (95% confidence interval [CI] −42%, 38%) and that of HD-IIV was 32% (95% CI −3%, 54%), for a relative effectiveness of HD-IIV versus SD-IIV of 27% (95% CI −1%, 48%). Conclusions During 2 US influenza seasons, vaccine effectiveness was low to moderate for prevention of influenza hospitalization among adults aged ≥65 years. High-dose vaccine offered greater effectiveness. None of these findings were statistically significant.


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