scholarly journals Relative Effectiveness of the Cell-Cultured Quadrivalent Influenza Vaccine Compared to Standard, Egg-derived Quadrivalent Influenza Vaccines in Preventing Influenza-like Illness in 2017–2018

2020 ◽  
Vol 71 (10) ◽  
pp. e665-e671 ◽  
Author(s):  
Constantina Boikos ◽  
Gregg C Sylvester ◽  
John S Sampalis ◽  
James A Mansi

Abstract Background Influenza antigens may undergo adaptive mutations during egg-based vaccine production. In the 2017–2018 influenza season, quadrivalent, inactivated cell-derived influenza vaccine (ccIIV4) vaccine was produced using A(H3N2) seed virus propagated exclusively in cell culture, thus lacking egg adaptive changes. This United States study estimated relative vaccine effectiveness (rVE) of ccIIV4 vs egg-derived quadrivalent vaccines (egg-derived IIV4) for that season. Methods Vaccination, outcome, and covariate data were ascertained retrospectively from a electronic medical record (EMR) dataset and analyzed. The study cohort included patients ≥ 4 years of age. rVE was estimated against influenza-like illness (ILI) using diagnostic International Classification of Diseases, Ninth or Tenth Revision codes. The adjusted odds ratios used to derive rVE estimates were estimated from multivariable logistic regression models adjusted for age, sex, race/ethnicity, geographic region, and health status. Results Overall, 92 187 individuals had a primary care EMR record of ccIIV4 and 1 261 675 had a record of egg-derived IIV4. In the ccIIV4 group, 1705 narrowly defined ILI events occurred, and 25 645 occurred in the standard egg-derived IIV4 group. Crude rVE was 9.2% (95% confidence interval [CI], 4.6%–13.6%). When adjusted for age, sex, health status, comorbidities, and geographic region, the estimated rVE changed to 36.2% (95% CI, 26.1%–44.9%). Conclusions ccIIV4, derived from A(H3N2) seed virus propagated exclusively in cell culture, was more effective than egg-derived IIV4 in preventing ILI during the 2017–2018 influenza season. This result suggests that cell-derived influenza vaccines may have greater effectiveness than standard egg-derived vaccines.

Author(s):  
Constantina Boikos ◽  
Mahrukh Imran ◽  
Van Hung Nguyen ◽  
Thierry Ducruet ◽  
Gregg C Sylvester ◽  
...  

Abstract Background Higher rates of influenza-related morbidity and mortality occur in individuals with underlying medical conditions. To improve vaccine effectiveness, cell-based technology for influenza vaccine manufacturing has been developed. Cell–derived inactivated quadrivalent influenza vaccines (cIIV4) may improve protection in seasons where egg-propagated influenza viruses undergo mutations that affect antigenicity. This study aimed to estimate the relative vaccine effectiveness (rVE) of cIIV4 versus egg-derived inactivated quadrivalent influenza vaccines (eIIV4) in preventing influenza-related medical encounters in individuals with underlying medical conditions putting them at high risk of influenza complications during the 2018-2019 U.S. influenza season. Methods An integrated dataset, linking primary care electronic medical records with claims data, was used to conduct a retrospective cohort study among individuals aged ≥4 years, with ≥1 health condition, vaccinated with cIIV4 or eIIV4 during the 2018-2019 season. Adjusted odds ratios (ORs) were derived using a doubly robust inverse probability of treatment-weighting (IPTW) model, adjusting for age, sex, race, ethnicity, geographic region, vaccination week, and health status. rVE was estimated by (1- OR)*100 and presented with 95% confidence intervals (CI). Results The study cohort included 471,301 cIIV4 and 1,641,915 eIIV4 recipients. Compared with eIIV4, cIIV4 prevented significantly more influenza-related medical encounters among individuals with ≥1 health condition (rVE 13.4% [95% CI 11.4-15.4]); chronic pulmonary disease (18.7% [16.0-21.3]); and rheumatic disease (11.8% [3.6-19.3]). Conclusions Our findings support the use of cIIV4 in individuals ≥4 years of age at high risk of influenza complications and provide further evidence supporting improved effectiveness of cIIV4 compared to eIIV4.


Author(s):  
Constantina Boikos ◽  
Lauren Fischer ◽  
Dan O’Brien ◽  
Joe Vasey ◽  
Gregg C Sylvester ◽  
...  

Abstract Background The cell-propagated inactivated quadrivalent influenza vaccine (ccIIV4) may offer improved protection in seasons where egg-derived influenza viruses undergo mutations that affect antigenicity. This study estimated the relative vaccine effectiveness (rVE) of ccIIV4 versus egg-derived inactivated quadrivalent influenza vaccine (eIIV4) in preventing influenza-related medical encounters in the 2018-2019 U.S. season. Methods A dataset linking primary care electronic medical records with medical claims data was used to conduct a retrospective cohort study among individuals ≥4 years vaccinated with ccIIV4 or eIIV4 during the 2018-2019 season. Adjusted odds ratios (ORs) were derived from a doubly robust inverse probability of treatment-weighted approach adjusting for age, sex, race, ethnicity, geographic region, vaccination week, and health status. Relative vaccine effectiveness (rVE) was estimated by (1-OR)*100 and presented with 95% confidence intervals (CI). Results Following the application of inclusion/exclusion criteria, the study cohort included 2,125,430 ccIIV4 and 8,000,903 eIIV4 recipients. Adjusted analyses demonstrated a greater reduction in influenza-related medical encounters with ccIIV4 versus eIIV4, with the following rVE: overall, 7.6% (95% CI 6.5-8.6); age 4-17 years, 3.9% (0.9-7.0); 18-64 years, 6.5% (5.2-7.9); 18-49 years, 7.5% (5.7-9.3); 50-64 years, 5.6% (3.6-7.6); and ≥65 years, -2.2% (-5.4 to 0.9). Conclusions Adjusted analyses demonstrated statistically significantly greater reduction in influenza-related medical encounters in individuals vaccinated with ccIIV4 vs eIIV4 in the 2018-2019 U.S. influenza season. These results support ccIIV4 as a potentially more effective public health measure against influenza than an egg-based equivalent.


Author(s):  
Victoria Divino ◽  
Vamshi Ruthwik Anupindi ◽  
Mitch DeKoven ◽  
Joaquin Mould-Quevedo ◽  
Stephen I Pelton ◽  
...  

Abstract Background Cell-derived influenza vaccines are not subject to egg adaptive mutations that have potential to decrease vaccine effectiveness. This retrospective analysis estimated the relative vaccine effectiveness (rVE) of cell-derived quadrivalent influenza vaccine (IIV4c) compared to standard egg-derived quadrivalent influenza vaccines (IIV4e) among recipients aged 4-64 years in the US during the 2019-20 influenza season. Methods The IQVIA PharMetrics® Plus administrative claims database was utilized. Study outcomes were assessed post-vaccination through the end of the study period (March 7, 2020). Inverse probability of treatment weighting (IPTW) was implemented to adjust for covariate imbalance. Adjusted rVE against influenza-related hospitalizations/emergency room (ER) visits and other clinical outcomes was estimated through IPTW-weighted Poisson regression models for the IIV4c and IIV4e cohorts and for the subgroup with ≥1 high-risk condition. Sensitivity analyses modifying the outcome assessment period as well as a doubly-robust analysis were also conducted. IPTW-weighted generalized linear models were used to estimate predicted annualized all-cause costs. Results The final sample comprised 1,138,969 IIV4c and 3,926,357 IIV4e recipients following IPTW adjustment. IIV4c was more effective in preventing influenza-related hospitalizations/ER visits as well as respiratory-related hospitalizations/ER visits compared to IIV4e. IIV4c was also more effective for the high-risk subgroup and across the sensitivity analyses. IIV4c was also associated with significantly lower annualized all-cause total costs compared to IIV4e (-$467), driven by lower costs for outpatient medical services and inpatient hospitalizations. Conclusions IIV4c was significantly more effective in preventing influenza-related hospitalizations/ER visits compared to IIV4e and was associated with significantly lower all-cause costs.


Author(s):  
Constantina Boikos ◽  
Lauren Fischer ◽  
Dan O’Brien ◽  
Joe Vasey ◽  
Gregg C Sylvester ◽  
...  

Abstract Background The effectiveness of standard, egg-derived quadrivalent influenza vaccines (IIV4) may be reduced in adults ≥65 years of age, largely because of immunosenescence. An MF59-adjuvanted trivalent influenza vaccine (aIIV3) and a high-dose trivalent influenza vaccine (HD-IIV3) offer older adults enhanced protection versus standard vaccines. This study compared the relative effectiveness of aIIV3 with IIV4 and HD-IIV3 in preventing influenza-related medical encounters over 2 US influenza seasons. Methods This retrospective cohort study included US patients ≥65 years vaccinated with aIIV3, IIV4, or HD-IIV3. The outcome of interest was the occurrence of influenza-related medical encounters. Data were derived from a large dataset comprising primary and specialty care electronic medical records linked with pharmacy and medical claims. Adjusted odds ratios (OR) were derived from an inverse probability of treatment-weighted sample adjusted for age, sex, race, ethnicity, geographic region, vaccination week, and health status. Relative vaccine effectiveness (rVE) was determined using the formula (% VE = 1 – ORadjusted) × 100. Results In 2017–2018, cohorts included: aIIV3, n = 524 223; IIV4, n = 917 609; and HD-IIV3, n = 3 377 860. After adjustment, 2017–2018 rVE of aIIV3 versus IIV4 was 18.2 (95% confidence interval [CI], 15.8–20.5); aIIV3 vs. HD-IIV3 was 7.7 (95% CI, 2.3–12.8). In 2018–2019, cohorts included: aIIV3, n = 1 031 145; IIV4, n = 915 380; HD-IIV3, n = 3 809 601, with adjusted rVEs of aIIV3 versus IIV4 of 27.8 (95% CI, 25.7–29.9) and vs. HD-IIV3 of 6.9 (95% CI, 3.1–10.6). Conclusion In the 2017–2018 and 2018–2019 influenza seasons in the United States, aIIV3 demonstrated greater reduction in influenza-related medical encounters than IIV4 and HD-IIV3 in adults ≥65 years.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S136-S136
Author(s):  
myron J levin ◽  
Victoria Divino ◽  
Stephen I Pelton ◽  
Maarten Postma ◽  
Drishti Shah ◽  
...  

Abstract Background According to the Centers for Disease Control and Prevention (CDC), during the 2019-20 U.S. influenza season, influenza resulted in almost 180,000 hospitalizations and over 13,000 deaths in adults ≥ 65 years. The current study evaluated the relative vaccine effectiveness (rVE) of adjuvanted trivalent influenza vaccine (aTIV) compared to high-dose trivalent influenza vaccine (TIV-HD), against influenza-related hospitalizations/emergency room (ER) visits, all-cause hospitalizations and hospitalizations/ER visits for cardio-respiratory disease (CRD) among adults ≥65 years for the 2019-20 influenza season. Methods A retrospective cohort analysis of older adults (≥ 65 years) was conducted using IQVIA’s professional fee, prescription claims and hospital charge master data in the U.S. Baseline characteristics included age, gender, payer type, geographic region, Charlson Comorbidity Index (CCI), comorbidities, indicators of frail health status, and pre-index hospitalization rates. To avoid any influenza outcome misclassification with COVID-19 infection, the study period ended March 7, 2020. Adjusted analyses were conducted through inverse probability of treatment weighting (IPTW) to control for selection bias. Poisson regression was used to estimate the adjusted pairwise rVE against influenza-related hospitalizations/ER visits, all-cause hospitalizations and any hospitalization/ER visit for CRD. An unrelated negative control outcome, urinary tract infection (UTI) hospitalization was included. Results During the 2019-20 influenza season, following IPTW, 798,987 recipients of aTIV and 1,655,979 recipients of TIV-HD were identified. After IPTW adjustment and Poisson regression, aTIV was statistically comparable to TIV-HD for prevention of influenza-related hospitalizations/ER visits (3.1%; 95% CI: -2.8%-8.6%) and all-cause hospitalizations (-0.7%; 95% CI: -1.6%-0.3%). Similar comparable outcomes were found for reduction of any hospitalization/ER visit for CRD (0.9%; 95% CI: 0.0%-1.7%). No treatment effect was identified for the negative control outcome. Conclusion aTIV and TIV-HD demonstrated comparable reductions in influenza-related hospitalizations/ER visits, all-cause hospitalizations and hospitalizations/ER visits for CRD. Disclosures myron J. levin, MD, GSK group of companies (Employee, Research Grant or Support) Victoria Divino, PhD, Seqirus (Consultant) Stephen I. Pelton, MD, Seqirus (Consultant) Maarten Postma, Dr., Seqirus (Consultant) Drishti Shah, PhD, Seqirus (Consultant) Joaquin F. Mould-Quevedo, PhD, Seqirus (Employee) Mitchell DeKoven, PhD, Seqirus (Consultant)


Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 657
Author(s):  
Jai S. Bolton ◽  
Hannah Klim ◽  
Judith Wellens ◽  
Matthew Edmans ◽  
Uri Obolski ◽  
...  

The antigenic drift theory states that influenza evolves via the gradual accumulation of mutations, decreasing a host’s immune protection against previous strains. Influenza vaccines are designed accordingly, under the premise of antigenic drift. However, a paradox exists at the centre of influenza research. If influenza evolved primarily through mutation in multiple epitopes, multiple influenza strains should co-circulate. Such a multitude of strains would render influenza vaccines quickly inefficacious. Instead, a single or limited number of strains dominate circulation each influenza season. Unless additional constraints are placed on the evolution of influenza, antigenic drift does not adequately explain these observations. Here, we explore the constraints placed on antigenic drift and a competing theory of influenza evolution – antigenic thrift. In contrast to antigenic drift, antigenic thrift states that immune selection targets epitopes of limited variability, which constrain the variability of the virus. We explain the implications of antigenic drift and antigenic thrift and explore their current and potential uses in the context of influenza vaccine design.


Author(s):  
Joan Puig-Barberà ◽  
Sonia Tamames-Gómez ◽  
Pedro Plans-Rubio ◽  
José María Eirós-Bouza

Avian mutations in vaccine strains obtained from embryonated eggs could impair vaccine effec-tiveness. We performed a systematic review and meta-analysis of the adjusted relative vaccine effectiveness (arVE) of seed cell-cultured influenza vaccines (ccIV) compared to egg-based influ-enza vaccines (eIV) in preventing laboratory-confirmed influenza related outcomes (IRO) or IRO by clinical codes, in subjects 18 and over. We completed the literature search in January 2021; ap-plied exclusion criteria, evaluated risk of bias of the evidence, and performed heterogeneity, pub-lication bias, qualitative, quantitative and sensitivity analyses. All estimates were computed us-ing a random approach. International Prospective Register of Systematic Reviews, CRD42021228290. We identified 12 publications that reported 26 adjusted arVE results. Five publications reported 13 laboratory confirmed arVE and seven reported 13 code-ascertained arVE. Nine publications with 22 results were at low risk of bias. Heterogeneity was explained by season and risk of bias. We found a significant 11% (8 to 14%) adjusted arVE favoring ccIV in preventing any IRO in the 2017-2018 influenza season. The arVE was 3% (-01 to 7%) in the 2018-2019 influenza season. We found moderate evidence of a significant advantage of the ccIV in preventing IRO, compared to eIV, in a well-matched A(H3N2) predominant season.


2020 ◽  
Vol 7 (1) ◽  
pp. 495-512
Author(s):  
Sigrid Gouma ◽  
Elizabeth M. Anderson ◽  
Scott E. Hensley

Seasonal influenza vaccines prevent influenza-related illnesses, hospitalizations, and deaths. However, these vaccines are not as effective as other viral vaccines, and there is clearly room for improvement. Here, we review the history of seasonal influenza vaccines, describe challenges associated with producing influenza vaccine antigens, and discuss the inherent difficulties of updating influenza vaccine strains each influenza season. We argue that seasonal influenza vaccines can be dramatically improved by modernizing antigen production processes and developing models that are better at predicting viral evolution. Resources should be specifically dedicated to improving seasonal influenza vaccines while developing entirely new vaccine platforms.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S970-S970
Author(s):  
Vivek Shinde ◽  
Rongman Cai ◽  
Joyce S Plested ◽  
Bin Zhou ◽  
Haixia Zhou ◽  
...  

Abstract Background We developed a recombinant saponin-adjuvanted (Matrix-M1) quadrivalent hemagglutinin nanoparticle influenza vaccine (qNIV; NanoFlu) for older adults to address two impediments to efficacy of current, predominantly egg-derived, seasonal influenza vaccines: (1) limited protection against antigenic drift variants, particularly H3N2 viruses; and (2) antigenic mismatch between vaccine and circulating strains due to egg-adaptive mutations arising during manufacturing. In a prior Phase 1 trial, we showed that qNIV induced robust, broadly cross-reactive antibody responses against multiple antigenically drifted H3N2 viruses, which were 47–64% better than the egg-derived comparator trivalent high-dose inactivated influenza vaccine (IIV3-HD; Fluzone-High Dose). We undertook a Phase 2 trial to optimize the formulation of qNIV, and to compare qNIV immune responses to those of IIV3-HD and quadrivalent recombinant influenza vaccine (RIV4; FluBlok). Methods In this phase 2 dose and formulation finding RCT, we randomized 1,375 subjects aged ≥65 years to be immunized with 1 of 7 test vaccines: 5 different formulations of qNIV, IIV3-HD, or RIV4; and assessed wild-type hemagglutinin-inhibition (wt-HAI) and microneutralization (wt-MN) antibody responses (Day 0/28/56). Results Matrix-M1-adjuvanted qNIV induced 15–29% higher wt-HAI titers across 5 vaccine homologous or drifted H3N2 strains at Day 28 relative to unadjuvanted qNIV (statistically significantly superior for 5 of 6 strains tested). At Day 28, several qNIV formulations induced significantly superior wt-HAI titers vs. IIV3-HD (39–45%, 17–22%, and 44–48% greater titers for homologous A/Singapore/INFIMH-16–0019/2016—H3N2, historic-drifted A/Switzerland/9715293/2013—H3N2, and forward-drifted A/Wisconsin/19/2017—H3N2, respectively); and comparable HAI titers vs. RIV4. Wt-MN and wt-HAI data showed concordant patterns across treatment groups. Conclusion qNIV induced superior wt-HAI antibody responses vs. IIV3-HD against homologous or drifted H3N2 viruses and similar responses to RIV4. qNIV may address several critical challenges confronting current egg-derived influenza vaccines, especially in the older adult population. Disclosures All authors: No reported disclosures.


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