Seqirus, a global leader in influenza prevention, today released a new real-world evidence analysis indicating that its cell-based quadrivalent influenza vaccine (QIVc) was 36.2 percent more effective than standard egg-based quadrivalent vaccine (QIVe) in preventing influenza-like illness (ILI) captured within primary care visits in people aged 4 years and above during the 2017/18 influenza season in the United States, a season characterized by egg-adapted changes.1
The 2017/18 season in the U.S. was considered to be one of the worst in recent years due to the predominance of the H3N2 influenza virus.2 Research has shown that some H3N2 viruses undergo changes when they are grown in eggs, and that these changes may reduce the effectiveness of standard egg-based influenza vaccines in H3N2-dominated seasons. When produced completely outside of the egg-based process, cell-based influenza vaccines avoid egg-adapted changes, which means they may offer a closer match and potentially improved protection compared to standard egg-based options in some seasons.3,4,5,6,7,8
“Real-world evidence is critical in evaluating influenza vaccine effectiveness for continued advances in influenza prevention, and these new data are some of the most robust we have seen to date,” said Russell Basser MD, SVP of Research and Development, Seqirus. “This study, along with other burgeoning evidence, indicates that cell-based vaccines may result in better influenza-related outcomes compared to standard vaccine options in some seasons, particularly those characterized by egg-adapted changes.”
The data from this Seqirus commissioned study, generated from one of the largest electronic medical record (EMR) providers for primary care practices in the U.S., were presented at the recent National Foundation for Infectious Disease (NFID) 2018 Clinical Vaccinology Course. Seqirus studied data from 1,353,862 patient records to determine effectiveness of QIVc to prevent ILI compared to QIVe.1
Real-world data from one of the largest electronic medical record (EMR) providers for primary care practices in the U.S. were obtained between August 1, 2017 and March 31, 2018. Seqirus evaluated these data as a retrospective cohort study which allowed for the estimation of the relative vaccine effectiveness (rVE) of cell-based quadrivalent, inactive influenza vaccine (QIVc) versus egg-based, quadrivalent, inactive influenza vaccine (QIVe).
Researchers analyzed EMRs from 92,192 subjects who received a QIVc and 1,255,983 subjects who received a QIVe to determine which vaccine was more effective in preventing influenza-like illness (ILI). While the effectiveness outcome evaluated in this real-world analysis was not polymerase chain reaction (PCR) confirmed, ILI is an effectiveness outcome used by the Centers for Disease Control (CDC) and World Health Organization (WHO) and reflects exposure and outcome experiences during routine clinical practice. The study population included patients ages 4 years and above who received either QIVe or QIVc in primary care, in the U.S., during this period. Exposures (QIVc or QIVe) were derived from recorded immunizations in individual patients EMRs.
The rVE estimated from the study’s primary analysis indicated that QIVc was more effective than standard egg-based QIVs in preventing ILI (rVE of 36.2%, 95% CI (26.1,44.9; P<0.001)). Potential study limitations were minimized using stringent quality control of the data set, cross-referencing the exposure classification step, evaluating two different outcomes code sets for ILI, adjusting for key variables and conducting multiple sensitivity analyses.10
This press release is issued from Seqirus USA Inc. in Summit New Jersey, USA and is intended to provide information about our global business. Please be aware that information relating to the approval status and labels of approved Seqirus products may vary from country to country.
This press release contains forward-looking statements, including statements regarding future results, performance or achievements. These statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements.
1 Boikos T. (2018). Effectiveness of the Cell Culture- and Egg-Derived, Seasonal Influenza Vaccine during the 2017-2018 Northern Hemisphere Influenza Season. Presented at NFID Clinical Vaccinology Course, November 2018.
2 Centers for Disease Control and Prevention (CDC). (2018). Estimated influenza illnesses, medical visits, hospitalizations, and deaths in the United States — 2017–2018 influenza season. Retrieved from: https://www.cdc.gov/flu/about/burden/estimates.htm Accessed November 2018.
3 Rajaram S., Van Boxmeer J., Leav B., et al. (2018). Retrospective evaluation of mismatch from egg-based isolation of influenza strains compared to cell-based isolation and the possible implications for vaccine effectiveness. Presented at IDWeek 2018, October 2018.
4 CDC. (2018). Advisory Committee on Immunization Practices (ACIP) Presentation Slides: June 2018 Meeting. Retrieved from https://www.cdc.gov/vaccines/acip/meetings/slides-2018-06.html Accessed November 2018.
5 Zost S.J., Parkhouse K., Gumina M.E., et al. (2017). Contemporary H3N2 influenza viruses have a glycosylation site that alters binding of antibodies elicited by egg-adapted vaccine strains. PNAS, 114(47)12578-12583. doi:10.1073/pnas.1712377114.
6 Wu N.C., Zost S.J., Thompson A.J., et al. (2017). A structural explanation for the low effectiveness of the seasonal influenza H3N2 vaccine. PLOS Pathogens, 13(10): e1006682. doi:10.1371/journal.ppat.1006682.
7 The Francis Crick Institute. (2018). Worldwide Influenza Centre: Annual and Interim Reports – February 2018 interim report. Retrieved from https://www.crick.ac.uk/research/worldwide-influenza-centre/annual-and-interim-reports/ Accessed November 2018.
8 CDC. (2018). Cell-Based Flu Vaccines. Retrieved from: https://www.cdc.gov/flu/protect/vaccine/cell-based.htm Accessed November 2018.
9 This project has been funded in whole or in part with Federal funds from the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under contract numbers HHSO100200600012C, HHSO100200700030C, HHSO100200900101C and HHSO100201200003I.
10 Armed Forces Health Surveillance Center (AFHSC): Influenza-Like Illness (ILI). (2015). Retrieved from https://www.health.mil/Reference-Center/Publications/2015/10/01/Influenza-Like-Illness Accessed November 2018.
11 CDC. (2018). Key facts about seasonal flu vaccine. Retrieved from: http://www.cdc.gov/flu/protect/keyfacts.htm Accessed November 2018.
12 CDC. (2018). How flu spreads. Retrieved from: https://www.cdc.gov/flu/about/disease/spread.htm Accessed November 2018.