CSL Seqirus Presents Data at IDWeek 2024 Highlighting the Urgent Need to Increase Influenza Vaccination Rates and the Benefits of Cell-Based Influenza Vaccines

These studies were presented at the IDWeek 2024 conference in Los Angeles, California, in October 2024.

For several flu seasons, influenza vaccination rates in the U.S. have been in decline.^i,ii A dynamic model assessed eleven possible influenza vaccination rates, ranging from 20% to 70%, using data from two U.S. flu seasons (2011-2012 for low incidence and 2017-2018 for high incidence). An average vaccine effectiveness rate (VE) of 42% was used in the analysis, based on seasonal reports from the U.S. Centers for Disease Control and Prevention (CDC).¹ Findings indicated that lower vaccination rates, such as the 2023-24 season rate of ≈35%, would put considerable pressure on the U.S. hospital system.^1,iii In contrast, increasing the overall vaccination rate to at least 45% is needed to avoid the saturation of hospital resources, especially intensive care unit (ICU) hospital beds.¹

Other studies presented by CSL Seqirus at IDWeek include:

• Results from a retrospective test-negative design study of the 2022/23 season in the U.S. showed that cell-based quadrivalent (QIVc) vaccines prevented more outpatient test-confirmed influenza for those aged six months to 64 years compared with the egg-based quadrivalent (QIVe) vaccines.²
• Results from a systematic literature review of reported effectiveness during the 2017 to 2020 influenza seasons revealed a higher relative effectiveness of QIVc over QIVe/egg-based trivalent (TIVe) vaccines for those aged 4 to 64 years across the three influenza seasons for both test-confirmed influenza and clinically diagnosed influenza.³
• Results from a model study of the 2022/23 season in the U.S. estimated that a cell-based inactivated quadrivalent influenza vaccine (ccIIV4) would have averted a significant burden of influenza-related illnesses for those aged 0 to 64 years compared to an egg-based inactivated quadrivalent influenza vaccine (IIV4).⁴
• Results from a dynamic model study of the 2018 to 2020 influenza seasons in the U.S., calibrated with data from the CDC and published U.S. observational studies, indicated that QIVc was cost saving compared to the recombinant influenza vaccine (QIVr) for those aged 18 to 64 years and achieved comparable health outcomes results at a significant reduction in cost.^iv

These studies add to the growing body of evidence showcasing the benefits of cell-based influenza vaccines compared to standard-dose egg-based influenza vaccines, including the prevention of influenza infections and related complications.^2,3,4,8 Moreover, the use of cell-based vaccines was estimated to be associated with substantial economic savings due to lower healthcare utilization and reduced direct medical costs.⁸

“The results from these studies, collected and analyzed over several recent influenza seasons, have shown that cell-based influenza vaccines are effective in preventing both test-confirmed and clinically diagnosed influenza,” stated Mendel Haag, Senior Director, Center of Outcomes Research & Epidemiology at CSL Seqirus. “Data presented at this year’s IDWeek further reinforce the importance of protecting people against influenza, particularly in our more vulnerable populations, including children as young as six months. This real-world evidence underscores the critical role of cell-based influenza vaccines in improving public health outcomes and easing the burden on healthcare systems during flu seasons.”

For more information about the data being presented at IDWeek 2024, refer to the related document.

Study Limitations

The above studies featuring RWE were subject to the typical limitations associated with retrospective cohort analyses. Unmeasured and residual confounding remain a potential source of bias as in all observational research. Additionally, vaccination in these observational studies was not randomly assigned.

As with all simulations, analyses based on models have several limitations based on a model’s parameters and available data, as well as annually varying vaccine effectiveness. Modeling may underestimate the true number of cases averted for several reasons and studies may not account for the indirect benefits of vaccination or capture potential variability between sub-groups.

About Seasonal Influenza

Influenza is a frequently occurring, contagious seasonal respiratory disease that may cause severe illness and life-threatening complications in some people.⁹  Influenza can lead to clinical symptoms varying from mild to moderate respiratory illness to severe complications, hospitalization and in some cases, death.⁹ Because transmission of influenza viruses to others may occur before symptoms develop and up to 5 to 7 days after becoming sick, the disease can be easily transmitted to others. ⁹ Influenza causes an average of 12,200 hospitalizations and approximately 3,500 deaths each year in Canada.¹⁰ The National Advisory Committee on Immunization (NACI) recommends  that influenza vaccine should be offered annually to anyone 6 months of age and older who does not have a contraindication to the vaccine.¹⁰ Since it takes about two weeks after vaccination for antibodies to develop in the body and help protect against influenza virus infection, it is recommended that people get vaccinated before influenza begins spreading in their community.¹¹ The NACI recommends that people get vaccinated as soon as feasible after the vaccines become available in the fall.¹⁰

About CSL Seqirus

CSL Seqirus is part of CSL (ASX: CSL). As one of the largest influenza vaccine providers in the world, CSL Seqirus is a major contributor to the prevention of influenza globally and a transcontinental partner in pandemic preparedness. With state-of-the-art production facilities in the U.S., the U.K. and Australia, CSL Seqirus utilizes egg, cell and adjuvant technologies to offer a broad portfolio of differentiated influenza vaccines in more than 20 countries around the world.

For more information about CSL Seqirus, visit www.CSL.com.

About CSL

CSL (ASX:CSL; USOTC:CSLLY) is a global biotechnology company with a dynamic portfolio of lifesaving medicines, including those that treat hemophilia and immune deficiencies, vaccines to prevent influenza, and therapies in iron deficiency and nephrology. Since our start in 1916, we have been driven by our promise to save lives using the latest technologies. Today, CSL – including our three businesses: CSL Behring, CSL Seqirus and CSL Vifor – provides lifesaving products to patients in more than 100 countries and employs 32,000 people. Our unique combination of commercial strength, R&D focus and operational excellence enables us to identify, develop and deliver innovations so our patients can live life to the fullest. For inspiring stories about the promise of biotechnology, visit CSL.com/we-are-csl/vita-original-stories and follow us on x.com/CSL.

For more information about CSL Limited, visit www.CSL.com.

Intended Audience 

This press release is issued from CSL Seqirus in Montreal, Quebec, Canada and is intended to provide information about our global business. Please be aware that information relating to the approval status and labels of approved CSL Seqirus products may vary from country to country. Please consult your local regulatory authority on the approval status of CSL Seqirus products.

Forward-Looking Statements 

This press release may contain 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. 

FLUCELVAX^® QUAD

Influenza Vaccine (surface antigen, inactivated, prepared in cell cultures)

Indication and clinical use:

FLUCELVAX^® QUAD is a quadrivalent inactivated vaccine indicated for active immunization of adults and children aged 6 months or older for the prevention of influenza disease caused by influenza virus subtypes A and types B contained in the vaccine.

Relevant warnings and precautions:

Do not use FLUCELVAX^® QUAD if:

• child is under 6 months of age. FLUCELVAX^® QUAD vaccine is only approved for use in children aged 6 months and older.
• the person has an allergy to FLUCELVAX^® QUAD or any ingredient listed.

To help avoid side effects and ensure proper use, speak to a healthcare professional before taking FLUCELVAX^® QUAD. Talk about any health conditions or problems, including if the person may:

• have or have had a reaction to vaccination with any of the following:

  • severe allergic reaction

  • difficulty breathing

  • swelling of the throat

  • fainting or collapse

  • fits or convulsions

  • high temperature (greater than 38.5°C)

  • severe skin reaction at the injection site, including severe bruising

• have an infection or temperature higher than 38.5°C.
• have low immunity due to treatment with certain medicines
• have or have had Guillain-Barré Syndrome (GBS), an illness which affects the nervous system and causes paralysis.
• have allergies to other medicines or substances
• are pregnant or breastfeeding.
• have experienced fainting, or feeling faint, with a previous injection.

For more information about FLUCELVAX^® QUAD:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes this Patient Medication Information by visiting the Health Canada website:

(https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drugproduct-database.html; the manufacturer’s website www.seqirus.ca, or by calling 1-855-358-8966.

FLUAD^®

Influenza vaccine (surface antigen, inactivated, adjuvanted with MF59^®)

Indication and clinical use:

FLUAD^® is an inactivated influenza vaccine indicated for active immunization against influenza disease caused by influenza virus subtypes A and B contained in the vaccine in adults 65 years of age and older.

Relevant warnings and precautions:

Do not use FLUAD^® if:

• there is a history of hypersensitivity to egg proteins or other components of the vaccine, any of the excipients or in people who have had a life-threatening reaction to previous influenza vaccination.

   

  To help avoid side effects and ensure proper use, speak to a healthcare professional before receiving FLUAD^®. Talk about any health conditions or problems including:

• are/is allergic to eggs or egg-products
• are/is allergic to any of the following: kanamycin and neomycin sulphate, hydrocortisone, formaldehyde, cetyltrimethylammonium bromide, or polysorbate 80
• have/has a fever, or think you may be getting a fever
• had a serious reaction to any flu vaccine in the past
• have/has any known allergies
• have/has experienced any health problems
• are pregnant: ask your doctor for advice
• are/is currently on any medication (i.e. immunosuppressant, theophylline, anticoagulants such as warfarin)

Other warnings:

FLUAD^® should not be administered to anyone with known allergies to eggs or egg products, or any other constituent of the vaccine or to anyone who has had a life-threatening reaction to previous influenza vaccination.

If Guillain-Barré Syndrome (GBS) has occurred within six weeks of previous influenza vaccination, the decision to give FLUAD^® should be based on careful consideration of the potential benefits and risks.

Immunocompromised patients may have a diminished immune response to FLUAD^®.

FLUAD^® may be given at the same time as other vaccines. There are no data to assess the concomitant administration of FLUAD^® with other vaccines.

As with any vaccine, immunization with FLUAD^® may not protect 100% of individuals against influenza disease.

Immunosuppressive therapies may reduce immune response to FLUAD^®

For more information:

Find the full product monograph that is prepared for healthcare professionals and includes Patient Medication Information by visiting the Health Canada website:

(https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drugproduct-database.html; the manufacturer’s website http://www.seqirus.ca, or by calling 1-855-358-8966.

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CAN-SEQ-24-0039

MEDIA CONTACT

Tiffany Cody

+1 (908) 370-1863

Tiffany.Cody@Seqirus.com

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