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Seqirus Announces Health Canada Approval of Expanded Age Indication of Its Cell-Based Quadrivalent Influenza Vaccine for People Two Years of Age and Older


Seqirus, a global leader in influenza prevention, announced that Health Canada has approved FLUCELVAX® QUADRIVALENT (Influenza Vaccine), its cell-based quadrivalent influenza vaccine (QIVc), for an expanded age indication for people two years of age and older. Health Canada previously approved FLUCELVAX QUADRIVALENT for use in persons nine years of age and older.[1] FLUCELVAX QUADRIVALENT will be available as a 0.5ml intramuscular (IM) vaccine per dose for the 2021/22 Canadian influenza season.

The expanded age indication is based on absolute efficacy data indicating that FLUCELVAX® QUADRIVALENT was effective and produced a sufficient immune response against influenza in children and adolescents between ≥2 to <18 years of age over three influenza seasons in the Southern (2017) and Northern (2017/18 and 2018/19) Hemispheres, compared to a non-influenza comparator.[2] This represents the first absolute efficacy study of a cell-based influenza vaccine in this population.

“Young children are at a high risk of complications from influenza, so annual vaccination is critical,” said Dr. Rupesh Chawla, Pediatric Infectious Disease Specialist. “The absolute efficacy data for FLUCELVAX® QUADRIVALENT that served as the basis for this approval indicate that the cell-based vaccine offers an important new option for children as young as two years of age.”

The Canadian Pediatric Society (CPS) encourages annual influenza vaccinations for all children and youth six months of age or older.[3] CPS agrees with the National Advisory Committee on Immunization’s (NACI) recommendation of using a quadrivalent vaccine containing two strains of influenza A and both lineages of influenza B for children and adolescents, as influenza B causes more mortality and morbidity in children than in adults.3

FLUCELVAX® QUADRIVALENT utilizes a cell-based influenza vaccine manufacturing process, an alternative to traditional egg-based manufacturing. Several factors can impact seasonal influenza vaccine effectiveness, including a mismatch between circulating strains and the influenza strains contained within the seasonal influenza vaccine. Egg-based manufacturing requires a growth-inducing strain to ensure the influenza virus can grow successfully in eggs, which can cause the strain to mutate and result in an influenza virus that can be different from the intended strain.[4],[5] This may lead to a mismatch between the circulating strains and the inactivated influenza strains contained within the seasonal influenza vaccine.5 Cell-based influenza vaccines like FLUCELVAX® QUADRIVALENT are designed to help avoid egg-adapted changes.5 They may result in vaccine virus strains that are more closely matched to those selected by the World Health Organization.5,[6] Cell-based influenza vaccine technology may offer additional advantages over the standard influenza manufacturing process, including being more scalable and offering faster production in the event of an influenza pandemic.5

“While influenza vaccination has always offered a way to minimize the burden of disease on the healthcare system, it is more important than ever this season to minimize the burden on the healthcare system and preserve capacity for COVID-19 patients,” said Gillian Stafford, Canada Commercial Director, Seqirus. “Especially now, we remain focused on our public health imperative to help protect as many people as possible against influenza, especially children.”

Seqirus plans to continue exploring other clinical research associated with FLUCELVAX QUADRIVALENT.

About Seasonal Influenza

Influenza is a common, contagious seasonal respiratory disease and can cause mild to severe illness, which can result in hospitalization or death.{7] Adults may spread influenza to others from 1 day before symptoms begin to approximately 5 days after symptoms start.7 Children and people with weakened immune systems may be infectious longer.7

Influenza is related to an average of 12,200 hospitalizations and approximately 3,500 deaths each year in Canada.7 Canada’s National Advisory Committee on Immunization (NACI) recommends annual influenza vaccination for all individuals six months of age and older.7 Further, NACI recommends the inclusion of all children between 6 and 59 months of age among the particularly recommended recipients of influenza vaccine.7

NACI recommends that healthcare providers in Canada offer the seasonal influenza vaccine as soon as feasible after it becomes available in the fall, since seasonal influenza activity may start as early as October in the Northern Hemisphere.7

About Seqirus

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

About CSL

CSL (ASX: CSL) is a leading global biotechnology company with a dynamic portfolio of life-saving medicines, including those that treat hemophilia and immune deficiencies, as well as vaccines to prevent influenza. Since our start in 1916, we have been driven by our promise to save lives using the latest technologies. Today, CSL – including our two businesses, CSL Behring and Seqirus – provides life-saving products to more than 100 countries and employs more than 27,000 people. Our unique combination of commercial strength, R&D focus and operational excellence enable us to identify, develop and deliver innovations so our patients can live life to the fullest. For more information about CSL Limited, visit

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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.

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Polina Miklush
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[2]  Fortanier, A.C., Põder, A., Bravo, L.C., et al. (2020). Efficacy of Cell-Derived Quadrivalent Influenza Vaccine Against Clinical Influenza in Children 2 to <18 Years of Age.

[3]  Canadian Pediatric Society (2020). Vaccine recommendations for children and youth for the 2020/2021 influenza season. Retrieved from Accessed March 2021.

[4]  Government of Canada. (2020). National Advisory Committee on Immunization Supplemental Statement – Mammalian Cell Culture-Based Influenza Vaccines. Retrieved from Accessed March 2021.

[5]  CDC (2020). Cell-Based Flu Vaccines. Retrieved from: Accessed March 2021.

[6]   Rajaram, S., Boikos, C., Gelone, et al. (2020). Influenza Vaccines: The Potential Benefits of Cell-Culture Isolation and Manufacturing.

[7]  Government of Canada. (2020). Canadian Immunization Guide Chapter on Influenza and Statement on Seasonal Influenza Vaccine for 2020–2021 Retrieved from: Accessed March 2021.