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CSL Seqirus Commences Shipping Its Portfolio of Influenza Vaccines to Healthcare Providers in Preparation for the 2025/26 Flu Season

CSL Seqirus is the only manufacturer to offer a differentiated influenza vaccine portfolio for all eligible age groups in the U.S.
According to the U.S. Centers for Disease Control and Prevention (CDC), it is recommended that all eligible people aged six months and older receive an annual influenza vaccine, especially people at an increased risk of severe influenza-related complications, such as older adults, pregnant people, and children under five years old.[1,2]
CDC data indicate a significant decline in influenza vaccination rates since the 2020/21 season, with the 2024/25 season being called the worst influenza season in 15 years.[1,3,4,5}

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CSL Seqirus, a business of CSL (ASX:CSL), today announced that the company has commenced shipping its differentiated portfolio of influenza vaccines for the 2025/26 U.S. season. As a global leader in influenza prevention, CSL Seqirus is committed to timely and consistent delivery of its influenza vaccines to enable immunizers to help protect as many eligible individuals as possible against influenza and its complications.

“During this past flu season, doctors’ offices, emergency departments and hospitals across the country were filled with patients affected by the flu,” said Gregg Sylvester, Chief Health Officer, CSL Seqirus. “We experienced the impact flu can have on our communities, our healthcare systems, and in our own homes. To make sure this doesn’t happen again, vaccination is the first and most important action to help prevent flu and its potentially serious consequences.”


The 2024/25 influenza season was an indication of the profound impact that low vaccination rates can have on health outcomes, with this past season being called the worst influenza season in 15 years.4,5 In particular, the 256 total influenza-associated pediatric deaths and cumulative hospitalization rate during this past influenza season were the highest recorded since the 2010/11 season.5,6 Notably, among children who were eligible for influenza vaccination and with known vaccination status, 90% of the reported pediatric deaths occurred in children who were not fully vaccinated against influenza.6

"Given the high severity of last flu season, the timely delivery of flu vaccines is more important than ever, allowing healthcare providers to prepare for and begin vaccinations ahead of the season and continue throughout,” said Stefan Merlo, Vice President of Commercial Operations, North America, CSL Seqirus. “In light of this, we are fully committed to supporting our partners in their efforts to protect the health of their communities by offering a differentiated portfolio of flu vaccines with options designed to provide higher levels of protection compared to traditional vaccines, helping address factors that commonly impact vaccine effectiveness.”

Following the CDC’s Advisory Committee for Immunization Practices (ACIP) continued support of a universal recommendation for annual influenza vaccination for eligible people six months and older, CSL Seqirus is ready and committed to continued partnership with healthcare providers to increase immunization rates and protect public health. CSL Seqirus remains confident that our vaccine supply and shipment timing will meet all of our customers’ needs for the upcoming influenza season.

CSL Seqirus is the only manufacturer to offer a differentiated influenza vaccine option approved for use across recommended age groups. This year’s 2025/26 U.S. influenza season portfolio includes:

  • FLUCELVAX® (Influenza Vaccine), the first and only cell-based influenza vaccine for patients six months and older that is made with cell-based technology that offers an exact match to WHO-selected strains that can result in higher vaccine effectiveness.7
  • FLUAD® (Influenza Vaccine, Adjuvanted), the first and only adjuvanted seasonal influenza vaccine for adults 65 and older, which is preferentially recommended by the CDC’s Advisory Committee on Immunization Practices (ACIP) over standard-dose influenza vaccines.8,9
  • AFLURIA® (Influenza Vaccine), an egg-based, influenza vaccine approved for use in eligible people six months of age and older.10

For additional information on our influenza vaccines for the upcoming influenza season, visit the CSL Seqirus U.S. products page, and if you are a healthcare professional, visit flu360.com.

About Seasonal Influenza

Influenza is a common, contagious seasonal respiratory disease that may cause severe illness and life-threatening complications in some people.11 Influenza can lead to clinical symptoms varying from mild to moderate respiratory illness to severe complications, hospitalization and in some cases, death.11 Because transmission of influenza viruses to others may occur one day before symptoms develop and up to five to seven days after becoming sick, the disease can be easily transmitted to others.11 Preliminary estimates from the Centers for Disease Control and Prevention (CDC) report that during the 2024/25 influenza season, there were an estimated 610,000-1.3 million influenza-related hospitalizations in the U.S.12 The CDC recommends annual vaccination for people aged six months and older, who do not have any contraindications.1 Since it takes about two weeks after vaccination for antibodies to develop in the body that help protect against influenza virus infection, it is recommended that people get vaccinated before influenza begins spreading in their community.1 The CDC recommends that for most people who need only one dose of flu vaccine, vaccination should ideally happen in September or October.1

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 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 haemophilia 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 CSLBehring.com/Vita and follow us on Twitter.com/CSL.

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

Intended Audience

This press release is issued from CSL Seqirus 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 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.

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FLUAD® (Influenza Vaccine, Adjuvanted), FLUCELVAX® (Influenza Vaccine), and AFLURIA® (Influenza Vaccine)

IMPORTANT SAFETY INFORMATION

What are FLUAD® (Influenza Vaccine, Adjuvanted), FLUCELVAX® (Influenza Vaccine), and AFLURIA® (Influenza Vaccine)?

FLUAD is a vaccine that helps protect people aged 65 years and older from the flu.

FLUCELVAX and AFLURIA are vaccines that help protect people aged 6 months and older from the flu.

Vaccination with any of these may not protect all people who receive the vaccine.

Who should not receive FLUAD, FLUCELVAX, or AFLURIA?

You should not receive FLUAD nor AFLURIA if you have a history of severe allergic reactions (e.g., anaphylaxis) to any component of the vaccine, including egg protein, or to a previous influenza vaccine.

You should not receive FLUCELVAX if you have a history of severe allergic reactions (e.g., anaphylaxis) to any component of the vaccine.

Before receiving FLUAD, FLUCELVAX, or AFLURIA, tell your healthcare provider about all medical conditions, including if you:

  • have ever had Guillain-Barré syndrome (severe muscle weakness) within six weeks after getting a flu vaccine. The decision to give any flu vaccine should be made by your healthcare provider, based on careful consideration of the potential benefits and risks
  • have problems with your immune system or are taking certain medications that suppress your immune system, as these may reduce your immune response to the vaccine
  • have ever fainted when receiving a vaccine

What are the most common side effects of FLUAD, FLUCELVAX, and AFLURIA?

  • pain, tenderness, redness, itching, bruising, and/or swelling where the vaccine was given
  • headache
  • extreme tiredness
  • muscle aches
  • feeling unwell (malaise)

Additional side effects seen in children include:

  • raised hardened area where the vaccine was given
  • changes in eating habits/loss of appetite
  • sleepiness
  • irritability
  • diarrhea

These are not all the possible side effects of FLUAD, FLUCELVAX, and AFLURIA.

You can ask your healthcare provider for more information and for advice about any side effects that concern you.

What do I do if I have side effects?

Report any severe or unusual side effects to your healthcare provider.

To report SUSPECTED ADVERSE REACTIONS, contact CSL Seqirus at

1-855-358-8966 or VAERS at 1-800-822-7967 or www.vaers.hhs.gov.

Before receiving any of these vaccines, please see the full US Prescribing Information for FLUAD, FLUCELVAX, or AFLURIA. You can ask your healthcare provider or pharmacist for information about FLUAD, FLUCELVAX, or AFLURIA that is written for healthcare professionals
 

USA-CRP-25-0015

MEDIA CONTACT

Greg Healy

Senior Director, Corporate and External Affairs, CSL

+1 610-906-4564

Greg.Healy@cslbehring.com

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REFERENCES

1 CDC. Who Needs a Flu Vaccine. Retrieved from: https://www.cdc.gov/flu/vaccines/vaccinations.html. Accessed July 2025.

2 CDC. People at Increased Risk for Flu Complications. https://www.cdc.gov/flu/highrisk/index.htm. Accessed July 2025.

3 Centers for Disease Control and Prevention (CDC). Flu Vaccination Coverage. Retrieved from: https://www.cdc.gov/fluvaxview/coverage-by-season/2023-2024.html. Accessed July 2025.

4 CDC. Laboratory-Confirmed Influenza Hospitalizations. Retrieved from: https://gis.cdc.gov/GRASP/Fluview/FluHospRates.html. Accessed July 2025.

5 CDC. Weekly US Influenza Surveillance Report: Key Updates for Week 20, ending May 17, 2025. Retrieved from: https://www.cdc.gov/fluview/surveillance/2025-week-20.html. Accessed July 2025.

6 CDC. Weekly US Influenza Surveillance Report: Key Updates for Week 26, ending June 28, 2025. Retrieved from: https://www.cdc.gov/fluview/surveillance/2025-week-26.html. Accessed July 2025.

7 FLUCLEVAX. Package Insert. CSL Seqirus Inc.

8 FLUAD. Package Insert. CSL Seqirus Inc.

9 Grohskopf LA, Ferdinands JM, Blanton LH, Broder KR, Loehr J. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2024–25 Influenza Season. MMWR Recomm Rep 2024;73(No. RR-5):1–25. DOI: http://dx.doi.org/10.15585/mmwr.rr7305a1.

10 AFLURIA. Package Insert. CSL Seqirus Inc.

11 CDC. About Influenza. Retrieved from: https://www.cdc.gov/flu/about/index.html. Accessed July 2025.

12 CDC. Preliminary Estimated Flu Disease Burden 2024-2025 Flu Season. Retrieved from: https://www.cdc.gov/flu-burden/php/data-vis/2024-2025.html. Accessed July 2025.