INTENDED FOR MEDIA AND BUSINESS INVESTORS ONLY

Summit, New Jersey, USA | 17 October 2025 – CSL Seqirus, a business of CSL (ASX:CSL) today announced that it will be presenting 14 abstracts at the European Scientific Working group on Influenza conference (ESWI 20-23 October) highlighting the value of enhanced seasonal influenza vaccines and reinforcing the vital role they play in protecting public health.

“ESWI is a critical moment in time for the seasonal influenza vaccine community to come together and discuss the latest research in the infectious diseases space,” said Pepe Meseguer Perez, Spain and Iberian Cluster Head at CSL Seqirus. “Our presence at ESWI’s 10^th congress is underpinned by the strength of the data we have submitted. We are excited to welcome the vaccine community to Valencia to share our results.”

Key Data Highlights

Highlights from these abstracts include:

• A Public Health and Comparative Cost Analysis of Enhanced Influenza Vaccination in Adults Aged >65 years Compared to Current Programmes Across the Nordic Regionⁱ
  • 18:00 – 18:30, 21 October
  • Poster number: 238
• Comparable Vaccine Effectiveness of Adjuvanted and High-Dose Influenza Vaccines in Preventing Test-Confirmed Influenza Outcomes, including Hospitalisation, in Overall and High-Risk Older Adults: A Test-Negative Design Study During 2022–2023 and 2023–2024ⁱⁱ
  • 17:30 – 19:00, 22 October
  • Poster number: 153

“The data being presented at ESWI this year will highlight the clear effectiveness of enhanced seasonal influenza vaccines,” said Jonathan Anderson, Executive Medical Director, International Regions (Europe and Asia Pacific), CSL Seqirus. “These data show clearly the benefit enhanced influenza vaccines may have to public health.”

Supporting the Next Generation of Scientists

CSL Seqirus is proud to sponsor the 4th Young Scientist Vaccine Innovation Award, which honours outstanding research by an emerging scientist in influenza vaccine development. The Young Scientist Vaccine Innovation Award ceremony will take place on 23 October, 09:30 – 10:30. CSL Seqirus will also be supporting a Satellite Symposium on 21 October, 16:00 – 17:00, under the theme "Addressing the Evolving Influenza Landscape: A Public Health Imperative.

About Seasonal Influenza 
Influenza is a common, contagious seasonal respiratory disease that may cause severe illness and life-threatening complications in some people. Influenza can lead to clinical symptoms varying from mild to moderate respiratory illness to severe complications, hospitalisation and in some cases, death. Because transmission of influenza viruses to others may occur one day before symptoms develop and up to 5 to 7 days after becoming sick, the disease can be easily transmitted to others. Seasonal influenza is a vaccine-preventable disease which exerts an annual health burden across Europe of up to 70,000 deaths.³

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 utilises 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 portfolio of 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 products to patients in more than 100 countries and employs 32,000 people. Our 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 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.   

FLUAD® (Influenza Vaccine, Adjuvanted)

IMPORTANT SAFETY INFORMATION⁴

What is FLUAD® (Influenza Vaccine, Adjuvanted)?

FLUAD is a vaccine that helps protect people aged 65 years and older from the flu. Vaccination with this may not protect all people who receive the vaccine.

Who should not receive FLUAD?

You should not receive FLUAD 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.

Before receiving FLUAD, 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?

• 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.

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 this vaccine, please see the full US Prescribing Information for FLUAD. You can ask your healthcare provider or pharmacist for information about FLUAD that is written for healthcare professionals

MEDIA CONTACT 
Em Dekonor 
+44 (0)7920500496  
Emmanuella.Dekonor@seqirus.com