HOLLY SPRINGS, N.C., Sept. 29, 2026 /PRNewswire/ — CSL Seqirus, a business of CSL (ASX: CSL), today announced expanded availability of influenza vaccine in the United States following the successful completion of its 2026/27 manufacturing campaign.

With the majority of customer orders already shipped and deliveries expected to be completed ahead of schedule, the company has additional doses readily available to support customers and public health vaccination efforts throughout the influenza season.

The update comes amid reported supply challenges affecting portions of the U.S. and global influenza vaccine market following implementation of the three strain changes recommended by the World Health Organization (WHO) for the upcoming season’s vaccine.

“We recognize the critical role reliable vaccine supply plays in supporting seasonal influenza vaccination and broad stakeholder efforts to improve vaccination rates,” said Stefan Merlo, Vice President, Commercial Operations, CSL Seqirus.

“While supply challenges have been reported elsewhere in the market, CSL Seqirus has continued to deliver vaccines to customers nationwide ahead of schedule.”

As one of the largest influenza vaccine manufacturers with U.S.-based manufacturing capabilities, CSL Seqirus successfully implemented the WHO-recommended strain changes as part of its annual manufacturing campaign. Despite the additional manufacturing complexity introduced by these updates, the company completed its manufacturing campaign ahead of schedule.

“Influenza vaccine manufacturing is a highly complex biological process, and different virus strains can present unique challenges throughout production,” said Chris Larkins, Senior Vice President, Global Manufacturing Operations, CSL Seqirus. “The successful implementation of this season’s strain updates reflects the expertise of our teams and the strength of our manufacturing network.”

In a number of cases where supply shortages have emerged in the broader market, CSL Seqirus has worked with customers and public health authorities to help maintain access to influenza vaccination. The company continues to have vaccine available should additional public health needs arise during the season.

Influenza vaccine production involves multiple interconnected stages, including strain selection, manufacturing, quality and potency testing, regulatory review and release, fill-finish operations and distribution. Delivering millions of vaccines reliably each season requires scientific expertise, manufacturing capability and operational execution working together effectively.

About Seasonal Influenza 
Influenza is a common, contagious seasonal respiratory disease that may cause severe illness and life-threatening complications in some people.¹ Influenza can lead to clinical symptoms varying from mild to moderate respiratory illness to severe complications, hospitalization and in some cases, death.¹ 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.² Preliminary estimates from the Centers for Disease Control and Prevention (CDC) report that during the 2025/26 influenza season, there were an estimated 390,000-800,000 influenza-related hospitalizations in the U.S.³ The CDC recommends annual vaccination for individuals aged six months and older, who do not have any contraindications.⁴ 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.⁴ The CDC recommends that most people get vaccinated by the end of October.⁴

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 and response. With state-of-the-art production facilities in the US, the UK 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 https://www.cslseqirus.us/.

Intended Audience 
This press release is issued from CSL Seqirus in Holly Springs, North Carolina, 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.

Media Contact
Melanie Kerin
melanie.kerin@seqirus.com
+44 7345 433 260

USA-CRP-26-0008

¹ CDC. Key Facts about Influenza. Retrieved from: https://www.cdc.gov/flu/vaccines/keyfacts.html. Accessed September 2026.
² CDC. About Influenza. Retrieved from: https://www.cdc.gov/flu/about/index.html. Accessed September 2026.
³ CDC. Preliminary Estimated Flu Disease Burden 2025-2026 Flu Season. Retrieved from: https://www.cdc.gov/flu-burden/php/php/data-vis/2025-2026.html. Accessed September 2026.
⁴ CDC. Who Needs a Flu Vaccine and When. Retrieved from: https://www.cdc.gov/flu/vaccines/vaccinations.html. Accessed September 2026.

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SOURCE CSL Seqirus