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Seqirus Awarded U.S. Government Contract to Develop Two Pandemic Influenza Vaccines

• Seqirus will develop and evaluate two influenza A(H2Nx) virus vaccine candidates in support of U.S. government pandemic preparedness objectives
• Company will utilize its combination of cell-based and adjuvanted influenza vaccine technologies, as well as its next-generation self-amplifying mRNA platform
• Multi-year contract with Biomedical Advanced Research and Development Authority (BARDA) builds on longstanding, successful public-private partnership to provide rapid vaccine manufacturing response in an influenza pandemic


Seqirus, a global leader in influenza prevention and a business of CSL Limited (ASX:CSL), today announced that the Biomedical Advanced Research and Development Authority (BARDA), a division of the Office of the Assistant Secretary for Preparedness and Response (ASPR) within the U.S. Department of Health and Human Services (HHS), has selected Seqirus to develop two influenza A(H2Nx) virus vaccine candidates for assessment in a Phase 1 clinical study with the goal of helping to safeguard communities in the event of an influenza pandemic.1  

Under terms of the multi-year, $34.95 million agreement, Seqirus will provide clinical development services to evaluate the safety, immunogenicity and dose-sparing capability of two influenza A(H2Nx) vaccine candidates:1 

  • The first candidate will utilize a combination of cell-based and adjuvanted technologies, building on Seqirus’ highly flexible combination platform technology used by AUDENZ™ (Influenza A(H5N1) Monovalent Vaccine, Adjuvanted), the first-ever adjuvanted, cell-based influenza vaccine, which was approved by the U.S. Food and Drug Administration in 2020 for use in a pandemic.2 
  • The second candidate will utilize Seqirus’ next-generation self-amplifying mRNA (sa-mRNA) platform, which has demonstrated promise as compared to more traditional influenza vaccine technologies in preclinical research.3  

“As a global leader in pandemic influenza preparedness, Seqirus understands the vital role of global partnerships in preparing for the unpredictable, ever-present threat of pandemic influenza, which, according to the World Health Organization, is a matter of ‘when,’ not ‘if,’” said Marc Lacey, Executive Director, Pandemic Response Solutions, Seqirus.4  “Seqirus is uniquely positioned to use our pandemic influenza vaccine expertise, flexible platform technologies and innovative research capabilities to reliably meet the needs of the U.S. government in such a critical capacity. We are proud to be a trusted partner in support of BARDA’s pandemic preparedness objectives.” 

Seqirus to Utilize Proven and Promising Platform Technologies

Seqirus’ global product portfolio includes four licensed adjuvanted pandemic and pre-pandemic influenza vaccines, three of which use its proprietary MF59® adjuvant intended to enhance an individual’s immune response and potentially be antigen-sparing in the event of a pandemic outbreak.2,5,6,7  

Combining Seqirus’ adjuvant technology with its cell-based manufacturing platform may improve protection even further by potentially providing a better match to the circulating virus strain – setting the stage to meet the public health challenge of an influenza pandemic.8 

Additionally, Seqirus’ sa-mRNA platform, the next-generation version of today’s mRNA technology, builds on traditional mRNA technology by also instructing the body to replicate mRNA, amplifying the amount of protein made.3 This could enable Seqirus to potentially develop more effective vaccines with a smaller dosage and with lower rates of reactogenicity, underscoring the application in both pandemic and seasonal settings.3 In preclinical research, sa-mRNA technology demonstrated the potential to raise stronger cellular responses and generate significantly higher antibody titers at the same dose level as mRNA.3

Both cell-based and sa-mRNA technology are steps forward in achieving key objectives found in the U.S. National Influenza Vaccine Modernization Strategy, which focuses on strengthening and diversifying influenza vaccine development, manufacturing and supply chain, and promoting innovative approaches and use of new technologies to detect, prevent and respond to influenza.9 

Seqirus and BARDA Build on Longstanding, Successful Partnership

Seqirus has a longstanding partnership with BARDA. The company’s cell-based manufacturing facility in Holly Springs, N.C., the first such domestic facility, was built through a public-private partnership established in 2009 with BARDA.10 It utilizes a highly scalable method of production and is currently positioned to deliver up to 150 million influenza vaccine doses to support an influenza pandemic response.10  

“As the largest cell-based influenza vaccine producer in the world, Seqirus’ Holly Springs facility makes a significant – and growing – contribution to the supply of seasonal influenza vaccines in the U.S., reflecting our ability to protect public health on an annual basis and underscoring our preparedness to respond to future influenza pandemics,” said Dave Sehgal, Executive Director, Manufacturing and Holly Springs Site Head, Seqirus. “We remain committed to working with BARDA and other global partners on the front line of public health in mitigating the potentially devastating effects of another influenza pandemic.” 

HHS continuously monitors emerging infectious disease risk and prepares to respond to the threat of novel emerging infectious disease outbreaks in the United States.11 The National Pre-Pandemic Influenza Vaccine Stockpile (NPIVS) has been established and satisfies requirements for vaccine and adjuvants to address influenza viruses that are assessed to be the highest risk for human infection.12  

While there is no currently circulating strain of influenza A(H2Nx) virus in humans, H2Nx strains continue to circulate in avian reservoirs and triggered the 1957 pandemic, which caused an estimated 1.1 million deaths worldwide and 116,000 deaths in the United States.13 Population immunity to H2 viruses is insufficient to block epidemic spread, and currently stockpiled influenza A(H5Nx) and A(H7N9) virus vaccine antigens will provide no protection in the case of any emerging influenza A(H2Nx) virus.14  

Seqirus holds agreements with 30 governments worldwide to provide a strain-matched vaccine in the event of an influenza pandemic. In partnership with the U.S. government, Seqirus and its legacy companies have developed vaccines against 12 different pre-pandemic strains since 2006, including H5, H7 and H1. This agreement adds H2 to this arsenal.

About Seasonal Influenza
Influenza is a common, contagious seasonal respiratory disease that may cause severe illness and life- threatening complications in some people.15 Influenza can lead to clinical symptoms varying from mild to moderate respiratory illness to severe complications, hospitalization and in some cases, death.15 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.15 Estimates from the CDC report that during the 2019/20 influenza season, there were an estimated 405,000 influenza-related hospitalizations in the U.S.16 The CDC recommends annual vaccination for individuals aged 6 months and older, who do not have any contraindications.17  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.17 The CDC recommends that people get vaccinated by the end of October.17 For non-pregnant adults, getting vaccinated too early (for example, in July or August), should be avoided, unless there is concern that later vaccination may not be possible, as it can be associated with reduced protection against influenza infection later in the flu season.17

About Pandemic Influenza
Pandemic influenza, is a contagious airborne respiratory disease which is unpredictable in timing and severity.18 The risk of influenza-associated morbidity and mortality is greater with pandemic influenza than with seasonal influenza because there is likely to be little or no pre-existing immunity to the virus in the human population.19 Four influenza pandemics have occurred over the past century, with the 1918 pandemic being the most severe in recent history, estimated to have killed up to 50 million people worldwide.20 According to the WHO, a novel influenza A virus such as the highly pathogenic avian A(H5N1) strain can cause severe disease and have a high mortality rate.21 If the influenza A(H5N1) virus were to change and become easily transmissible from person to person while retaining its capacity to cause severe disease, the consequences for public health could be catastrophic, with an estimated 60% mortality rate.21

About Seqirus
Seqirus is part of CSL Limited (ASX: CSL). As one of the largest influenza vaccine providers in the world, 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, 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 enables us to identify, develop and deliver innovations so our patients can live life to the fullest. For more information about CSL Limited, visit

For more information visit and

Intended Audience
This press release is issued from Seqirus USA Inc. 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 Seqirus products may vary from country to country. Please consult your local regulatory authority on the approval status of 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.

AUDENZ™ (Influenza A(H5N1) Monovalent Vaccine, Adjuvanted)
Important Safety Information


AUDENZ is an inactivated vaccine indicated for active immunization for the prevention of disease caused by the influenza A virus H5N1 subtype contained in the vaccine.  
AUDENZ is approved for use in persons 6 months of age and older at increased risk of exposure to the influenza A virus H5N1 subtype contained in the vaccine.

Use in persons 6 months through 17 months of age is approved under accelerated approval based on the immune response elicited by AUDENZ. Continued approval for use in this age group may be contingent upon verification and description of clinical benefit in a confirmatory trial.

History of a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine, or after a previous dose of an influenza vaccine.


  • Hypersensitivity reactions can occur. Appropriate medical treatment and supervision must be available to manage possible anaphylactic reactions following administration of the vaccine.
  •  If Guillain-Barré syndrome has occurred within 6 weeks of receipt of a prior influenza vaccine, the decision to give AUDENZ should be based on careful consideration of potential benefits and risks. 


  • In adults 18 through 64 years of age, the most common (≥ 10%) solicited local and systemic reactions reported in clinical trials were injection site pain (64%), fatigue (25%), headache (25%), malaise (22%), myalgia (14%), arthralgia (10%), and nausea (10%). 
  • In adults 65 years of age and older, the most common (≥ 10%) solicited local and systemic reactions reported in clinical trials were injection site pain (36%), fatigue (20%), malaise (16%), headache (16%), and arthralgia (10%). 
  • In infants and children, 6 months through 5 years of age, the most common (≥ 10%) solicited local and systemic reactions reported in clinical trials were tenderness (56%), irritability (30%), sleepiness (25%), change in eating habits (18%), and fever (16%). 
  • In children 6 through 17 years of age, the most common (≥ 10%) solicited local and systemic reactions reported in clinical trials were injection site pain (68%), myalgia (30%), fatigue (27%), malaise (25%), headache (22%), loss of appetite (14%), nausea (13%), and arthralgia (13%).   

To report SUSPECTED ADVERSE REACTIONS, contact Seqirus at 1 855 358 8966 or VAERS at 1 800 822 7967 or

Before administration, please see the full Prescribing Information for AUDENZ.

AUDENZ and MF59® are registered trademarks of Seqirus UK Limited or its affiliates. 


Maria Tortoreto 
+1 (201) 248-5208


This project has been funded in whole or in part with Federal funds from the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under contract numbers HHSO100201800004I and HHSO100200900101C.

AUDENZ™ (Influenza A(H5N1) Monovalent Vaccine, Adjuvanted) [package insert]. Holly Springs, NC: Seqirus Inc; 2020.

Vigel, B., Lambert, L., Kinnear, E., et al. (2018). Self-Amplifying RNA Vaccines Give Equivalent Protection against Influenza to mRNA Vaccines but at Much Lower Doses. American Society of Gene & Cell Therapy. 

World Health Organization (WHO). The next flu pandemic: a matter of ‘when’, not ‘if.’ Retrieved from: Accessed October 2021.

Aflunov® Package Insert. 2020. 

Panvax® Package Insert. 2008.

FOCLIVIA® Product Monograph, January 7, 2021.

CDC. (2021). Cell-Based Flu Vaccines. Retrieved from: Accessed October 2021.

Public Health Emergency. (2020). Vision and Strategic Objectives. Retrieved from: Accessed October 2021.

10 This project has been funded in whole or in part with Federal funds from the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under contract numbers HHSO10020060001F2C, HHSO100200700030C, HHSO100200900101C and HHSO100201200003I.

11 U.S. Department of Health & Human Services. (HHS). National Notifiable Diseases Surveillance System Modernization Initiative. Retrieved from: Accessed October 2021.

12 HHS. Pandemic Influenza Vaccine Stockpile Program. Retrieved from: Accessed October 2021.

13 CDC. (2019). 1957-1958 Pandemic (H2N2 virus). Retrieved from: Accessed J October 2021.

14 Babu, T., Perera, R., Wu, J, et al. (2018). Population Serologic Immunity to Human and Avian H2N2 Viruses in the United States and Hong Kong for Pandemic Risk Assessment. The Journal of Infectious Diseases. 

15 CDC. (2021). Key Facts about InfluenzA(Flu). Retrieved from: Accessed October 2021.

16 CDC. (2021). Estimated Influenza Illnesses, Medical visits, Hospitalizations, and Deaths in the United States — 2019–2020 Influenza Season. Retrieved from: Accessed October 2021.

17 Centers for Disease Control and Prevention (CDC). (2021). Who Needs a Flu Vaccine and When. Retrieved from: Accessed September 2021.

18 CDC. (2016). Pandemic Basics. Retrieved from: Accessed October 2021.

19 WHO. (2021). How pandemic influenza emerges. Retrieved from: Accessed October 2021.

20 WHO. (2017). Pandemic Influenza Risk Management: A WHO guide to inform and harmonize national and international pandemic preparedness and response. Retrieved from:;jsessionid=4421F16879D2F8B96481F8D0C745C7F3?sequence=1. Accessed October 2021.

21 (WHO). (2012). Influenza: H5N1. Retrieved from: Accessed October 2021.