RESEARCH TRIANGLE PARK – Flu vaccine producer Seqirus will work with the U.S. government to develop two vaccine candidates to combat future pandemics.

The company – one of the world’s largest influenza vaccine manufacturers – operates a massive plant in Holly Springs where development of the new therapies will be housed. The site produces a portfolio of flu vaccines for people of all ages – from children as young as six months to adults 65 years old and up.

Seqirus’ multi-year contract, totaling $34.95 million, is with the Biomedical Advanced Research and Development Authority (BARDA). BARDA is a unit within the Department of Health and Human Services. Under the agreement, Seqirus will develop and measure the safety and effectiveness of two A(H2Nx) flu virus vaccine candidates.

The first will use a combination of cell-based and adjuvant (enhanced immune response) technologies that build on AUDENZ, the company’s adjuvanted, cell-based influenza vaccine. AUDENZ was approved in 2020 for pandemic use. This technology replaces traditional egg-based manufacturing by growing influenza vaccine in cells rather than eggs.


Seqirus’s parent company, CSL, acquired Novartis in 2015, and announced plans to add a $140 million expansion and 120 jobs to the Holly Springs site. (Photo Courtesy of Seqirus)

The second vaccine candidate will deploy the company’s next-generation self-amplifying mRNA (sa-mRNA) platform. The COVID-19 pandemic has recently brought messenger RNA (mRNA) into prominence. Both Pfizer and Moderna gained approval to use the new technology in their coronavirus vaccines.

mRNA therapies help the body protect itself against infectious disease by teaching cells to trigger an immune response. And they leave a blueprint to recognize and fight future infection.

Seqirus’ self-amplifying mRNA – the next generation of the technology – also instructs the body to replicate mRNA, which increases the amount of protein produced. And this enables manufacturers to potentially develop more-effective, smaller-dosage vaccines that cause fewer side effects.

The Holly Springs plant, built in 2009 through a public-private partnership with BARDA, was designed to rapidly increase production of flu shots in response to serious flu outbreaks or a flu pandemic. The $1 billion-plus facility can supply more than 150 million doses of vaccine to support a pandemic response.

The North Carolina Biotechnology Center was involved in recruiting the manufacturing center, which is located on 185 acres and incorporates seven buildings connected to a central corridor. It encompasses 475,000 square feet – an area equal in size to about 10 football fields. The Holly Springs site employs close to 900 people.

Seqirus flu vaccine plant in Holly Springs

“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 David Sehgal, executive director of manufacturing and head of the Holly Springs site. “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.”

While there currently is no circulating strain of A(H2Nx) influenza in humans, H2Nx viruses continue to replicate in bird populations. And our immunity isn’t adequate to block their epidemic spread when the viruses cross over to people. The most recent outbreak of A(H2Nx) triggered the 1957 Asian flu pandemic, which caused more than one million deaths globally, including 116,000 in the U.S.

Seqirus has agreements with 30 governments worldwide to provide strain-matched vaccines in the event of an influenza pandemic. In this county, the company and its legacy businesses have worked with the U.S. government to develop vaccines against 12 different pre-pandemic strains since 2006.

Seqirus was formed in 2015 after its Australian parent company, CSL Ltd., purchased the Holly Springs plant and related technology from Novartis. Its product portfolio includes four licensed adjuvanted pandemic and pre-pandemic influenza vaccines. The company also has production facilities in the U.K. and Australia.

CSL is a leading global biotechnology company that got its start in 1916. Its two businesses, CSL Behring and Seqirus, provide life-saving products to more than 100 countries and employ close to 27,000 people.

(C) N.C. Biotech Center