FDA Approves Seqirus’ Audenz as Vaccine Against Potential Flu Pandemic

Audenz is the first-ever adjuvanted, cell-based influenza vaccine designed to protect against influenza A (H5N1) in the event of a pandemic.

As the world prepares for a potential coronavirus pandemic, the U.S. government has been busy making preparations for the possibility of a flu pandemic. On Friday, the U.S. Food and Drug Administration (FDA) approved Seqirus’ Audenz, a vaccine for a potential pandemic associated with the H5N1 flu virus.

Audenz is the first-ever adjuvanted, cell-based influenza vaccine designed to protect against influenza A (H5N1) in the event of a pandemic. The novel vaccine combines Seqirus’ MF59 adjuvant and cell-based antigen manufacturing. The vaccine is designed to be rapidly deployed to help protect the U.S. population and can be stockpiled for first responders in the event of pandemic, Russel Basser, chief scientist and head of research and development at Seqirus, told BioSpace in an interview following the approval. Speaking from the company’s North Carolina-based manufacturing facility, Basser said the approval of Audenz is a key advance for the company and the nation in preparation for an influenza pandemic.

Audenz is different from the typical flu virus available each year to protect the populace from seasonal influenza. While a typical flu season can be devastating and result in more than 10,000 deaths and hundreds of thousands of hospitalization rates in the United States, a pandemic would be a catastrophe. A flu virus that becomes a pandemic would be something new that people have yet to encounter, Basser said. It would be catastrophic, potentially killing millions of people and causing untold social and economic wreckage. According to the World Health Organization Global Influence Strategy for 2019-2030, a severe flu pandemic would result in a loss of national economic productivity, as well as severe economic burdens on affected citizens and communities.

“If there was a pandemic, it would be catastrophic,” Basser said. He noted that the Spanish flu outbreak in 1918 involved the H1N1 influenza virus and infected 500 million people around the world. The death toll from that outbreak is estimated at between 50 million and 100 million people. The H1N1 virus is different than the H5N1 virus the Audenz vaccine takes aim at. The H5N1 virus is often called “bird flu” due to its prevalence in avians. These types of flu viruses have been known to spread to humans, but on rare occasions. If the 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 very serious, with an approximate 60% mortality rate, Seqirus said in its announcement.

Audenz was developed with the MF59 adjuvant. Which is believed to enhance an immune response from the body by inducing antibodies against virus strains that have mutated. The adjuvant reduces the amount of antigen required to produce an immune response, increasing the number of doses of the vaccine developed, so that a large number of people can be protected as quickly as possible, Basser said.

Development of Audenz was supported by a partnership with the Biomedical Advanced Research and Development Authority (BARDA), part of the U.S. Department of Health and Human Services. Working with BARDA, Basser said they will be able to stockpile doses of Audenz in case of a pandemic outbreak.

This is part of our commitment to protect the U.S. community at large from a flu pandemic. We are providing vaccines for a stockpile,” Basser said.

BARDA Director Rick Bright said the approval of Audenz will help the country achieve the security goals set by the National Strategy for Pandemic Influenza and the 2019 Executive Order to speed the availability of influenza vaccine.

Audenz isn’t the only flu-preparation that Seqirus has been making. In December, the company released new data that shows Fluad, an adjuvanted trivalent influenza vaccine, was more effective than standard non-adjuvanted trivalent influenza vaccine in reducing the risk of flu- and pneumonia-related hospitalization in patients 65-years-of-age and older.

Seqirus was established in 2015 after Australia-based CSL Limited acquired Novartis’ influenza vaccines business. The company is now one of the largest providers of flu vaccines in the world. The company maintains production facilities in the U.S., the U.K. and Australia.