Australia will build the southern hemisphere’s largest flu vaccine manufacturing plant in a bid to sure up its response to future pandemics.

The federal government has struck a $1 billion, 12-year deal with CSL-owned subsidiary Seqirus for long-term access to influenza and fever vaccines, as well as life-saving antivenoms.

Under the new agreement, Seqirus will invest $800 million to develop a high-tech vaccine manufacturing facility near Melbourne airport to replace its more than 60-year-old Parkville site.

Works will start next year – creating 520 construction jobs – with the site expected to be fully operational by mid-2026.

While the federal government stumped up the money, the Victorian government played a part in procuring the land.

Seqirus is the only company that makes influenza and Q fever vaccines in Australia, while no other firm in the world produces life-saving antivenoms against 11 poisonous Australian snakes, marine creatures and spiders.

The federal government’s current deal with Seqirus had been due to expire in 2024-25, potentially putting Australia at risk of needing to source critical medical products from overseas.

That will now not be a problem until at least 2036.

Prime Minister Scott Morrison said Australia needed to guard against future threats while also focusing on the health and economic challenges of COVID-19.

“This agreement cements Australia’s long-term sovereign medical capabilities, giving us the ability to develop vaccines when we need them,” he said.

“Just as major defence equipment must be ordered well in advance, this is an investment in our national health security against future pandemics.”

Health Minister Greg Hunt said the new facility would “guarantee” Australia’s security against pandemic influenza for the next two decades.

“This is a major milestone, ensuring that Australia can mass-produce vaccines against future flu pandemics,” he said.