Leyden Labs has raised 40 million euros from the Gates Foundation, EIC Fund, Invest-NL, and ClavystBio to advance its pan-influenza nasal spray through clinical trials.

The Gates Foundation joins as a first-time investor, with a specific mandate to expand access to Leyden’s products in low- and middle-income countries.

The raise brings Leyden Labs’ total funding to over $336M, making it one of the best-capitalised respiratory virus biotechs outside the US.

Flu vaccines have been around for 80 years. They still don’t work well enough for the elderly, the immunocompromised, or anyone exposed to a strain that emerged after the annual reformulation window. Leyden Laboratories thinks a nasal spray can do better, and just closed a €40 million round to prove it.

The Dutch biotech announced the round from the European Innovation Council Fund, Dutch national investment institution Invest-NL, the Bill & Melinda Gates Foundation, and Singapore-linked life sciences investor ClavystBio. The EIC Fund, Invest-NL, and ClavystBio are returning backers. The Gates Foundation joins for the first time.