Human trials of a two-in-one jab targeting COVID-19 and the flu are expected to start within months.
A triple-threat vaccine from drug firm Moderna is also in the works, which includes protection against a highly contagious lung infection.
9News spoke exclusively to the company's Chief Medical Officer, who is currently visiting Australia.
Dr Paul Burton, who is based in the US, said a Phase 1 trial of a combination flu and coronavirus vaccine is currently underway.
Moderna plans to have that vaccine ready next year or by early 2024.
"We have a three in one which is covid, flu and something called RSV. These are all respiratory pathogens that kill people young and old every year," he said.
Burton also warned of the latest omicron variants sweeping the globe, including Australia.