The White House on Tuesday held a summit with vaccine makers and scientists as it pushed for "next generation" Covid-19 vaccines that offer broader and more durable protection against the virus.
While current vaccines continue to confer strong protection against serious illness from Covid, the ongoing evolution of the virus has reduced their effectiveness against infection and transmission.
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said the efforts would be based on two pillars: "pan-coronavirus" vaccines that would stand up to variants and "mucosal" vaccines that are delivered nasally to stop the virus where it enters.
"The goal of that is not only to protect against disease, but to protect against acquisition, and by acquisition, transmission," he said of the intranasal vaccine.
Achieving a pan-coronavirus vaccine might be possible by taking pieces of different variants, which is called a "mosaic" approach.
Both ideas are far off from realization.
Nasal vaccines are being tested in mice, where they have shown promise, while vaccine developers Pfizer and BioNTech have announced they will work towards trials for universal coronavirus vaccines.
In a commentary for Science magazine, scientists Eric Topol and Akiko Iwasaki argued that a new funding program for next generation vaccines was needed, along the lines of Operation Warp Speed, which funneled $10 billion into vaccine development early in the pandemic.
"The objective of breaking the chain of transmission at the individual and population level will put us in a far better position to achieve containment of the virus, no less reducing the toll of sickness and long Covid," they said.