Early research raised hopes for a vaccine that would protect against all respiratory pathogens simultaneously, rather than just a single disease such as influenza.
Traditional vaccines prime the immune system for specific targets, such as a protein on a virus. The new system, delivered via nasal spray, boosts the system’s communication signals, putting it on a higher alert. In mice, the spray reduced infection rates from viruses including flu and SARS-CoV-2, as well as common bacteria such as Staphylococcus aureus, for about three months.
Vaccinologists were cautiously excited, although there remain reasons to be skeptical: Mice’s bodies are apparently somewhat different from humans’, and keeping the immune system on permanently high alert could have downsides.