Right, that's been mentioned elsewhere.

A new area of research has opened up. This approach may be more useful for treatment than prevention. It's not really a vaccine; it's more like an induced vaccine response. Keeping the immune system in that state full time might be a problem. But after an infection, that's what's wanted.

I think that "vaccine" is really not the right word to use for this; they sound as different as bandages and blood transfusions. But if it works as advertised, it could be useful if used in the right situation.

I do wonder if the kind of people who got vaccinated 10 times against Covid-19 will end up trying to get a sniff of this every month? Kind of like how we overuse antibiotics in cleaners. It seems like it would be best if saved for an "oh shoot" kind of situation.