Since trials were carried out some months ago, it has gone very quiet on this. Putting swabs up noses and down throats can be distressing for some. Just spitting down a tube would be far easier, and quicker.
I am also puzzled that vitamin D and zinc supplements are not ever mentioned. Vitamin D supplements are very low cost and have strong evidence of effectiveness. I have never, ever, heard vitamin D supplements mentioned ever. Why not? If this is a "quick win" why are we not encouraged to take these? I know of several friends who are taking these.