More than one hundred years ago the Irish believed an extract from a red seaweed could cure sick cows, and humans with colds and flu's. In terms of early treatment modern medical science is slowly catching up with 19th Century farmers. In a small trial this year medical workers were 80% less likely to catch Covid if they were using a nasal spray with the "Irish Moss" carrageenan extract. It's only a case of 2 out of 200 catching Covid in the test group, compared to 10 out of 200 in the placebo group, so the "80%" is a rubbery number, but it was a randomized control trial, and there are other lab test results which suggest the effect is real.
And because we recently figured out it was useful against common colds and influenza's, nasal sprays with this common safe food additive are already on sale at the Chemist. So you can pop in and get one before Christmas Parties.
Carrageenan or "Irish Moss" is a polysaccaride gel from a red seaweed. It works by gumming things up for quite a few viruses — basically getting in the way and trapping them in the gel. The idea is to squirt it up your nose three or four times a day to make it hard for a virus to get in. Not as much fun as a glass of champers, but more fun than a head cold.