Well I'm not agreeing that your co-worker's solution is right, but being
metabolically healthy is key to COVID survival
most who are dying have: Obesity, hypertension, diabetus and such
Elderberries are chockfull of antioxidants such as vitamins A and C and various flavonoids and there are some studis saying it can reduce (not prevent) the lenght of colds/flu..
So there are benefits in being a healthy supplement and providing gut health, but I would not say a specific covid remedy
I'd be a little skeptical of Pineapple juice...as it's tons of sugar
so unless you fresh squeeze it, you are not getting all the said benefits and mostly sugar
it does have some interesting properties and in small doses has lots of pluses