wow that's incredible news that you're feeling more immune than ever ;)
yes... it can be really annoying! i would definitely suggest just growing your own. as stipulated in the article, it is so easy. they also grow in the wild. i'm not sure where you live, but you can find them there as well. you could also probably find a really well made product somewhere on etsy searching for elderberry syrup. a ton of great herbalists on there. a little more pricey perhaps, but a good product :)
I had never thought to find homemade on etsy! great idea. I'm on Cape Cod and have seen plants with similar berries and got kind of excited but the stems are not woody and eating those i think might have the opposite result of what I'd like. haha