Oh, dear old BBC, presenting long-known facts as if they were startling news.
The implications for healthcare could mean that drugs need to be given at certain times of day in order to make them more effective
Yes, we've all known that for years. Go and read The Body Clock Guide to Better Health, and follow up its references, if you want to know more.
I've had my body clock all over the place (Non-24 Sleep-Wake Cycle), and I've managed to wrestle it back to normal using light and darkness therapies, and I'm trying to think whether it affected my immunity in any noticeable way. Not that I recall, but it's not actually one of the more obvious things for me. The obvious differences were in things like pain levels, which go shooting up when I sleep badly, and my digestive tract not being able to settle down to a regular schedule. It's entirely possible that I get fewer colds now than when my body clock was crazy, but I can't remember. There are so many factors involved with catching a cold, and the biggest is probably that I now live with my partner, who works in retail, and is thus likely to bring home one or two colds a year. Anyway, isn't there a possibility that people with ME actually catch fewer colds due to an overactive immune system?