Yep, those are tricky. They certainly seem contagious. What I can briefly say in this forum is that these are childhood "upgrades" and detoxification events. All rashes, pox, mumps, bumps, etc. are a result of the body pushing toxins out through its largest organ - the skin. Small Pox is the most obvious example of this.

The reason these events sometimes appear contagious is similar to how and why people come into resonance when they are together. A simple example is women who live together for a few months and their monthly periods get synced up right around the same time.

Whatever the "cause" of this syncing, it isn't due to the idea of contagion. The child who got chicken pox or measles had toxins in their system, and the body was finally capable of releasing them. Other kids in his vicinity are frequently going to have the same basic toxins, sharing space, rooms, air, food, etc. The reason some kids don't get the same is not because they have a better immune system (which doesn't really exist BTW), but rather, they either weren't exposed to the same toxins, and/or were better able to detoxify them previously.

Read Lanka's paper. He authoritatively points out that the seminal "Measles Virus" study and scientific efforts were laughably never even close to proving diddly squat.

And yes, apply all of the above to influenza/flu.