An Analogy for Herd Immunity
I had a discussion the other day with a fellow massage therapist about, what else?, vaccines. When someone commenting on our discussion said that her office had gotten sick but she hadn't, I said that it was likely either luck or the effects of herd immunity. My colleague then said this to me in an exchange after saying that she, "didn't buy that herd immunity had been proven":
...if herd immunity is so effective, then how is it that so many viruses are seeing a revival when so many others have been immunized against it? Wouldn't the theory for herd immunity say that since so many are vaccinated that the people who haven't been would become immune by exposure to those who have been?This is a real problem when debating. People on the science side just assume that basic ideas like herd immunity are understood when they're not. To clarify, here is a good analogy I came up with to explain it.
Let's say you're a female basketball player. You drive the lane and go up for a jump-shot, but are bumped by another player. Your bra strap breaks. What do you do? The coach calls a time out and you go to the bench with the rest of the team. You explain the situation to the coach, but you can't exactly whip off your shirt right there on the sidelines, exposing yourself to the glares of the creepy sports-fans in the bleachers, so what, then?
Your teammates to the rescue! The other women make a tight circle around you and, in the centre, you are free to take your jersey off to safety pin the strap or just put on a new bra. No worries about exposing yourself to the crowd's stares, you're protected by the other members of the team who are shielding you. They're not worried because they're wearing jerseys and the weirdos can't see anything bawdy on them, so life's good. When the danger of exposure passes, the circle disperses and the previously vulnerable player is safe.
Ok, so replace "creepy stares" with virus, and "jersey" with "vaccine" and you should get it. I realize that the analogy falls apart slightly because if you have a severe allergy and cannot get vaccinated, you never get a "jersey", but that's a minor point when explaining the concept.
Right then, off you go.