So to answer this question they did some really cool science. So let’s talk about the methods they used in this study. The first thing is that they wanted to be able to compare these antibodies before and after getting sick. That’s the only way they would be able to tell if our immune system memory was decreased by doing a before and after comparison. So what they did is they found a school in the Netherlands where vaccination was not required. So they took 82 kids and they took blood samples. And then during the next outbreak of measles they monitored the kids. And 77 out of the 82 actually got sick. Then two to three months later they took blood samples again. Then they compared all these blood samples to a variety of controls that we’ll talk about when we talk about our results. Then the last thing our researchers did was they actually experimentally tested this idea on monkeys. So they actually gave the monkeys the measles and measured their antibodies afterwards.