And so that will create a much quicker, a much more rapid response with a shorter latent period because of those memory B cells. In addition, the amount of antibodies that is formed will be much greater. And actually we're going to need a much lower concentration of antigen to elicit a secondary response than to elicit a primary response. That's another difference between the primary and the secondary responses. So let's conclude by comparing and contrasting these two different types of responses. So for the primary response we have a relatively long latent period.