But for the secondary response we have a relatively short latent period. So that means our secondary response is much quicker to take into effect as a result of those antibodies already being present inside our blood. Now, for the case of the primary, we form a relatively low concentration, peak concentration of antibodies. But here we form a much larger peak concentration of antibodies. So peak simply means the highest value of these particular hills. Now, notice that during our decline phase we dropped to very low undetectable value in the primary case.