SincetheoutbreakofaSARSepidemiclastyear,significantadvanceshavebeenmadeonourunderstandingofthemechanismsofinteractionbetweentheSARScoronavirus(CoV)andtheimmunesystem.StronghumoralresponseshavebeenfoundinmostpatientsfollowingSARS-CoVinfection,withhightitersofneutralizingAbspresentintheirconvalescentsera.Thenucleocapsid(N)andspike(S)proteinsofSARS-CoVappeartobethedominantantigensrecognizedbyserumAbs.CD4+TcellresponsesagainsttheNproteinhavebeenobservedinSARSpatientsandanHLA-A2-restrictedcytotoxicTlymphocyteepitopeintheSproteinhasbeenidentified.ItislikelythattheimmuneresponsesinducedbySARS-CoVinfectioncouldalsocausepathologicaldamagetothehost,especiallyinthecaseofproinflammatorycytokines.ThereisalsoevidencesuggestingthatSARS-CoVmightbeabletodirectlyinvadecellsoftheimmunesystem.OurunderstandingontheinteractionbetweenSARS-CoV,theimmunesystemandlocaltissuesisessentialtofuturediagnosis,controlandtreatmentofthisverycontagiousdisease.