Background Viral and host immune kinetics during acute COVID-19 and after remission of acute symptoms need better characterization . Methods SARS-CoV-2 RNA, anti-SARS-CoV-2 IgA, IgM, and IgG antibodies, and pro-inflammatory cytokines were measured in sequential samples among hospitalized COVID-19 patients during acute infection and 6 months following diagnosis . Results 24 laboratory-confirmed COVID-19 patients with mild/moderate and severe COVID-19 were included . Most were males 83%, median age of 61 years . 21% were admitted to the ICU and 8 of them (33.3 %) met criteria for severe COVID-19 disease . A delay in SARS-CoV-2 levels decline during the first 6 days of follow-up and viral load persistence until month 3 were related with severe COVID-19, but not viral load levels at the diagnosis . Higher levels of anti-SARS-CoV-2 IgA, IgM, IgG and the cytokines IL-6, IL-8 and MIP-1β at the diagnosis time were related with severe COVID-19 outcome . Higher levels of MIP-1β, IL-1β, MIP-1α and IFN-γ were observed at month 1/3 during mild/moderate disease compared to severe COVID-19 . IgG persisted at low levels after 6 months of diagnosis . Conclusions Higher concentrations of IgA, IgM, and IgG, and IL-6, IL-8 and MIP-1β are identified as early predictors of COVID-19 severity, but not SARS-CoV-2 RNA levels at diagnosis.