The main objective of the study is to describe the immune response to the SARS-CoV-2 virus among patients with confirmed Covid-19 disease in terms of antibody levels, differences in response related to epidemiologic and clinical characteristics, duration of the antibody response and protective efficacy.~Of particular interest is the demonstration of seroconversion with neutralizing antibodies, their duration during a follow-up of two years and their ability to prevent subsequent infections and disease. If antibodies are demonstrated to protect against subsequent infections and that protection is long-lasting, this can be instrumental for the reincorporation of immune individuals into normal life and economic activities.~Additional secondary objectives include determination of population-prevalence of past infection and assessment of genetic determinants of the immune response and the clinical presentation of the disease. Finally, we will investigate secondary transmission in a sample of household contacts of Covid-19 cases.~This study will provide important information to define the use of specific types of antibodies and their potential utility for diagnosis, ascertainment of previous exposure and acquired immunity. The effort is being conducted by the Caja Costarricense de Seguro Social, the Costa Rican Ministry of Health and the Agencia Costarricense de Investigaciones Biomédicas (ACIB), in collaboration with the US National Cancer Institute, the US National Institute of Allergy and Infectious Diseases and the German Cancer Research Center and will be supervised by the Ethical Committee of the CCSS according to local regulations.
Describe the immune response of patients affected by SARS-CoV-2, including an assessment of the types of antibodies elicited by the infection, specifc antibody titers for the different isotypes, evolution of the antibody response over time, protective efficacy and immune correlates of protection.~investigate genetic determinants of Covid-19 and of the imune response to this condition.~Finally, the study will investigate secondary infection rate and its determinants among household contacts of Covid-19 patients.