Recent research evidence shows that levels of antibodies acquierd post vacunation against SARS-Cov-2 decrease over time as well as the efficacy to control the infection, additionally in a multicenter study carried out in 2020 were evidenced differences in the time it took to decrease the antibodies according to the type of vaccine, defined as mRNA or other types of vaccine.

In this study , the variation of the SARS-Cov-2 antibody levels in patients from Valle de Aburrá will be correlated according to the COVID-19 vaccine received.

After being informed about the study, all patients giving written informed consent will undergo a serial IgM -IgG COVID-19 antibodies blood test and SARS-Cov-2 PCR by nasopharingeal swab, that will be taken at the beginning of the study and mensually for two months.

During the study will be done an active search for SARS-CoV-2 infections in the vaccinated people cohort, and if it is posible to characterize the variant of SARS-CoV-2 in participants previously vaccinated against this pathogen.

The main objective of this study is to describe the pattern of antibodies blood test based in the type of vaccine and correlated the pattern of antibodies SARS-Cov-2 levels in a population of Valle de Aburrá.

Inclusion Criteria:

• Adult over 18 years old
• The vaccinated patients to be included must have received a complete vaccination scheme for COVID-19 according to the Ministerio de Salud y Protección Social de Colombia
• SARS-CoV-2 infection in the last 2 months, verified by rtPCR test

Exclusion Criteria:

• Immunocompromised patients
• Immunosuppressive treatments, chemotherapy or antiretroviral therapy
• Outpatient anticoagulant therapy
• For vaccinated people (groups 1 and 2): if have had COVID-19 infection in the last 6 months

People with a fully vaccination scheme for COVID-19 according to the Ministerio de Salud y Protección Social de Colombia and patients diagnosed with SARS-CoV-2 infection in the last 60 days, without matter vaccination status against SARS-CoV-2.