The objective of this study is to detect the evidence on the immune response following acute SARS-CoV-2 infections. the study will report the profile of IgG specific antibodies levels to SARS-CoV-2 infection found in recovered coronavirus disease (COVID-19) patients after infection for both symptomatic and asymptomatic patients.

A total of 30 COVID-19 patients for the study will be enrolled. All the patients enrolled were confirmed to be infected with SARS-CoV-2 by RT-PCR assay for nasal and pharyngeal swab specimens.

For the study, serum samples of the 30 patients will be collected and will be investigated for the detection rate for immunoglobulin G (IgG). The first sample will be collected 2 weeks after the second negative RT-PCR assay for nasal and pharyngeal swab specimens and 6 samples will be collected after that for 6 months later; one serum sample tested every month for 6 months after.

The following questions will be addressed:-

1. What proportion of confirmed cases develops specific IgG antibodies to SARS-CoV-2?
2. How long is the duration of detection of serum IgG antibodies and antibody titres over time following infection with SARS-CoV-2?

Inclusion Criteria:

• patients with recent COVID- 19 infection(2 weeks after the second negative RT-PCR assay)

Exclusion Criteria:

• patients on immune-suppressive therapy
• patients with immunological disease

patients attending sohag university hospital and have recent COVID -19 infection