Avicenna J Med Biotech

arij002

Avicenna Journal of Medical Biotechnology

2008-2835 2008-4625

Avicenna Research Institute

ajmb60509

Investigation of Durability of SARS-CoV-2-specific IgG and IgM Antibodies in Recovered COVID-19 Patients: A Prospective Study

Zamani

Mohammad

Ghasemi

Ahmad

Shamshirgaran

Morteza

Ahmadpour

Sajjad

Hormati

Ahmad

Khodadadi

Javad

Varnasseri

Mehran

Amini

Fatemeh

Shayanrad

Amaneh

Younesi

Vahid

Poustchi

Hossein

Shabani

Mahdi

Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences , Tehran, Iran

14 3 233 238 13 7 2022 13 7 2022

Background: Evidence on seroconversion profile of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients is limited. We mainly aimed to evaluate seroconversion and persistence of virus-specific antibodies in patients infected by coronavirus disease 2019 (COVID-19). Methods: This prospective study was conducted on 118 patients with COVID-19 presentations admitted to three hospitals in Iran and recovered from the disease, during April and May 2020. Presence of COVID-19 was confirmed by Polymerase Chain Reaction (PCR) testing on nasopharyngeal swabs. Serum samples were collected at different time points, including 0-5, 6-15, 16-25, 26-35, and 36-95 days of clinical symptom onset. For measurement of SARS-CoV-2-specific IgG and IgM antibody titers, Iran's Food and Drug Administration-approved SARS-CoV-2 ELISA kits were used. Results: Serologic assay revealed that 37.3% of patients (n=44) were positive for IgM at 0-5 days interval after clinical symptom onset. This rate was 60.2% (n=71) for IgG. There were increasing IgM and IgG seroconversion rates during first 25 days of clinical symptom onset, but seropositivity started to decrease thereafter, which was more evident for IgM (17.9%) than IgG (58.9%) at the 36-95 days post symptoms appearance. In other words, it was found that 83.6% of IgM-positive and 32.9% of IgG-positive patients in the first month of clinical symptom onset became seronegative in the third month of clinical symptom onset. Conclusion: The findings demonstrated that antibody responses to SARS-CoV-2 infection were developed in recovered COVID-19 patients; however, some of them were seronegative three months after onset of relevant symptoms. Furthermore, the stability of anti-SARS-CoV-2 antibodies could also correct our expectations from COVID-19 vaccination responses.