Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study

Asma Al Balushi; Zainab Abdul Hameed; Hasina Al Bahri; Zaina Al Maskari; Ahlam Al Balushi; Iman Al Balushi; Sachin Jose; Adil Al Wahaibi; Amina Al-Jardani; Samira Al-Mahruqi; Mohammed Hamed Nasr; Emily Adams; Tom E. Fletcher; Iman Nasr

doi:10.1016/j.ijregi.2025.100736

Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study

Asma Al Balushi, Zainab Abdul Hameed, Hasina Al Bahri, Zaina Al Maskari, Ahlam Al Balushi, Iman Al Balushi, Sachin Jose, Adil Al Wahaibi, Amina Al-Jardani, Samira Al-Mahruqi, Mohammed Hamed Nasr, Emily Adams, Tom E. Fletcher, Iman Nasr

Research output: Contribution to journal › Article › peer-review

Abstract

Objectives: The durability of SARS-CoV-2 antibody response varies with disease severity [1]. Comparative data across diverse clinical settings in the Gulf region are limited. This study assessed the persistence of SARS-CoV-2 immunoglobulin G (IgG) antibodies over 6 months among hospitalized patients, outpatients, and healthcare workers (HCWs).

Methods: In this prospective cohort study, 356 confirmed COVID-19 cases (123 inpatients, 113 outpatients, and 120 HCWs) were enrolled. Serum IgG titers were measured using enzyme-linked immunosorbent assay (ELISA) at baseline (≤14 days post-symptom onset), 4-6 weeks, 3 months, and 6 months post-infection. Longitudinal antibody dynamics were analyzed using a linear mixed-effect model adjusting for patient group, age, comorbidities, and symptoms.

Results: Inpatients were older, male, and had more comorbidities, including obesity 54.5% (67 of 123), diabetes mellitus 39% (48 of 123), and hypertension 39.8% (49 of 123), compared with outpatients and HCWs. Peak antibody titers were reached at 4-6 weeks, with gradual decline over the 6-month period after initial infection across all groups (P <0.001). Inpatients demonstrated significantly higher IgG titers at all time points (P <0.001).

Conclusions: Severe COVID-19 infection, older age, and comorbidities were linked to stronger, more durable IgG responses. These findings provide essential baseline data on post–COVID-19 immunity in the Gulf region during early pandemic.

Original language	English
Article number	100736
Journal	IJID Regions
Volume	17
DOIs	https://doi.org/10.1016/j.ijregi.2025.100736
Publication status	Published - 24 Sept 2025

Keywords

Antibody response
COVID-19
ELISA
Linear mixed effects model
SARS-CoV-2
Serology

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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Al Balushi, A., Abdul Hameed, Z., Al Bahri, H., Al Maskari, Z., Al Balushi, A., Al Balushi, I., Jose, S., Al Wahaibi, A., Al-Jardani, A., Al-Mahruqi, S., Nasr, M. H., Adams, E., Fletcher, T. E., & Nasr, I. (2025). Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study. IJID Regions, 17, Article 100736. https://doi.org/10.1016/j.ijregi.2025.100736

@article{d99fca6be0b440558ab895597a842914,

title = "Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study",

abstract = "Objectives: The durability of SARS-CoV-2 antibody response varies with disease severity [1]. Comparative data across diverse clinical settings in the Gulf region are limited. This study assessed the persistence of SARS-CoV-2 immunoglobulin G (IgG) antibodies over 6 months among hospitalized patients, outpatients, and healthcare workers (HCWs). Methods: In this prospective cohort study, 356 confirmed COVID-19 cases (123 inpatients, 113 outpatients, and 120 HCWs) were enrolled. Serum IgG titers were measured using enzyme-linked immunosorbent assay (ELISA) at baseline (≤14 days post-symptom onset), 4-6 weeks, 3 months, and 6 months post-infection. Longitudinal antibody dynamics were analyzed using a linear mixed-effect model adjusting for patient group, age, comorbidities, and symptoms. Results: Inpatients were older, male, and had more comorbidities, including obesity 54.5\% (67 of 123), diabetes mellitus 39\% (48 of 123), and hypertension 39.8\% (49 of 123), compared with outpatients and HCWs. Peak antibody titers were reached at 4-6 weeks, with gradual decline over the 6-month period after initial infection across all groups (P <0.001). Inpatients demonstrated significantly higher IgG titers at all time points (P <0.001). Conclusions: Severe COVID-19 infection, older age, and comorbidities were linked to stronger, more durable IgG responses. These findings provide essential baseline data on post–COVID-19 immunity in the Gulf region during early pandemic.",

keywords = "Antibody response, COVID-19, ELISA, Linear mixed effects model, SARS-CoV-2, Serology",

author = "\{Al Balushi\}, Asma and \{Abdul Hameed\}, Zainab and \{Al Bahri\}, Hasina and \{Al Maskari\}, Zaina and \{Al Balushi\}, Ahlam and \{Al Balushi\}, Iman and Sachin Jose and \{Al Wahaibi\}, Adil and Amina Al-Jardani and Samira Al-Mahruqi and Nasr, \{Mohammed Hamed\} and Emily Adams and Fletcher, \{Tom E.\} and Iman Nasr",

note = "Publisher Copyright: {\textcopyright} 2025 The Authors",

year = "2025",

month = sep,

day = "24",

doi = "10.1016/j.ijregi.2025.100736",

language = "English",

volume = "17",

journal = "IJID Regions",

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Al Balushi, A, Abdul Hameed, Z, Al Bahri, H, Al Maskari, Z, Al Balushi, A, Al Balushi, I, Jose, S, Al Wahaibi, A, Al-Jardani, A, Al-Mahruqi, S, Nasr, MH, Adams, E, Fletcher, TE & Nasr, I 2025, 'Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study', IJID Regions, vol. 17, 100736. https://doi.org/10.1016/j.ijregi.2025.100736

TY - JOUR

T1 - Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study

AU - Al Balushi, Asma

AU - Abdul Hameed, Zainab

AU - Al Bahri, Hasina

AU - Al Maskari, Zaina

AU - Al Balushi, Ahlam

AU - Al Balushi, Iman

AU - Jose, Sachin

AU - Al Wahaibi, Adil

AU - Al-Jardani, Amina

AU - Al-Mahruqi, Samira

AU - Nasr, Mohammed Hamed

AU - Adams, Emily

AU - Fletcher, Tom E.

AU - Nasr, Iman

PY - 2025/9/24

Y1 - 2025/9/24

N2 - Objectives: The durability of SARS-CoV-2 antibody response varies with disease severity [1]. Comparative data across diverse clinical settings in the Gulf region are limited. This study assessed the persistence of SARS-CoV-2 immunoglobulin G (IgG) antibodies over 6 months among hospitalized patients, outpatients, and healthcare workers (HCWs). Methods: In this prospective cohort study, 356 confirmed COVID-19 cases (123 inpatients, 113 outpatients, and 120 HCWs) were enrolled. Serum IgG titers were measured using enzyme-linked immunosorbent assay (ELISA) at baseline (≤14 days post-symptom onset), 4-6 weeks, 3 months, and 6 months post-infection. Longitudinal antibody dynamics were analyzed using a linear mixed-effect model adjusting for patient group, age, comorbidities, and symptoms. Results: Inpatients were older, male, and had more comorbidities, including obesity 54.5% (67 of 123), diabetes mellitus 39% (48 of 123), and hypertension 39.8% (49 of 123), compared with outpatients and HCWs. Peak antibody titers were reached at 4-6 weeks, with gradual decline over the 6-month period after initial infection across all groups (P <0.001). Inpatients demonstrated significantly higher IgG titers at all time points (P <0.001). Conclusions: Severe COVID-19 infection, older age, and comorbidities were linked to stronger, more durable IgG responses. These findings provide essential baseline data on post–COVID-19 immunity in the Gulf region during early pandemic.

AB - Objectives: The durability of SARS-CoV-2 antibody response varies with disease severity [1]. Comparative data across diverse clinical settings in the Gulf region are limited. This study assessed the persistence of SARS-CoV-2 immunoglobulin G (IgG) antibodies over 6 months among hospitalized patients, outpatients, and healthcare workers (HCWs). Methods: In this prospective cohort study, 356 confirmed COVID-19 cases (123 inpatients, 113 outpatients, and 120 HCWs) were enrolled. Serum IgG titers were measured using enzyme-linked immunosorbent assay (ELISA) at baseline (≤14 days post-symptom onset), 4-6 weeks, 3 months, and 6 months post-infection. Longitudinal antibody dynamics were analyzed using a linear mixed-effect model adjusting for patient group, age, comorbidities, and symptoms. Results: Inpatients were older, male, and had more comorbidities, including obesity 54.5% (67 of 123), diabetes mellitus 39% (48 of 123), and hypertension 39.8% (49 of 123), compared with outpatients and HCWs. Peak antibody titers were reached at 4-6 weeks, with gradual decline over the 6-month period after initial infection across all groups (P <0.001). Inpatients demonstrated significantly higher IgG titers at all time points (P <0.001). Conclusions: Severe COVID-19 infection, older age, and comorbidities were linked to stronger, more durable IgG responses. These findings provide essential baseline data on post–COVID-19 immunity in the Gulf region during early pandemic.

KW - Antibody response

KW - COVID-19

KW - ELISA

KW - Linear mixed effects model

KW - SARS-CoV-2

KW - Serology

U2 - 10.1016/j.ijregi.2025.100736

DO - 10.1016/j.ijregi.2025.100736

M3 - Article

AN - SCOPUS:105016815031

SN - 2772-7076

VL - 17

JO - IJID Regions

JF - IJID Regions

M1 - 100736

ER -

Persistence of SARS-CoV-2 Antibody Response across Diverse Clinical Settings in Oman: Insights from a Prospective ELISA-based Study

Abstract

Keywords

UN SDGs

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