Early detection of neutralizing antibodies against SARS-CoV-2 in COVID-19 patients in Thailand

• Published in: PloS one 2021-02, Vol.16 (2), p.e0246864
• Main Authors: Putcharoen, Opass, Wacharapluesadee, Supaporn, Chia, Wan Ni, Paitoonpong, Leilani, Tan, Chee Wah, Suwanpimolkul, Gompol, Jantarabenjakul, Watsamon, Ruchisrisarod, Chanida, Wanthong, Phanni, Sophonphan, Jiratchaya, Chariyavilaskul, Pajaree, Wang, Lin-Fa, Hemachudha, Thiravat
• Format: Article
• Language: English
• Subjects: Adult; Antibodies; Antibodies, Neutralizing - analysis; Antibodies, Neutralizing - isolation & purification; Antibodies, Viral - isolation & purification; Asymptomatic infection; Biology and life sciences; Contact tracing; Coronaviruses; Cough; COVID-19; COVID-19 - diagnosis; COVID-19 - immunology; COVID-19 Nucleic Acid Testing; COVID-19 Serological Testing - methods; Editing; Electronic mail; Female; Fever; HIV; Hospitals; Human immunodeficiency virus; Humans; Humoral immunity; Immune response; Immune system; Infections; Infectious diseases; Male; Measurement; Medicine; Medicine and health sciences; Metropolitan areas; Middle Aged; Myalgia; Neutralization Tests - methods; Nose; Olfaction; Pandemics; Patients; Pediatrics; Pharmacogenomics; Pharmacokinetics; Pharmacology; Pneumonia; Polymerase chain reaction; Public health; Research and Analysis Methods; SARS-CoV-2 - physiology; Sensitivity and Specificity; Serologic Tests; Serology; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Signs and symptoms; Smell; Spike Glycoprotein, Coronavirus - chemistry; Thailand; Training; Vaccines; Viral antibodies; Viral diseases; Viral infections; Viruses; Young Adult; Zoonoses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0246864

The presence of neutralizing antibodies (NAbs) is an indicator of protective immunity for most viral infections. A newly developed surrogate viral neutralization assay (sVNT) offers the ability to detect total receptor binding domain-targeting NAbs in an isotype-independent manner, increasing the test sensitivity. Thus, specimens with low IgM/ IgG antibody levels showed strong neutralization activity in sVNT. This study aimed to measure the %inhibition of NAbs measured by sVNT in PCR-confirmed COVID-19 patients. The sensitivity of sVNT for the diagnosis of SARS-CoV-2 infection and its kinetics were determined. Ninety-seven patients with PCR-confirmed SARS-CoV-2 infection were included in this study. Majority of the patients were 21-40 years old (67%) and 63% had mild symptoms. The sensitivity of sVNT for the diagnosis of SARS-CoV-2 infection was 99% (95% confidence interval (CI) 94.4-100%) and the specificity was 100% (95% CI 98.3-100%). The negative predictive value of sVNT from the samples collected before and after 7 days of symptom onset was 99.5% (95% CI 97.4-100%) and 100% (95% CI 93.8-100%), respectively. The level of inhibition at days 8-14 were significantly higher than days 0-7 (p