Evaluation of Simple Lateral Flow Immunoassays for Detection of SARS-CoV-2 Neutralizing Antibodies

Abstract

Immunization for the generation of protective antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged to be highly effective in preventing hospital admission, need for intensive care treatment and high mortality in the current SARS-CoV-2 pandemic. Lateral flow immune assays (LFIAs) offer a simple and competitive option to monitor antibody production after vaccination. Here, we compared the diagnostic performance of three different lateral flow assays in detecting nucleocapsid protein (NP), S1 subunit (S1) and receptor binding domain (pseudo)-neutralizing antibodies (nRBD) in sera of 107 health care workers prior (V1), two weeks (V2) after first vaccination with BNT162b2 as well as three weeks (V3) and eight months later (V4). In sera at V1, overall specificity was >99%. At V3, LFIAs showed sensitivities between 98.1 and 100%. The comparison of S1 and nRBD LFIA with S1 ELISA and a focus reduction neutralization assay (FRNT) revealed high concordance at V3. Thus, the use of lateral flow immunoassays appears to have reasonable application in the short-term follow-up after vaccination for SARS-CoV-2.

Research progress in methods for detecting neutralizing antibodies against SARS-CoV-2

“…To understand the ability of NAbs to block the binding of viruses to their receptors, many methods have been established to measure these antibodies, such as the plaque reduction neutralization test (PRNT), which is considered the gold standard; the highly sensitive pseudovirus neutralization assay; the simple enzyme-linked immunosorbent assay; and the lateral flow immunoassay, which can be used outside of the laboratory [ [35] , [36] , [37] , [38] ]. The research progress on technologies for the detection of NAbs against SARS-CoV-2 were reviewed in this paper by consulting the literature, with an aim to identify research directions and references for researchers and medical staff.…”

An update on lateral flow immunoassay for the rapid detection of SARS-CoV-2 antibodies

“…An effort has been done to establish a putative role for LFIA in determining the longevity of vaccine-induced protection. One group followed-up the response to BNT162b2 by three different LFIAs detecting N protein, S1 subunit and RBD NAbs in the sera of 107 health care workers up to 8 months from vaccination [129] . After three weeks, the RBD-based LFIA showed a sensitivity between 98% and 100%, but after 8 months this sensitivity significantly dropped compared to laboratory quantitative tests.…”

Challenges in the Detection of SARS-CoV-2: Evolution of the Lateral Flow Immunoassay as a Valuable Tool for Viral Diagnosis

“…In 2021, the need for LFIAs antibody tests to detect with high sensitivity and/or quantitative mode neutralizing antibodies in individuals immunized or recovered from natural COVID-19 illness resurfaced [ 83 , 84 , 85 ]. The novel vaccines manufactured against SARS-CoV-2 make it necessary to assess the efficiency of immunization to produce neutralizing antibodies against SARS-CoV-2 and how long they last in the vaccinated individual [ 84 , 86 ]. The speed and affordability of the LFIA test allow timely detection of individuals who show a short or absent humoral immune response.…”

“…Even it is possible that N-LFIA could detect SARS-CoV-2 in asymptomatic personnel at high risk. Nickel and colleagues (2022) carried out the N-LFIA serological test on at-risk healthcare workers and detected antibodies to the N viral protein with a sensitivity of >99%, indicating prior infection [ 86 ]. The early identification of individuals with antibodies against viral protein N could be considered a biomarker of the previous infection.…”