Evaluation of Eight Lateral Flow Tests For The Detection Of Anti-SARS-CoV-2 Antibodies In A Vaccinated Population

Abstract With the distribution of COVID-19 vaccinations across the globe and the limited access in many countries, quick determination of an individual’s antibody status could be beneficial in allocating limited vaccine doses in low- and middle-income countries (LMIC). Antibody lateral flow tests (LFTs) have potential to address this need as a quick, point of care test, they also have a use case for identifying sero-negative individuals for novel therapeutics, and for epidemiology. Here we present a proof-of-concept evaluation of eight LFT brands using sera from 95 vaccinated individuals to determine sensitivity for detecting vaccination generated antibodies. All 95 (100%) participants tested positive for anti-spike antibodies by the chemiluminescent microparticle immunoassay (CMIA) reference standard post-dose two of their SARS-CoV-2 vaccine: BNT162b2 (Pfizer/BioNTech, n=60), AZD1222 (AstraZeneca, n=31), mRNA-1273 (Moderna, n=2) and Undeclared Vaccine Brand (n=2). Sensitivity increased from dose one to dose two in six out of eight LFTs with three tests achieving 100% sensitivity at dose two in detecting anti-spike antibodies. These tests are quick, low-cost point-of-care tools that can be used without prior training to establish antibody status and may prove valuable for allocating limited vaccine doses in LMICs to ensure those in at risk groups access the protection they need. Further investigation into their performance in vaccinated peoples is required before more widespread utilisation is considered.