COVID-19 Neutralizing Antibodies Predict Disease Severity and Survival

COVID-19 exhibits variable symptom severity ranging from asymptomatic to life-threatening, yet the relationship between severity and the humoral immune response is poorly understood. We examined antibody responses in 113 COVID-19 patients and found that severe cases resulting in intubation or death exhibited increased inflammatory markers, lymphopenia, and high anti-RBD antibody levels. While anti-RBD IgG levels generally correlated with neutralization titer, quantitation of neutralization potency revealed that high potency was a predictor of survival. In addition to neutralization of wild-type SARS-CoV-2, patient sera were also able to neutralize the recently emerged SARS-CoV-2 mutant D614G, suggesting protection from reinfection by this strain. However, SARS-CoV-2 sera was unable to cross-neutralize a highly-homologous pre-emergent bat coronavirus, WIV1-CoV, that has not yet crossed the species barrier. These results highlight the importance of neutralizing humoral immunity on disease progression and the need to develop broadly protective interventions to prevent future coronavirus pandemics. Funding: K.L.C. is supported by Ruth L. Kirschstein National Research Service Award (NRSA) Individual Postdoctoral Fellowship 1F32AI143480. T.M.C. and B.M.H. were supported by award Number T32GM007753 from the National Institute of General Medical Sciences. J.F. was supported by T32AI007245. A.G.S. was supported by NIH R01 AI146779 and a Massachusetts Consortium on Pathogenesis Readiness (MassCPR) grant. J.A.B. has received research support from Zeus Scientific, bioMerieux, Immunetics, Alere, DiaSorin, the Bay Area Lyme Foundation (BALF), and the National Institute of Allergy and Infectious Diseases (NIAID; Award 1R21AI119457-01) for unrelated projects. J.A.B. has served as a paid consultant to T2 Biosystems, DiaSorin and Roche Diagnostics. A.J.I. is supported by the Lambertus Family Foundation. A.B.B. is supported by the National Institutes for Drug Abuse (NIDA) Avenir New Innovator Award DP2DA040254, the MGH Transformative Scholars Program as well as funding from the Charles H. Hood Foundation. This independent research was supported by the Gilead Sciences Research Scholars Program in HIV. Ethical Approval: Use of patient samples for the development and validation of SARS-CoV-2 diagnostic tests was approved by Partners Institutional Review Board (protocol 2020P000895).