Prediction models for neutralization activity against emerging SARS-CoV-2 variants: A cross-sectional study

Abstract

ObjectiveDespite extensive vaccination campaigns to combat the coronavirus disease (COVID-19) pandemic, variants of concern, particularly the Omicron variant (B.1.1.529 or BA.1), may escape the antibodies elicited by vaccination against SARS-CoV-2. Therefore, this study aimed to evaluate 50% neutralizing activity (NT50) against SARS-CoV-2 D614G, Delta, Omicron BA.1, and Omicron BA.2 and to develop prediction models to predict the risk of infection in a general population in Japan.MethodsWe used a random 10% of samples from 1,277 participants in a population-based cross-sectional survey conducted in January and February 2022 in Yokohama City, the most populous municipality in Japan. We measured NT50 against D614G as a reference and three variants (Delta, Omicron BA.1, and BA.2) and immunoglobulin G against SARS-CoV-2 spike protein (SP-IgG).ResultsAmong 123 participants aged 20–74, 93% had received two doses of SARS-CoV-2 vaccine. The geometric means (95% confidence intervals) of NT50 were 65.5 (51.8–82.8) for D614G, 34.3 (27.1–43.4) for Delta, 14.9 (12.2–18.0) for Omicron BA.1, and 12.9 (11.3–14.7) for Omicron BA.2. The prediction model with SP-IgG titers for Omicron BA.1 performed better than the model for Omicron BA.2 (bias-corrected R2 with bootstrapping: 0.721 vs. 0.588). The models also performed better for BA.1 than for BA.2 (R2 = 0.850 vs. 0.150) in a validation study with 20 independent samples.ConclusionIn a general Japanese population with 93% of the population vaccinated with two doses of SARS-CoV-2 vaccine, neutralizing activity against Omicron BA.1 and BA.2 were substantially lower than those against D614G or the Delta variant. The prediction models for Omicron BA.1 and BA.2 showed moderate predictive ability and the model for BA.1 performed well in validation data.

Humoral response against spike protein enhanced by fifth and sixth COVID-19 mRNA vaccine in the uninfected and infected subjects

“…COVID-infected individuals were also found to have twice as much S-IgG compared to uninfected individuals who had been vaccinated in the same number of doses as we previously reported in standard population. 11 This is consistent with previous reports that vaccination reduces the risk of reinfection in infected individuals and is supported by the antibody titers. 12 The strategy of preventing infection by humoral immunity in COVID-19 is facing challenges due to the emergence of mutant strains.…”

A SARS-CoV-2: Companion Animal Transmission and Variants Classification

“…The Delta variant has demonstrated a decrease in the effectiveness of COVID-19 vaccines (96% for Oxford-AstraZeneca, 92% for Pfizer-BioNtech) against SARS-CoV-2 infection and hospitalization patients compared to previous variants [ 150 ]. Likewise, the Delta variant has a reduction in neutralization immunity by convalescent sera and post-vaccination sera [ 115 , 124 , 151 , 152 ].…”

“…The Delta variant has demonstrated a decrease in the effectiveness of COVID-19 vaccines (96% for Oxford-AstraZeneca, 92% for Pfizer-BioNtech) against SARS-CoV-2 infection and hospitalization patients compared to previous variants [150]. Likewise, the Delta variant has a reduction in neutralization immunity by convalescent sera and post-vaccination sera [115,124,151,152] The most recently designated VOC, Omicron, was first detected in Botswana and South Africa in November 2021 and has spread to most countries [86]. The WHO has warned the global public about the enhanced immune escape potential, higher transmissibility, and the global spread of Omicron, particularly in countries with low vaccination rates [86,130].…”