JMIR Publications

ABSTRACT

Background:

This paper illustrates the development of a simple online application, which demonstrates the relationship between serum anti-SARS-CoV-2 S1/RBD IgG and anti-SARS-CoV-2 neutralizing antibody IC50 (nAb) titers in a US adult vaccinated population and compares them to prior data on nAb titers at different time points after vaccination.

Objective:

The objective of this web-application is to create an easily accessible calculator that uses the results of commercially available anti-SARS-CoV-2 serum IgG to approximate the underlying ability to neutralize SARS-CoV-2.

Methods:

Our web-based application leverages two previously published datasets. One dataset demonstrated a robust correlation between nAb and serum IgG. The other dataset measured nAb titers at specific time periods over a year-long interval following an mRNA vaccination primary series and booster vaccine dose. Clinical factors that were found to be statistically significant on a forwards linear regression model examining the prediction of nAb from serum IgG were incorporated in the application tool.

Results:

By combining the datasets described above, we have developed a publicly available web-based application that allows users to enter a serum IgG value and determine their estimated nAb titer. The application contextualizes the estimated nAb titer with the theoretical distance from the corresponding vaccine mediated antibody protection. Using the clinical variables found to have a significant impact in how IgG predicts nAb, this application allows for a patient-centered estimated neutralizing antibody prediction.

Conclusions:

This application offers an example of how we might bring the advances made in scientific research on post-SARS-CoV-2 vaccination protective antibodies into the clinical sphere with practical tools.