Fig. 3

Regression analysis and agreement of the HIV(SARS–CoV–2) PVNA and VSV(SARS–CoV–2) PVNA with a live virus SARS–CoV–2 neutralisation assay in HIV-infected participants. Sera from HIV–infected participants were assessed for neutralising activity against the Ancestral B.1, or variants Beta, Delta, and Omicron BA.1. (A) Linear regression analysis between percent neutralisation generated by the HIV(SARS–CoV–2)–based assay and the live virus SARS–CoV–2 assay for each SARS–CoV–2 lineage. Red dotted lines show the 90% cut–off for both assays. Blue line displays the best fit linear regression line with the grey shaded area showing the 95% confidence interval. Text shows the equation of the regression line in the form y = c + mx where m is the gradient. (B) Bland–Altman plot showing the agreement between the HIV(SARS–CoV–2)–based assay and the live virus SARS–CoV–2 assay. The black line is the mean difference between the tests for paired samples. The red dotted lines are the 95% limit of agreement. (C) Linear regression analysis between percent neutralisation derived using the VSV(SARS–CoV–2)–based assay and the live virus SARS–CoV–2 assays. Red dotted lines show the 90% cut–off for both assays. Blue line displays the best fit correlation with the grey shaded area showing the 95% confidence interval. Blue line displays the best fit linear regression line with the grey shaded area showing the 95% confidence interval. Text shows the equation of the regression line in the form y = c + mx where m is the gradient. (D) Bland–Altman plot showing the agreement between the VSV(SARS–CoV–2)–based assay and the live virus SARS–CoV–2 assay. The black line is the mean difference between the tests for paired samples. The red dotted lines are the 95% limit of agreement.