Evaluating the impact of COVID-19 or SARS-CoV-2 vaccination on TB infection testing in the context of TB elimination

<sec><title>OBJECTIVES</title>The impact of COVID-19 and SARS-CoV-2-vaccination on interferon-gamma release assay (IGRA) indeterminate results is unclear. This mini-review aims to examine whether COVID-19 or SARS-CoV-2-vaccination affects the accuracy of IGRAs by increasing the indeterminate rate.</sec><sec><title>METHODS</title>Non-systematic literature review based on a PubMed search using specific keywords, including various combinations of 'TB', 'quantiferon', 'indeterminate or negative results' and 'covid' without any time limits.</sec><sec><title>RESULTS</title>A systematic review found an overall pooled effect size (equivalent to the indeterminate results) of 0.26 (95% confidence: 0.205-0.32) for QuantiFERON TB Plus (QFT-TB) with a mean true effect size of 0.26 (95% prediction interval: 0.11-0.5), and other studies confirmed the link with disease severity. SARS-CoV-2 vaccination does not affect IGRA interpretation.</sec><sec><title>CONCLUSIONS</title>The use of IGRAs is not significantly affected by the COVID-19 pandemic or vaccinations, except in a small number of severe cases observed during the pandemic's peak. IGRAs' reliability remains consistent with their pre-pandemic performance.</sec>.