Data from a study in the United Kingdom suggests that SARS-CoV-2 reactive T cells may be sufficient to give protection from COVID-19 and that serology alone may underestimate those at lower risk of clinical SARS-CoV-2 infection, according to a press release.
Posted on MedRxiv, the study was a collaborative effort between Oxford Immunotec Global and Public Health England (PHE). The prospective cohort study presents data generated as part of the EDSAB-HOME study, which investigated both antibody (serology) and T cell responses in a cohort of police, fire and healthcare workers.
In the study, T cell tests were conducted at enrollment in almost 3,000 participants using the company’s standardized research use only T-SPOT Discovery SARS-CoV-2 assay.
These individuals were then followed up for subsequent development of symptomatic. PCR testing confirmed SARS-CoV-2 infection. None of the participants with a high T cell response developed symptomatic SARS-CoV-2 infection in the follow-up period, whereas amongst those with low T cell responses, there were 20 confirmed infections. Further follow-up is planned, allowing for updated analyses as case numbers rise which may help yield additional insights into disease risk.
These, and additional results from the data, suggest that:
· Serology alone may underestimate the working-age population at lower risk of clinical SARS-CoV-2 infection
· Individual level risk stratification may be possible using T cell assays
· Numbers of individuals with high levels of SARS-CoV-2 responsive T cells declines with increasing age, specifically in the absence of antibodies (serology), and this may explain higher illness incidence and severity in this group
· The T-SPOT Discovery SARS-CoV-2 test detected PCR confirmed SARS-CoV-2 infections that were not positive in antibody (serology) testing
