Scientists continue to gain a better understanding of the many facets of COVID-19, such as how to:
· Enhance the vaccine efficacy
· Prevent COVID-19 transmission
· Better manage infected individuals
· Diagnose infections promptly with the highest degree of sensitivity and specificity
Of all of these obstacles, one of the first challenges for scientists to overcome was devising effective diagnostics for SARS-CoV-2, which they achieved in record time. However, as newer information emerges daily, it seems like we still do not have a complete picture of all aspects of COVID-19.
In an eloquent article from Nature, a group of scientists from the United Kingdom utilized an intensively monitored cohort of healthcare workers with potential exposure during the first UK pandemic wave. Comparing those with or without PCR and/or antibody evidence of SARS-CoV-2 infection, this study demonstrated that not all with potential exposure to SARS-CoV-2 developed PCR or antibody positivity, potentially due to clearing the sub-clinical infection before seroconversion – the phenomenon they coined as ‘Abortive, Seronegative SARS-CoV-2 Infection.’
In such instances where PCR and the most sensitive antibody tests remained repeatedly negative, T-cell assays might be able to detect those subclinical infections since these individuals would exhibit pre-existing memory T-cells with cross-reactive potential.