An analysis of brain scans of participants in the UK Biobank has shown there are significant differences between the condition of the brain before and after mild COVID-19 infection. These included a reduction in overall brain size, reduction in grey matter thickness in the orbitofrontal cortex and hippocampal gyrus, and changes in markers of tissue damage in regions functionally connected to the primary olfactory cortex. Infected participants also showed, on average, a larger cognitive decline than participants who had not contracted COVID-19.

The world’s largest genomics study in patients with life-threatening COVID-19 infections has uncovered 16 new genetic variants associated with severe disease and drawn up a roadmap for research into new therapies and diagnostics. The research involved comparing the complete genome sequences of 7,491 patients admitted to 224 intensive care units in the U.K. against those of 48,400 participants in Genomics England’s 100,000 Genomes project, and of a further 1,630 people who had mild COVID-19. While some of the gene variants found in the Genomicc study affect the function of a protein, others influence the amount of the protein that is expressed. An example is mucin-1, where overexpression led to worse outcomes.