People with mild Covid-19 who do not suffer any other traditional "long Covid" symptoms can still exhibit deteriorated attention and memory six to nine months after infection, a study by Britain's Oxford University has found.

Cognitive issues impacting concentration levels, along with forgetfulness and fatigue, are features of long Covid - a condition that afflicts some after an initial bout of infection - but it has not been established how widespread issues with attention span might be following Covid-19 infection.

In the study, participants who had tested positive for Covid-19 previously but...