What makes long Covid long: New evidence raises concern and diagnostic hope

Research finds persistent immune and clotting abnormalities, underscoring the scale of India's long Covid burden and its impact on heart and vascular health

More than five years after the first wave, Covid-19 continues to cast its shadow over India’s health landscape. A new study published in the Journal of Medical Virology (October 2025) has added renewed urgency to the need to tackle a subject clinicians have been flagging over the years: Persistent blood abnormalities in long Covid patients that may be causing chronic fatigue, cognitive problems, and cardiovascular symptoms. 

The study — led by researchers from France and South Africa — found that long Covid patients showed lasting changes in their ‘complement system’ — a group of 20 proteins