An analysis of 54 studies involving 1.2 million individuals from 22 countries who had Covid-19 has revealed that 6.2 percent of them experienced at least one of the three long Covid-19 symptoms -- persistent fatigue with bodily pain or mood swings, cognitive problems, or ongoing respiratory problems -- three months after acute infection onset.

Among individuals with long Covid-19 symptoms three months after symptomatic SARS-CoV-2 infection, an estimated 15.1 per cent continued to experience symptoms at 12 months.