Longer Long Covid?

One always has to take self-report data with a pinch of salt. The Office for National Statistics (ONS) carried out a study on more than 8000 people in England who had tested positive for Covid-19. It strongly suggests that many had persisting symptoms (https://www.theguardian.com/society/2020/dec/16/long-covid-alarm-as-21-report-symptoms-after-five-weeks). The subjects were from randomly-selected households and the symptoms included fever, muscle ache, diarrhoea and loss of taste and smell. The ONS study (it has some ambiguities) suggests that 21% of their sample had symptoms 5 weeks after the infection and the symptoms were still evident after 12 weeks in 10% of the sample. If these findings are true, Long Covid is much more prevalent than had been assumed. Given the limited duration of the study, it is also unclear how long Long Covid can last.