As posted about it repeatedly, there are long COVID cases, that is, post acute sequelae of SARS CoV2 infection, PASC in abbreviation, in 30 to 50 % of patients, irrespective of clinical severity. The symptoms are widely varied from ansomnia to general fatigue. The pathophysioligical process of this condition is not fully elucidated yet.
It could be a burden to the society due to the necessity of social security for them. It could bother them to return to social activities. PASC should be a big problem in every country from now on.
The following report says PASC could be due to long lasting immunological activation. It could be regarded as smoldering cytokine storm. With PASC, the cytokines were measured significantly high and paralleled to the symptom score. IL6 elevated higher as time went on. It seems to be comparable to the cytokine storm which makes COVID19 serious and often fatal in the acute phase even if the severity and progression to multiple organ failure are not observed in PASC.
VOC variants are more infectious than the original strain. Young people are prone to be infected by those strains. It won't be like flu but could leave this troublesome sequelae to acutely infected people. That is another reason that we should take vaccine for this viral infection.