This Opinion on the impact of the post-COVID-19 condition also termed long COVID, from the Expert Panel is based on a review of the available evidence (including ongoing work from the ECDC and EMA) and any other relevant ongoing research activities, published before early 2022. There is growing evidence that SARS-CoV-2 can give rise to various post-acute consequences involving several mechanisms with some of them poorly understood.
As knowledge is permanently evolving, the Expert Panel decided to highlight some of its key and still unclear issues. The panel reviewed the existing definition on long COVID and stayed on the WHO clinical case definition.
Although the most common symptoms seem to be fatigue, shortness of breath, and cognitive dysfunction, several others, which generally have an impact on everyday functioning, have been reported. A major constraint in recognising an accurate prevalence of long COVID is the lack of surveillance in many places.
The prevalence of selfreported long COVID seems to be greatest in groups of the population that partly overlap (people aged 35 to 69 years, females, people living in more deprived areas, hospitalisation during the acute phase, immunoglobulin signature, number of symptoms in the acute phase, those working in social care, those aged 16 years or over whom were not students or retired and who were not in or looking for paid work, and those with another activitylimiting health condition or disability, smoking, vaccination status and SARS-CoV-2 variant). There is also some evidence that the prevalence of long COVID was higher amongst patients recruited in the hospital setting when compared to the community setting.
Multiple non-mutually exclusive mechanisms have been implicated in the pathogenesis of long COVID including direct effects of the acute illness resulting in organ damage and tissue injury; persistent viral material reservoirs in certain body tissues; autoimmune and molecular mimicry mechanisms; interactions with host microbiome; dysfunctional coagulation; and impaired neuronal signalling. The panel reviewed also the long COVID in children and adolescents as well as long COVID Stigma.
There are several unanswered research questions on long COVID and they have been clearly presented in a Box with 15 items. Organisational and resource requirements for healthcare systems to design and develop appropriate health services for long COVID have been discussed with a focus on: implications for the health workforce, preventing long COVID among essential workers, supporting health workers with long COVID, preventing patients from getting long COVID, models of care for patients with long COVID, health systems approach to long COVID, service delivery, health workforce, health information systems, access to essential medicines, financing, Leadership and governance.
Facing the impact of post COVID-19 condition (Long COVID) on health systems 5 Finally, the opinion composed 6 recommendations with a focus on research on long COVID and especially on: potential treatments, on health systems that need to embed research on long COVID at all levels of care (including rehabilitation), efforts to reduce transmission (including vaccination), investment on models of care that are co-ordinated in primary care and on establishment of coordinated programmes of surveillance systems.