This is a good overview of long covid, and what we are trying to avoid.
From an extensive body of mechanistic research in people affected by Long Covid, there appear to be multiple potential pathogenic pathways, including persistence of the virus or its components in tissue reservoirs; autoimmune or an unchecked, dysregulated immune response; mitochondrial dysfunction; vascular (endothelial) and/or neuronal inflammation; and microbiome dysbiosis (2). In people with severe COVID-19, systemic acute infection can arise in which SARS-CoV-2 replicates in pulmonary and extrapulmonary tissue, and its genomic RNA may persist for months in multiple sites, including the brain and coronary arteries (3). To what extent this happens in milder cases and whether this contributes mechanistically to Long Covid is not yet clear. SARS-CoV-2 may also reactivate dormant viruses, including Epstein-Barr virus and varicella zoster virus, as well as lead to gut-brain and neuroendocrine dysfunction, mitochondrial dysfunction, and impaired coagulation (4, 5) (see the figure).
Preventing infections and reinfections is the best way to prevent Long Covid and should remain the foundation of public health policy. A greater commitment to nonpharmaceutical interventions, which include masking, especially in high-risk settings, and improved air quality through filtration and ventilation, are requisite. Updating building codes to require mitigation against airborne pathogens and ensure safer indoor air should be treated with the same seriousness afforded to mitigation of risks from earthquakes and other natural hazards. Reducing the risk of serious outcomes after COVID-19 and some prevention of Long Covid can be attained with vaccination of a wider spectrum of the population. Given the dwindling appetite for COVID-19 boosters, strategies to improve uptake (e.g., pairing it with the annual influenza vaccine) may be effective. Development of more durable, variant-proof vaccines that are not vulnerable to evasion by the ever-mutating virus needs to be accelerated (12). Nasally or orally administered vaccines that induce strong mucosal immunity to block infection and transmission should be pursued, and there are preliminary supportive data from clinical trials (10). It is also necessary to broaden the pipeline of SARS-CoV-2 antivirals, especially because of rising resistance (13).