At least 5–10% of subjects surviving COVID-19 develop the post-COVID-19 condition (PCC) or “Long COVID”. The clinical presentation of PCC is heterogeneous, its pathogenesis is being deciphered, and objective, validated biomarkers are lacking. It is unknown if PCC is a single entity or a heterogeneous syndrome with overlapping pathophysiological basis. The large US RECOVER study identified four clusters of subjects with PCC according to their presenting symptoms. However, the long-term clinical implications of PCC remain unknown. We conducted a 2-year prospective cohort study of subjects surviving COVID-19, including individuals fulfilling the WHO PCC definition and subjects with full clinical recovery. We systematically collected post-COVID-19 symptoms using prespecified questionnaires and performed additional diagnostic imaging tests when needed. Factors associated with PCC were identified and modelled using logistic regression. Unsupervised clustering analysis was used to group subjects with PCC according to their presenting symptoms. Factors associated with PCC recovery were modelled using a direct acyclic graph approach. The study included 548 individuals, 341 with PCC, followed for a median of 23 months (IQR 16.5–23.5), and 207 subjects fully recovered. In the model with the best fit, subjects who were male and had tertiary studies were less likely to develop PCC, whereas a history of headache, or presence of tachycardia, fatigue, neurocognitive and neurosensitive complaints and dyspnea at COVID-19 diagnosis predicted the development of PCC. The cluster analysis revealed the presence of three symptom clusters with an additive number of symptoms. Only 26 subjects (7.6%) recovered from PCC during follow-up; almost all of them (n = 24) belonged to the less symptomatic cluster A, dominated mainly by fatigue. Recovery from PCC was more likely in subjects who were male, required ICU admission, or had cardiovascular comorbidities, hyporexia and/or smell/taste alterations during acute COVID-19. Subjects presenting with muscle pain, impaired attention, dyspnea, or tachycardia, conversely, were less likely to recover from PCC. Preexisting medical and socioeconomic factors, as well as acute COVID-19 symptoms, are associated with the development of and recovery from the PCC. Recovery is extremely rare during the first 2 years, posing a major challenge to healthcare systems. Fundació Lluita contra les Infeccions.

The post-COVID-19 condition (PCC) is a disabling syndrome affecting at least 5%-10% of subjects who survive COVID-19. SARS-CoV-2 mediated vagus nerve dysfunction could explain some PCC symptoms, such as dysphonia, dysphagia, dyspnea, dizziness, tachycardia, orthostatic hypotension, gastrointestinal disturbances, or neurocognitive complaints. We performed a cross-sectional pilot study in subjects with PCC with symptoms suggesting vagus nerve dysfunction (n = 30) and compared them with subjects fully recovered from acute COVID-19 (n = 14) and with individuals never infected (n = 16). We evaluated the structure and function of the vagus nerve and respiratory muscles. Participants were mostly women (24 of 30, 80%), and the median age was 44 years (interquartile range [IQR] 35-51 years). Their most prevalent symptoms were cognitive dysfunction 25 of 30 (83%), dyspnea 24 of 30 (80%), and tachycardia 24 of 30 (80%). Compared with COVID-19-recovered and uninfected controls, respectively, subjects with PCC were more likely to show thickening and hyperechogenic vagus nerve in neck ultrasounds (cross-sectional area [CSA] [mean ± standard deviation]: 2.4 ± 0.97mm2 vs. 2 ± 0.52mm2 vs. 1.9 ± 0.73 mm2; p 0.08), reduced esophageal-gastric-intestinal peristalsis (34% vs. 0% vs. 21%; p 0.02), gastroesophageal reflux (34% vs. 19% vs. 7%; p 0.13), and hiatal hernia (25% vs. 0% vs. 7%; p 0.05). Subjects with PCC showed flattening hemidiaphragms (47% vs. 6% vs. 14%; p 0.007), and reductions in maximum inspiratory pressure (62% vs. 6% vs. 17%; p ≤ 0.001), indicating respiratory muscle weakness. The latter findings suggest additional involvement of the phrenic nerve. Vagus and phrenic nerve dysfunction contribute to the complex and multifactorial pathophysiology of PCC.

The post-COVID-19 condition (PCC) is a highly debilitating and persistent postinfectious syndrome that affects millions of people worldwide and has no effective treatment. Therapeutic plasma exchange (TPE) has the potential to improve the PCC by clearing the peripheral soluble pro-inflammatory immune milieu derived from acute or persistent SARS-CoV-2 infection. In a phase II, double-blind, placebo-controlled, randomized trial, fifty subjects with PCC were randomly assigned (1:1) to receive six sessions of either TPE or a sham plasma exchange and were followed for 90 days (ClinicalTrials.gov registration: NCT05445674). The primary endpoint was safety; secondary endpoints included functional status, symptomology, quality of life, neurocognitive symptoms, and peripheral biochemistry, hematology, coagulation and inflammation parameters. Both study arms had a similarly favorable safety profile. There were no diferences between groups in any of the efficacy parameters evaluated. Whereas TPE is safe, it did not lead to any discernible improvement of the PCC in this clinical trial.

Post-COVID-19 condition (PCC) affects millions of people, and is an essential component of the long-term impact of COVID-19 during the post-pandemic era. Yet, consensus on clinical case definition and core components of PCC remains lacking, affecting our ability to inform research and evidence-based management. Our study aims 1) to identify the most specific symptoms for PCC, and identify clinical subtypes; 2) to evaluate both virus- and host-related determinants of PCC, and 3) assess the impact of PCC on physical and mental health. We studied participants from UK Biobank who completed a health and wellbeing survey between June and September 2022. Participants reported the current conditions of the presence, duration, and functional limitations of 45 symptoms, using an online questionnaire designed specifically for COVID-19 research. SARS-CoV-2 infection status and disease history were obtained through linkage to surveillance data and electronic medical records, respectively. Participants reporting symptoms within 30 days after infection (acute phase) were excluded. The most specific PCC symptoms were defined using two criteria: statistical significance (P < 0.05 after Bonferroni correction) and clinical relevance (absolute risk increase > 5%). Propensity score weighting was used to control for confounding. Subtypes of PCC were then defined based on the specific symptoms among the COVID-19 infected individuals. A multivariable regression was used to study pathogen- and host-related risk factors for PCC, and its impact on 13 physical and 4 mental health patient-reported functional outcomes. 172,303 participants (mean age 68.9, 57.4% female) were included in the analysis, of whom 43,395 had PCR-confirmed COVID-19. We identified 10 most specific symptoms and classified four PCC subtypes: ENT subtype (30.1%), characterized by alterations in smell, taste, and hearing loss; cardiopulmonary subtype (10.4%), characterized by shortness of breath, postural tachycardia, chest tightness, and chest pressure; neurological subtype (23.5%), characterized by brain fog and difficulty speaking; and general fatigue subtype (38.0%), characterized by mild fatigue. A higher PCC risk was observed for patients with Wild-type variant, multiple infections, and severe acute COVID-19 illness, consistently across the four PCC subtypes. In addition, a range of factors, including socioeconomic deprivation, higher BMI, unhealthy lifestyle, and multiple chronic health conditions, were associated with increased PCC risk, except for age and sex. Conversely, vaccination was associated with a largely reduced PCC risk, particularly for the cardiopulmonary subtypes. Individuals with PCC experienced a much worse physical and mental health. Specifically, the cardiopulmonary subtype had the most pronounced adverse impact on function impairments, followed by neurological, mild fatigue, and ENT subtype. The most affected functions included the ability to concentrate, participate in day-to-day work, and emotional vulnerability to health problems. PCC can be categorized into four distinct subtypes based on ten core symptoms. These subtypes appeared to share a majority of pathogen and host-related risk factors, but their impact on health varied markedly by subtype. Our findings could help refine current guidelines for precise PCC diagnosis and progression, enhance the identification of PCC subgroups for targeted research, and inform evidence-based policy making to tackle this new and debilitating condition. NIHR Senior Research Fellowship (grant SRF-2018-11-ST2-004).

A 42-year-old woman, presented with fever, anosmia, and a positive polymerase chain reaction for severe acute respiratory syndrome coronavirus 2.