How methodological pitfalls have created widespread misunderstanding about long COVID

Mechanisms of long COVID and the path toward therapeutics

Long COVID, a type of post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC) defined by medically unexplained symptoms following infection with SARS-CoV-2, is a newly recognized infection-associated chronic condition that causes disability in some people. Substantial progress has been made in defining its epidemiology, biology, and pathophysiology. However, there is no cure for the tens of millions of people believed to be experiencing long COVID, and industry engagement in developing therapeutics has been limited. Here, we review the current state of knowledge regarding the biology and pathophysiology of long COVID, focusing on how the proposed mechanisms explain the physiology of the syndrome and how they provide a rationale for the implementation of a broad experimental medicine and clinical trials agenda. Progress toward preventing and curing long COVID and other infection-associated chronic conditions will require deep and sustained investment by funders and industry.

Zero-covid advocacy during the COVID-19 pandemic: a case study of views on Twitter/X

During the COVID-19 pandemic, many advocacy groups and individuals criticized governments on social media for doing either too much or too little to mitigate the pandemic. In this article, we review advocacy for COVID-19 elimination or "zero-covid" on the social media platform X (Twitter). We present a thematic analysis of tweets by 20 influential co-signatories of the World Health Network letter on ten themes, covering six topics of science and mitigation (zero-covid, epidemiological data on variants, long-term post-acute sequelae (Long COVID), vaccines, schools and children, views on monkeypox/Mpox) and four advocacy methods (personal advice and promoting remedies, use of anecdotes, criticism of other scientists, and of authorities). The advocacy, although timely and informative, often appealed to emotions and values using anecdotes and strong criticism of authorities and other scientists. Many tweets received hundreds or thousands of likes. Risks were emphasized about children's vulnerability, Long COVID, variant severity, and Mpox, and via comparisons with human immunodeficiency viruses (HIV). Far-reaching policies and promotion of remedies were advocated without systematic evidence review, or sometimes, core field expertise. We identified potential conflicts of interest connected to private companies. Our study documents a need for public health debates to be less polarizing and judgmental, and more factual. In order to protect public trust in science during a crisis, we suggest the development of mechanisms to ensure ethical guidelines for engagement in "science-based" advocacy, and consideration of cost-benefit analysis of recommendations for public health decision-making.

No evidence that ACE2 or TMPRSS2 drive population disparity in COVID risks

Early in the SARS-CoV2 pandemic, in this journal, Hou et al. (BMC Med 18:216, 2020) interpreted public genotype data, run through functional prediction tools, as suggesting that members of particular human populations carry potentially COVID-risk-increasing variants in genes ACE2 and TMPRSS2 far more often than do members of other populations. Beyond resting on predictions rather than clinical outcomes, and focusing on variants too rare to typify population members even jointly, their claim mistook a well known artifact (that large samples reveal more of a population's variants than do small samples) as if showing real and congruent population differences for the two genes, rather than lopsided population sampling in their shared source data. We explain that artifact, and contrast it with empirical findings, now ample, that other loci shape personal COVID risks far more significantly than do ACE2 and TMPRSS2-and that variation in ACE2 and TMPRSS2 per se unlikely exacerbates any net population disparity in the effects of such more risk-informative loci.

How to understand the overlap of long COVID, chronic fatigue syndrome/myalgic encephalomyelitis, fibromyalgia and irritable bowel syndromes

Long COVID should be limited to patients with multiple, persistent symptoms not related to well-defined organ damage. Once redefined, a focused review of long COVID demonstrates striking similarity to chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), fibromyalgia (FM) and irritable bowel syndrome (IBS). Research in long COVID has revealed similar findings to those noted in CFS/ME and FM, characterized by central nervous system organ dysfunction. Long COVID, like CFS/ME, FM and IBS, is best understood as a bidirectional mind-body, neuroimmune illness.

Epidemiological and clinical characteristics of long COVID-19 among Iranians: A community-based study in southern Iran

BACKGROUND

The study aimed to evaluate the prevalence and pattern of long COVID-19 (LC) symptoms among individuals who had contracted COVID-19, to calculate the incidence of LC, and to provide insights into risk factors associated with developing LC in this population.

METHODS

This population-based cross-sectional survey was conducted in Fars province in 2023. Adult participants with a history of COVID-19 were recruited using a cluster random sampling method, alongside a control group with similar characteristics through the same methodology. Data were collected through in-person interviews using two researcher-developed data collection forms focused on demographic and clinical information.

RESULTS

A total of 2010 participants, comprising 1561 (77.7%) and 449 (22.3%) individuals with and without a previous history of COVID-19 were included. Among those with COVID-19 history, the prevalence of experiencing any symptoms was 93.7% (95% CI of 92.3%-94.8%) during the disease acute phase and 36.4% (95% CI of 34.0%-38.8%) after recovery. The incidence of symptoms specifically related to COVID-19, calculated by comparing the symptom rates between participants with and without a history of COVID-19, was found to be 13%. Factors such as older age, previous hospitalization for COVID-19, presence of cardiovascular disease, and use of steroids/chemotherapy were associated with LC symptoms.

CONCLUSIONS

Our investigation sheds light on long-term aspects of COVID-19, demonstrating a significant prevalence of LC with diverse manifestations. It also underscores the importance of establishing standardized criteria and control groups in research on LC to address challenges related to heterogeneity and potential overestimation of symptoms.

Prevalence of long COVID in the general adult population according to different definitions and sociodemographic and infection characteristics. A nationwide random sampling survey in France in autumn 2022

OBJECTIVES

Long COVID has been recognized since early 2020, but its definition is not unanimous, which complicates epidemiological assessments. This study estimated the prevalence of long COVID based on several definitions and severity thresholds in the adult population of mainland France and examined variations according to sociodemographic and infection characteristics.

METHODS

A cross-sectional survey using random sampling was conducted in August-November 2022. Participants declaring SARS-CoV-2 infection were assessed for infection dates and context, post-COVID symptoms (from a list of 31, with onset time, daily functioning impact, and alternative diagnosis), and perceived long COVID. Long COVID prevalence was estimated according to the WHO, National Institute for Health and Care Excellence, United States National Centre for Health Statistics, and United Kingdom Office for National Statistics definitions.

RESULTS

Of 10 615 participants, 5781 (54.5%) reported SARS-CoV-2 infection, with 123-759 (1.2-13.4%) having long COVID, depending on the definition. The prevalence of WHO post-COVID condition (PCC) was 4.0% (95% CI: 3.6-4.5) in the overall population and 8.0% (95% CI: 7.0-8.9) among infected individuals. Among the latter, the prevalence varied from 5.3% (men) to 14.9% (unemployed) and 18.6% (history of hospitalization for COVID-19). WHO-PCC overlapped poorly with other definitions (kappa ranging from 0.18 to 0.59) and perceived long COVID (reported in only 43% of WHO-PCC).

DISCUSSION

Regardless of its definition, long COVID remains a significant burden in the French adult population that deserves surveillance, notably for forms that strongly impact daily activities. More standardized definitions will improve integrated surveillance of, and better research on, long COVID.

Psychiatric Symptoms, Treatment Uptake, and Barriers to Mental Health Care Among US Adults With Post-COVID-19 Condition

Importance

Psychiatric symptoms are reportedly common among adults with post-COVID-19 condition (PCC). However, nationally representative data regarding symptom prevalence, treatment uptake, and barriers to care are needed to inform the development of care models.

Objectives

To evaluate the prevalence of psychiatric symptoms in US adults with PCC compared with those without PCC and assess treatment uptake and cost-related barriers to treatment.

Design, Setting, and Participants

Data from the 2022 National Health Interview Survey (NHIS), a nationally representative US cross-sectional survey, were analyzed between October 2023 and February 2024.

Exposure

Current PCC, defined as new symptoms following SARS-CoV-2 infection lasting more than 3 months and ongoing at the time of interview.

Main Outcomes and Measures

Depression symptoms were evaluated by the Patient Health Questionnaire-8 and anxiety symptoms were assessed using the General Anxiety Disorder-7 instrument. Participants were classified as having received treatment if they received mental health counseling or therapy or medications for mental health. Sleep difficulties, cognitive difficulties, disabling fatigue, and cost-related barriers were assessed from additional NHIS questions.

Results

Of the 25 122 participants representing approximately 231 million US adults (median [IQR] age, 46 [32-61] years; 49.8% male and 50.2% female participants), a weighted prevalence (wPr) of 3.4% (95% CI, 3.1%-3.6%) had current PCC. Compared with other US adults, participants with current PCC were more likely to have depression symptoms (wPr, 16.8% vs 7.1%; adjusted odds ratio [AOR], 1.96; 95% CI, 1.51-2.55), anxiety symptoms (wPr, 16.7% vs 6.3%; AOR, 2.21; 95% CI, 1.53-3.19), sleep difficulties (wPr, 41.5% vs 22.7%; AOR 1.95; 95% CI, 1.65-2.29), cognitive difficulties (wPr, 35.0% vs 19.5%; AOR, 2.04; 95% CI, 1.66-2.50), and disabling fatigue (wPr, 4.0% vs 1.6%; AOR, 1.85; 95% CI, 1.20-2.86). Among participants who had depression or anxiety symptoms, those with PCC had a similar likelihood of not having received treatment (wPr, 28.2% vs 34.9%; AOR, 1.02; 95% CI, 0.66-1.57). However, participants with current PCC were more likely to report a cost-related barrier to accessing mental health counseling or therapy (wPr, 37.2% vs 23.3%; AOR, 2.05; 95% CI, 1.40-2.98).

Conclusions and Relevance

The findings of this study suggest that people with PCC have a higher prevalence of psychiatric symptoms than other adults but are more likely to experience cost-related barriers to accessing therapy. Care pathways for PCC should consider prioritizing mental health screening and affordable treatment.

[SARS-CoV-2 infection and autoimmunity]

Even in the early phase of the corona pandemic in 2020, severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) was referred to as an "autoimmune virus". Since then, there have been numerous reports on the increased incidence of autoantibodies and autoimmune phenomena after SARS-CoV‑2 infections. On the one hand, autoantibodies can influence the course of the disease and on the other hand, they can lead to the first manifestation of new autoimmune diseases. In addition, a role of autoantibodies in the pathogenesis of post-coronavirus disease (post-COVID) is discussed. In the present review article, important aspects and studies are listed and the possible therapeutic consequences resulting from the findings are presented.

Whole-Body Cryostimulation in Post-COVID Rehabilitation for Patients with Obesity: A Multidisciplinary Feasibility Study

BACKGROUND

A post-COVID condition can reduce activity and quality of life, resulting in a significant socioeconomic and health burden. Understanding its impact on patients' health is important for the development of personalized rehabilitation interventions. An independent association between obesity and post-COVID condition was found because of complications and comorbidities.

METHODS

Sixteen patients with obesity and post-COVID symptoms (i.e., dyspnea, pain, poor sleep quality, muscle fatigue), admitted to the Istituto Auxologico Italiano, Piancavallo (VB), Italy, were recruited for a four-week rehabilitation program including conventional exercise therapy, nutritional intervention, psychological support and whole-body cryostimulation (WBC).

RESULTS

All participants attended all sessions of the program. Anthropometric data showed statistically significant changes in weight, waist circumference and body mass index. Biochemical analyses showed significant reductions in lipid and inflammatory profiles. There was a significant improvement in physical performance, reduction in pain and improvement in psychological well-being.

CONCLUSION

A multidisciplinary rehabilitation protocol including WBC, designed for patients with obesity and a post-COVID condition, is safe and feasible. The overall improvements demonstrate that multidisciplinary rehabilitation was effective on post COVID patients and suggest that the use of WBC is safe and could play a role as a booster in rehabilitation programs.

The potential clinical impact and cost-effectiveness of the updated COVID-19 mRNA fall 2023 vaccines in the United States

AIMS

To assess the potential clinical impact and cost-effectiveness of COVID-19 mRNA vaccines updated for fall 2023 in adults aged ≥18 years over a 1-year analytic time horizon (September 2023-August 2024).

MATERIALS AND METHODS

A compartmental Susceptible-Exposed-Infected-Recovered model was updated to reflect COVID-19 cases in summer 2023. The numbers of symptomatic infections, COVID-19-related hospitalizations and deaths, and costs and quality-adjusted life-years (QALYs) gained were calculated using a decision tree model. The incremental cost-effectiveness ratio (ICER) of a Moderna updated mRNA fall 2023 vaccine (Moderna Fall Campaign) was compared to no additional vaccination. Potential differences between the Moderna and the Pfizer-BioNTech fall 2023 vaccines were also examined.

RESULTS

Base case results suggest that the Moderna Fall Campaign would decrease the expected 64.2 million symptomatic infections by 7.2 million (11%) to 57.0 million. COVID-19-related hospitalizations and deaths are expected to decline by 343,000 (-29%) and 50,500 (-33%), respectively. The Moderna Fall Campaign would increase QALYs by 740,880 and healthcare costs by $5.7 billion relative to no vaccine, yielding an ICER of $7700 per QALY gained. Using a societal cost perspective, the ICER is $2100. Sensitivity analyses suggest that vaccine effectiveness, COVID-19 incidence, hospitalization rates, and costs drive cost-effectiveness. With a relative vaccine effectiveness of 5.1% for infection and 9.8% for hospitalization for the Moderna vaccine versus the Pfizer-BioNTech vaccine, use of the Moderna vaccine is expected to prevent 24,000 more hospitalizations and 3300 more deaths than the Pfizer-BioNTech vaccine.

LIMITATIONS AND CONCLUSIONS

As COVID-19 becomes endemic, future incidence, including patterns of infection, are highly uncertain. The effectiveness of fall 2023 vaccines is unknown, and it is unclear when a new variant that evades natural or vaccine immunity will emerge. Despite these limitations, our model predicts the Moderna Fall Campaign vaccine is highly cost-effective across all sensitivity analyses.