Post-COVID-19 syndrome and humoral response association after one year in vaccinated and unvaccinated patients

Analysis of the Total Immunoglobulin G (IgG) and Its Subclasses Over Time in Coronavirus Disease 2019-Recovered Patients and Its Association With Disease Severity: A Single-Center Prospective Cohort Study

PURPOSE

In order to address concerns regarding the diminishing levels of antibodies over time and the variations in response between mild and severe cases, efforts are being made to determine how long immunoglobulin G (IgG) antibodies persist in patients with coronavirus disease 2019 (COVID-19).

METHODS

The present study was conducted in a longitudinal setting over a period of 6 months in 37 unvaccinated COVID-19-recovered patients. The spike protein and receptor-binding domain (RBD)-specific serum levels of IgG and IgG subclasses were measured at 3 time points (within ≤1 month, 1-3 months, and 3-6 months) of recovery from COVID-19.

FINDINGS

Our study found a significant (P < 0.05) reduction in the levels of antispike and anti-RBD antibodies within 3 to 6 months after recovery from COVID-19 infections. The group of patients who developed severe illness had higher levels of antispike and anti-RBD IgG compared with the group of patients who recovered from mild disease. There was a statistically significant difference in the contribution of IgG1 and IgG3 over time in COVID-19-recovered patients, indicating a potential alteration in the distribution of IgG subclasses. Serum levels of IgG1 were found to be 1.5 folds higher within 1 to 3 months of recovery from severe acute respiratory syndrome coronavirus 2 infections in severe cases than mild cases.

IMPLICATIONS

This study found that severe COVID-19 cases in unvaccinated patients had higher antibody titers and a greater likelihood of antispike antibodies persisting after infection. The levels of IgG1 and IgG3 increased significantly with the severity of COVID-19, indicating a heightened immune response in more severe cases. The estimation of serum levels of IgG subclass may determine the vaccination strategy and the process of treatment.

Long-Term Anti-SARS-CoV-2 IgG Antibody Levels in Vaccinated Diabetes Patients After Recovery From COVID-19

BACKGROUND

Long-term persistence of anti-SARS-CoV-2 IgG antibodies is critical to protect against SARS-CoV-2 infection or to alleviate the severity of COVID-19. However, the persistence of anti-SARS-CoV-2 IgG after infection in vaccinated diabetes patients is unclear. This study aimed to investigate levels of anti-SARS-CoV-2 IgG 1 year after SARS-CoV-2 infection in diabetes patients.

METHODS

This study was conducted between December 2023 and January 2024. Participants with SARS-CoV-2 infection during December 2022 to January 2023 were included, and were classified into the diabetes group and non-diabetes group. Anti-N/S IgG antibodies were measured with chemiluminescence immunoassay.

RESULTS

A total of 500 participants, 265 diabetes and 235 non-diabetes patients, were included. Anti-N/S IgG levels in the diabetes group were significantly lower than those in the non-diabetes group (1.92 ± 0.58 vs. 2.08 ± 0.42 log10 AU/mL, p = 0.001). In vaccinated subjects, antibody levels in diabetes patients were also lower than those in non-diabetic patients. After adjustment for sex, age, body mass index, estimated glomerular filtration rate, hypertension, and heart disease, diabetes was negatively correlated with antibody titres (β = -0.16, 95% confidence interval (CI) -0.26 to -0.06, p = 0.002). In the diabetes group, after adjustment for confounders, use of sodium-glucose cotransporter-2 inhibitors (SGLT-2i) was positively associated with high antibody levels (odds ratio 3.84, 95% CI 1.70-8.65, p = 0.001).

CONCLUSION

Vaccinated diabetes patients have lower anti-N/S IgG antibodies than non-diabetic patients 12 months after infection. SGLT-2i is associated with higher anti-N/S IgG antibody levels in diabetes patients.

Evidence on the associations and safety of COVID-19 vaccination and post COVID-19 condition: an updated living systematic review

Post COVID-19 condition (PCC) refers to persistent symptoms occurring ≥12 weeks after COVID-19. This living systematic review (SR) assessed the impact of vaccination on PCC and vaccine safety among those with PCC, and was previously published with data up to December 2022. Searches were updated to 31 January 2024 and standard SR methodology was followed. Seventy-eight observational studies were included (47 new). There is moderate confidence that two doses pre-infection reduces the odds of PCC (pooled OR (pOR) 0.69, 95% CI 0.64-0.74, I2 = 35.16%). There is low confidence for remaining outcomes of one dose and three or more doses. A booster dose may further reduce the odds of PCC compared to only a primary series (pOR 0.85, 95% CI 0.74-0.98, I2 = 16.85%). Among children ≤18 years old, vaccination may not reduce the odds (pOR 0.79, 95% CI 0.56-1.11, I2 = 37.2%) of PCC. One study suggests that vaccination within 12 weeks post-infection may reduce the odds of PCC. For those with PCC, vaccination appears safe (four studies) and may reduce the odds of PCC persistence (pOR 0.73, 95% CI 0.57-0.92, I2 = 15.5%).

Anti-SARS-CoV-2 Antibodies in Long-COVID-Markers of Protection or Elevated Risk? A Systematic Review

Long-COVID affects a significant number of COVID-19 survivors, profoundly impacting daily life and work. Although research suggests a potential link between antibody levels and long-COVID risk, findings remain inconclusive. Understanding antibody dynamics could support the identification of patients at risk, improve long-COVID diagnosis, and guide protective strategies such as vaccination. Despite growing evidence, no systematic review has yet evaluated the current literature on this topic. We therefore aimed to synthesise and evaluate existing evidence on the association between anti-SARS-CoV-2 antibody titres and long-COVID, with the goal of clarifying their potential role in predicting long-COVID risk, guiding patient management, and informing future research directions. Studies published in PubMed/Medline databases between January 2020 and October 2024 were included without language restrictions. Studies on body fluids other than serum/blood were excluded. Study selection and quality assessment was conducted independently by two researchers. After screening 949 studies, 58 studies encompassing 53,739 individuals, and 7812 long-COVID patients, were included. Evidence was highly heterogenous but most studies reported an association between anti-SARS-CoV-2-spike antibodies and long-COVID, although the nature of the association appeared to be dependent on time from acute infection. Low anti-SARS-CoV-2-spike antibodies during acute COVID-19 were associated with increased risk of long-COVID. The association between low anti-SARS-CoV-2-spike antibodies during acute COVID-19 and long-COVID suggests that maintaining sufficiently high antibody levels may be protective. However, the current evidence level is low and further studies with sufficient power are required to confirm this association and to potentially determine protective cutoffs.

Effect of COVID-19 vaccination on the risk of developing post-COVID conditions: The VENUS study

INTRODUCTION

Post-COVID-19 conditions have emerged as a global health challenge. This study examined the long-term effects of COVID-19 vaccination on the incidence and risk of post-COVID-19 conditions in Japan.

METHODS

This retrospective cohort study was conducted using a database comprising medical claims, COVID-19 case information, and vaccination records of persons residing in four Japanese municipalities. The cohort included COVID-19 cases diagnosed between August 2020 and December 2022. Participants were classified according to the duration between their most recent COVID-19 vaccination and COVID-19 occurrence (≥365 days, 150-364 days, and 14-149 days). The incidences of 36 post-COVID-19 conditions were monitored for 3, 5, and 8 months after infection. Cox proportional hazards models were used to calculate the risk of developing each post-COVID-19 condition within 8 months after infection according to vaccination status.

RESULTS

From among 84,464 participants, 9642 (11.4 %) developed post-COVID-19 conditions over 8 months. The 8-month risks of developing 28 (including various respiratory conditions, cardiovascular conditions, inflammatory and immune diseases, physical conditions, psychiatric conditions, and endocrine disorders) of the 36 target conditions were significantly lower when individuals had been recently vaccinated (14-149 days) before infection.

CONCLUSIONS

COVID-19 vaccination can reduce the incidence and risk of post-COVID-19 conditions if administered within 5 months before infection. Despite having the highest mean age and prevalence of comorbidities, individuals who were most recently vaccinated had a lower risk of developing post-COVID-19 conditions. These results provide important evidence for future COVID-19 vaccination strategies.

Persistence of Long COVID Symptoms Two Years After SARS-CoV-2 Infection: A Prospective Longitudinal Cohort Study

BACKGROUND/OBJECTIVES

Millions of individuals worldwide continue to experience symptoms following SARS-CoV-2 infection. This study aimed to assess the prevalence and phenotype of multi-system symptoms attributed to Long COVID-including fatigue, pain, cognitive-emotional disturbances, headache, cardiopulmonary issues, and alterations in taste and smell-that have persisted for at least two years after acute infection, which we define as "persistent Long COVID". Additionally, the study aimed to identify clinical features and blood biomarkers associated with persistent Long COVID symptoms.

METHODS

We sent a detailed long COVID symptoms questionnaire to an existing cohort of 1258 vaccinated adults (age 18-79 years) who had mild infection (e.g., non-hospitalized) SARS-CoV-2 Delta variant 2 years earlier. These individuals had comprehensive datasets, including blood samples, available for further analysis. We estimated prevalence of persistent long COVID two years post-infection using weighted adjustment (Horvitz-Thompson estimator) to overcome reporting bias. Multivariable logistic regression models were used to determine association of clinical features and blood biomarkers (pre-infection SARS-CoV-2 RBD-IgG, SARS-CoV-2 neutralizing antibodies, and pre-infection and post-infection neurofilament light) with prevalence of persistent long COVID.

RESULTS

N = 323 participants responded to the survey, of whom N = 74 (23%) reported at least one long COVID symptom that had persisted for two years after the acute infection. Weighted prevalence of persistent long COVID symptoms was 21.5% (95% CI = 16.7-26.3%). Female gender, smoking, and severity of acute COVID-19 infection were significantly associated with persistent Long COVID. The blood biomarkers assessed were not significantly associated with persistent Long COVID.

CONCLUSIONS

Among vaccinated adults two years after mild infection with Delta variant SARS-CoV-2, persistent symptoms attributed to Long COVID are extremely common, certain subgroups are at higher risk, and further research into biological mechanisms and potential treatment targets is needed.

COVID-19 vaccination and long COVID among 50 years older and above European: The role of chronic multimorbidity

BACKGROUND AND AIMS

We aimed to explore the association between coronavirus disease-19 (COVID-19) vaccination and long COVID according to the status of chronic multimobidity.

METHODS

A total of 1913 participants were recruited in the cross-sectional study on the basis of the Survey of Health and Retirement in Europe. COVID-19 vaccination was defined as vaccination within the last 12 months. Chronic multimorbidity was defined as history of 2 + chronic disease. The study outcome was long COVID during the 12-month follow-up. Multivariable logistic models were performed to estimate the influence of chronic multimorbidity on the association of vaccination with long COVID. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated.

RESULTS

Chronic multimorbidity significantly modified the association of COVID-19 vaccination with long COVID (Pinteraction = 0.024). The rates of study outcome were significantly lower among vaccinated participants in the chronic multimorbidity subgroup, but not in the other subgroup. Multivariable odds ratios (95 % confidence intervals) of study outcome for unvaccination vs. vaccination were 1.494 (1.013-2.203) in those with multimorbidity and 0.915 (0.654-1.280) in those without multimorbidity, respectively. Adding COVID-19 vaccination to a model containing conventional risk factors significantly improved risk reclassification for study outcome among those with chronic multimobidity (continuous NRI was 25.39 % [P = 0.002] and IDI was 0.42 % [P = 0.075]) CONCLUSION: An inverse association of COVID-19 vaccination with long COVID was found among participants with chronic multimorbidity, but not among those without chronic multimorbidity. Chronic multimorbidity might expand the influence of unvaccination on developing long COVID among European aged ≥50 years.

A Case Report of Long COVID or Post-COVID-19 Symptoms and Characteristics

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a global health crisis. Long COVID refers to a debilitating condition characterized by severe symptoms that may arise after the initial acute phase of COVID-19. Significant attention has been directed toward the acute phase of the respiratory system while overshadowing the understanding and management of long-term complications, often referred to as "long COVID." This case focuses on a 19-year-old female who experienced the multisystemic manifestation of COVID-19 syndrome several months after the initial infection, spanning cardiovascular, respiratory, endocrine, central nervous system, and multi-skeletal domains. This study aims to describe the patient's experience and recovery process with a specific emphasis on the long COVID experience.

Specific sequelae symptoms of COVID-19 of Omicron variant in comparison with non-COVID-19 patients: a retrospective cohort study in Japan

Background

The specific long-term sequela of coronavirus disease 2019 (COVID-19), also known as long COVID of the Omicron variant remain unclear, due to a lack of cohort studies that include non-COVID patients with cold-like symptoms. The study was conducted to examine specific sequelae symptoms after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, which is considered the Omicron variant, compared with patients who were never-infected.

Methods

In this retrospective cohort study, we sent questionnaires in November 2022, targeting those who visited our fever outpatient unit of a single institution from July to September 2022. SARS-CoV-2 infection status was determined by SARS-CoV-2 polymerase chain reaction (PCR) test results during the study period collected in electronic medical records. Clinical characteristics at 30 days or more since the date of SARS-CoV-2 PCR test were assessed by the questionnaires. Multiple logistic regression was performed to investigate the independent association between SARS-CoV-2 infection and possible sequelae symptoms.

Results

In total, valid responses were received from 4,779 patients (mean age: 41.4 years, standard deviation: 19.8 years old). Among them, 3,326 (69.6%) and 1,453 (30.4%) were SARS-CoV-2 PCR test positive and never-infected, respectively. We found that patients with SARS-CoV-2 infection were more likely to have a loss of taste or smell [odds ratio (OR) 4.55, 95% confidence interval (CI): 1.93, 10.71], hair loss (OR 3.19, 95% CI: 1.67, 6.09), neurocognitive symptoms (OR 1.95, 95% CI: 1.43, 2.65), and respiratory symptoms (OR 1.23, 95% CI: 1.03, 1.47) than never-infected patients. SARS-CoV-2 infection was not associated with common cold symptoms, chronic physical distress, or diarrhea as sequelae symptoms. Further, SARS-CoV-2 vaccination showed protective effects on sequelae of loss of taste or smell and hair loss.

Conclusions

Loss of taste or smell, hair loss, neurocognitive symptoms, and respiratory symptoms were found to be specific sequelae of the SARS-CoV-2 Omicron variant. It is important not to miss these symptoms that follow SARS-CoV-2 infection and to recognize and manage the long COVID.

Incidence and risk factors of post COVID-19 syndrome: a Tunisian cohort study

BACKGROUND

It has become increasingly clear that SARS-CoV-2 infection can lead to persistent physical and mental health problems lasting weeks or months, requiring prolonged periods of clinical care and increasing the burden on the healthcare system. This phenomenon, known as post COVID-19 syndrome (PCS), is a relatively new condition, its incidence is still unclear and differs between studies.

OBJECTIVES

In this cohort study, we aimed to estimate the incidence of PCS and to identify its risk factors in the Tunisian population.

METHODS

This is a prospective cohort study that enrolled patients diagnosed with COVID-19 from the triage unit of the University Hospital of Monastir, Tunisia. between April 2021 and June 2022. Patients were contacted by phone for a follow-up evaluation of PCS 12- weeks after the diagnosis date.

RESULTS

A total of 1451 individuals diagnosed with COVID-19 during the study period, responded to the follow-up evaluation after 3 months. The incidence of PCS was found to be 44.03% (95% CI [41.47; 46.58]), with fatigue being the most common symptom (21.5%), followed by cognitive impairment (10.3%), including memory loss and difficulty concentrating. Multivariate analysis revealed that the main associated factors to PCS were female gender (RR = 1.54; CI95% [1.30 - 1.82]), pre-existing comorbidities (RR = 1.30; CI95% [1.10 - 1.52]), duration of acute COVID-19 illness (days) (RR = 1.02; CI95% [1.01 - 1.03]), hospitalization (RR = 1.27; CI95% [1.05 - 1.53]), number of COVID-19 episodes (RR = 1.46; CI 95% [1.28 - 1.67]) and patients having receive two or more doses of vaccine prior to COVID-19 infection (RR = 0.82; CI95% [0.70 - 0.96]).

CONCLUSION

Our study allowed to estimate the incidence and identify risk factors of PCS. Recognizing these factors could help to better understand the underlying mechanisms and guide interventions for prevention and management of this condition.

Serological markers and long COVID-A rapid systematic review

BACKGROUND

Long COVID is highly heterogeneous, often debilitating, and may last for years after infection. The aetiology of long COVID remains uncertain. Examination of potential serological markers of long COVID, accounting for clinical covariates, may yield emergent pathophysiological insights.

METHODS

In adherence to PRISMA guidelines, we carried out a rapid review of the literature. We searched Medline and Embase for primary observational studies that compared IgG response in individuals who experienced COVID-19 symptoms persisting ≥12 weeks post-infection with those who did not. We examined relationships between serological markers and long COVID status and investigated sources of inter-study variability, such as severity of acute illness, long COVID symptoms assessed and target antigen(s).

RESULTS

Of 8018 unique records, we identified 29 as being eligible for inclusion in synthesis. Definitions of long COVID varied. In studies that reported anti-nucleocapsid (N) IgG (n = 10 studies; n = 989 participants in aggregate), full or partial anti-Spike IgG (i.e. the whole trimer, S1 or S2 subgroups, or receptor binding domain, n = 19 studies; n = 2606 participants), or neutralizing response (n = 7 studies; n = 1123 participants), we did not find strong evidence to support any difference in serological markers between groups with and without persisting symptoms. However, most studies did not account for severity or level of care required during acute illness, and other potential confounders.

CONCLUSIONS

Pooling of studies would enable more robust exploration of clinical and serological predictors among diverse populations. However, substantial inter-study variations hamper comparability. Standardized reporting practices would improve the quality, consistency and comprehension of study findings.

The Course of COVID-19 and Long COVID: Identifying Risk Factors among Patients Suffering from the Disease before and during the Omicron-Dominant Period

SARS-CoV-2 has acquired many mutations that influence the severity of COVID-19's course or the risk of developing long COVID. In 2022, the dominant SARS-CoV-2 variant was Omicron. This study aimed to compare the course of COVID-19 in the periods before and during the dominance of the Omicron variant. Risk factors for developing long COVID were also assessed. This study was based on stationary visits of patients after COVID-19 and follow-up assessments after 3 months. Clinical symptoms, comorbidities, and vaccination status were evaluated in 1967 patients. Of the analyzed group, 1308 patients (66.5%) were affected by COVID-19 in the period before the Omicron dominance. The prevalence of long COVID was significantly lower among patients of the Omicron group (47.7% vs. 66.9%, p < 0.001). The risk of long COVID was higher for women (OR: 1.61; 95% CI: 1.31, 1.99]) and asthmatics (OR: 1.46; 95% CI: 1.03, 2.07]). Conclusively, infection during the Omicron-dominant period was linked to a lower risk of developing long COVID. Females are at higher risk of developing long COVID independent of the pandemic period. Individuals affected by COVID-19 in the Omicron-dominant period experience a shorter duration of symptoms and reduced frequency of symptoms, except for coughing, which occurs more often.

Damage to endothelial barriers and its contribution to long COVID

The world continues to contend with COVID-19, fueled by the emergence of viral variants. At the same time, a subset of convalescent individuals continues to experience persistent and prolonged sequelae, known as long COVID. Clinical, autopsy, animal and in vitro studies all reveal endothelial injury in acute COVID-19 and convalescent patients. Endothelial dysfunction is now recognized as a central factor in COVID-19 progression and long COVID development. Different organs contain different types of endothelia, each with specific features, forming different endothelial barriers and executing different physiological functions. Endothelial injury results in contraction of cell margins (increased permeability), shedding of glycocalyx, extension of phosphatidylserine-rich filopods, and barrier damage. During acute SARS-CoV-2 infection, damaged endothelial cells promote diffuse microthrombi and destroy the endothelial (including blood-air, blood-brain, glomerular filtration and intestinal-blood) barriers, leading to multiple organ dysfunction. During the convalescence period, a subset of patients is unable to fully recover due to persistent endothelial dysfunction, contributing to long COVID. There is still an important knowledge gap between endothelial barrier damage in different organs and COVID-19 sequelae. In this article, we mainly focus on these endothelial barriers and their contribution to long COVID.

Preinfection Neutralizing Antibodies, Omicron BA.5 Breakthrough Infection, and Long COVID: A Propensity Score-Matched Analysis

BACKGROUND

Data are limited on the role of preinfection humoral immunity protection against Omicron BA.5 infection and long coronavirus disease (COVID) development.

METHODS

We conducted nested case-control analysis among tertiary hospital staff in Tokyo who donated blood samples in June 2022 (1 month before Omicron BA.5 wave), approximately 6 months after receiving a third dose of COVID-19 mRNA vaccine. We measured live virus-neutralizing antibody titers against wild type and Omicron BA.5, and anti-receptor-binding domain (RBD) antibody titers at preinfection, and compared them between cases and propensity-matched controls. Among the breakthrough cases, we examined association between preinfection antibody titers and incidence of long COVID.

RESULTS

Preinfection anti-RBD and neutralizing antibody titers were lower in cases than controls. Neutralizing titers against wild type and Omicron BA.5 were 64% (95% confidence interval [CI], 42%-77%) and 72% (95% CI, 53%-83%) lower, respectively, in cases than controls. Individuals with previous Omicron BA.1/BA.2 infections were more frequent among controls than cases (10.3% vs 0.8%), and their Omicron BA.5 neutralizing titers were 12.8-fold higher than infection-naive individuals. Among cases, preinfection antibody titers were not associated with incidence of long COVID.

CONCLUSIONS

Preinfection immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play a role in protecting against the Omicron BA.5 infection but not preventing long COVID.

Association between sleep duration and antibody acquisition after mRNA vaccination against SARS-CoV-2

Introduction

Sleep enhances the antibody response to vaccination, but the relationship between sleep and mRNA vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not fully understood.

Methods

In this prospective observational study, we investigated the influence of sleep habits on immune acquisition induced by mRNA vaccines against SARS-CoV-2 in 48 healthy adults (BNT-162b2, n=34; mRNA-1273, n=14; female, n=30, 62.5%; male, n=18, 37.5%; median age, 39.5 years; interquartile range, 33.0-44.0 years) from June 2021 to January 2022. The study measured sleep duration using actigraphy and sleep diaries, which covered the periods of the initial and booster vaccinations.

Results

Multivariable linear regression analysis showed that actigraphy-measured objective sleep duration 3 and 7 days after the booster vaccination was independently and significantly correlated with higher antibody titers (B=0.003; 95% confidence interval, 0.000-0.005; Beta=0.337; p=0.02), even after controlling for covariates, including age, sex, the type of vaccine, and reactogenicity to the vaccination. Associations between acquired antibody titer and average objective sleep duration before vaccination, and any period of subjective sleep duration measured by sleep diary were negligible.

Discussion

Longer objective, but not subjective, sleep duration after booster vaccination enhances antibody response. Hence, encouraging citizens to sleep longer after mRNA vaccination, especially after a booster dose, may increase protection against SARS-CoV-2.

Study registration

This study is registered at the University Hospital Medical Information Network Center (UMIN: https://www.umin.ac.jp) on July 30, 2021, #UMIN000045009.

Mechanisms of long COVID: An updated review

The coronavirus disease 2019 (COVID-19) pandemic has been ongoing for more than 3 years, with an enormous impact on global health and economies. In some patients, symptoms and signs may remain after recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which cannot be explained by an alternate diagnosis; this condition has been defined as long COVID. Long COVID may exist in patients with both mild and severe disease and is prevalent after infection with different SARS-CoV-2 variants. The most common symptoms include fatigue, dyspnea, and other symptoms involving multiple organs. Vaccination results in lower rates of long COVID. To date, the mechanisms of long COVID remain unclear. In this narrative review, we summarized the clinical presentations and current evidence regarding the pathogenesis of long COVID.

Lessons learnt while designing and conducting a longitudinal study from the first Italian COVID-19 pandemic wave up to 3 years

BACKGROUND

Several scientific contributions have summarized the "lessons learnt" during the coronavirus disease 2019 (COVID-19) pandemic, but only a few authors have discussed what we have learnt on how to design and conduct research during a pandemic. The main intent of this study was to summarize the lessons learnt by an Italian multidisciplinary research group that developed and conducted a longitudinal study on COVID-19 patients infected during the first wave in March 2020 and followed-up for 3 years.

METHODS

A qualitative research approach embedded into the primary CORonavirus MOnitoRing study (CORMOR) study was developed, according to the the consolidated criteria for reporting qualitative research. Multiple data collection strategies were performed: each member was invited to report the main lessons learnt according to his/her perspective and experience from the study design throughout its conduction. The narratives collected were summarized and discussed in face-to-face rounds. The narratives were then thematically analysed according to their main topic in a list that was resent to all members to check the content and their organization. The list of the final "lessons learnt" has been agreed by all members, as described in a detailed fashion.

RESULTS

Several lessons were learnt while designing and conducting a longitudinal study during the COVID-19 pandemic and summarised into ten main themes: some are methodological, while others concern how to conduct research in pandemics/epidemics/infectious disease emergencies.

CONCLUSIONS

The multidisciplinary approach, which also included patients' perspective, helped us to protect the consistency and quality of the research provided in pandemic times. The lesson learnt suggest that our research approach may benefit from changes in education, clinical practice and policies.

15-month post-COVID syndrome in outpatients: Attributes, risk factors, outcomes, and vaccination status - longitudinal, observational, case-control study

Background

While the short-term symptoms of post-COVID syndromes (PCS) are well-known, the long-term clinical characteristics, risk factors and outcomes of PCS remain unclear. Moreover, there is ongoing discussion about the effectiveness of post-infection vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) to aid in PCS recovery.

Methods

In this longitudinal and observational case-control study we aimed at identifying long-term PCS courses and evaluating the effects of post-infection vaccinations on PCS recovery. Individuals with initial mild COVID-19 were followed for a period of 15 months after primary infection. We assessed PCS outcomes, distinct symptom clusters (SC), and SARS-CoV-2 immunoglobulin G (IgG) levels in patients who received SARS-CoV-2 vaccination, as well as those who did not. To identify potential associating factors with PCS, we used binomial regression models and reported the results as odds ratios (OR) with 95% confidence intervals (95%CI).

Results

Out of 958 patients, follow-up data at 15 month after infection was obtained for 222 (23.2%) outpatients. Of those individuals, 36.5% (81/222) and 31.1% (69/222) were identified to have PCS at month 10 and 15, respectively. Fatigue and dyspnea (SC2) rather than anosmia and ageusia (SC1) constituted PCS at month 15. SARS-CoV-2 IgG levels were equally distributed over time among age groups, sex, and absence/presence of PCS. Of the 222 patients, 77.0% (171/222) were vaccinated between 10- and 15-months post-infection, but vaccination did not affect PCS recovery at month 15. 26.3% of unvaccinated and 25.8% of vaccinated outpatients improved from PCS (p= .9646). Baseline headache (SC4) and diarrhoea (SC5) were risk factors for PCS at months 10 and 15 (SC4: OR 1.85 (95%CI 1.04-3.26), p=.0390; SC5: OR 3.27(95%CI 1.54-6.64), p=.0009).

Conclusion

Based on the specific symptoms of PCS our findings show a shift in the pattern of recovery. We found no effect of SARS-CoV-2 vaccination on PCS recovery and recommend further studies to identify predicting biomarkers and targeted PCS therapeutics.

A systematic review of the evidence on the associations and safety of COVID-19 vaccination and post COVID-19 condition

Post COVID-19 condition (PCC) refers to persistent or recurring symptoms (>8 weeks) occurring ≤12 weeks following acute COVID-19. The objective of this systematic review was to assess the evidence on the risk of PCC with vaccination before or after COVID-19 or after developing PCC, and the safety of vaccination among those already experiencing PCC. A search was conducted up to 13 December 2022 and standard systematic review methodology was followed. Thirty-one observational studies were included. There is moderate confidence that two doses of vaccine given pre-infection reduced the odds of PCC (pooled OR (pOR) 0.67, 95% CI 0.60-0.74, I2 = 59.9%), but low confidence that one dose may not reduce the odds (pOR 0.64, 95% CI 0.31#x2013;1.31, I2 = 99.2%), and the evidence is very uncertain about the effect of three doses (pOR 0.45, 95% CI 0.10#x2013;1.99, I2 = 30.9%). One of three studies suggested vaccination shortly after COVID-19 may offer additional protection from developing PCC compared to unvaccinated individuals, but this evidence was very uncertain. For those with PCC, vaccination was not associated with worsening PCC symptoms (10 studies) and appears safe (3 studies), but it is unclear if vaccination may change established PCC symptoms.

Post-COVID-19 Syndrome 2 Years After the First Wave: The Role of Humoral Response, Vaccination and Reinfection

Background

The aim of this study was to describe the long-term evolution of post-COVID-19 syndrome over 2 years after the onset of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in survivors of the first wave.

Methods

This prospective study was based on interviews and investigated post-COVID-19 syndrome 6, 12, and 24 months after the disease onset in all adult in- and outpatients with COVID-19 followed at Udine Hospital (Italy) during the first wave (March-May 2020). Humoral response, vaccination status, and reinfection were assessed.

Results

Overall, 230 patients (53.5% female; mean age 54.7 years) were interviewed 2.3 years (standard deviation = 0.11) after acute onset. Post-COVID-19 syndrome was observed in 36.1% of patients (n = 83) at 2 years. The most common persistent symptoms were fatigue (14.4%), rheumatological (14.4%), and psychiatric symptoms (9.6%). Overall, 55.4% (46 of 83) of long haulers searched for healthcare system support and 21 (45.7%) were visited by a specialist. Female gender (odds ratio [OR] = 2.50, P = .005), a proportional increase in the number of symptoms during acute COVID-19 (OR = 1.40, P = .001), and the presence of comorbidities (OR = 1.57, P = .004) were all independent risk factors for post-COVID-19 syndrome. Vaccination and reinfection had no impact on post-COVID-19 syndrome dynamics. The presence of receptor-binding domain (RBD) SARS-CoV-2 immunoglobulin G (IgG) and non-RBD SARS-CoV-2 IgG titers were not associated with the occurrence of post-COVID-19 syndrome.

Conclusions

Two years after COVID-19, the burden of persistent symptoms remains high among in- and outpatients' population infected during the first wave. Post-COVID-19 dynamic does not seem to be influenced by SARS-CoV-2 immunization status and reinfection.

Promising Markers of Inflammatory and Gut Dysbiosis in Patients with Post-COVID-19 Syndrome

Post-COVID-19 syndrome is a complex of different symptoms, which results in a multisystemic impairment after the suffering from COVID-19 infection. The aim of the study was to reveal the clinical, laboratory, and gut disorders in patients with post-COVID-19 syndrome (n = 39) before and after taking part in the 14-day complex program of rehabilitation. A complete blood count, coagulation test, blood chemistry, biomarkers, and metabolites in serum samples, and gut dysbiosis were revealed in patients on the day of admission and after 14-day rehabilitation, in comparison with the variables of healthy volunteers (n = 48) or with reference ranges. On the day of discharge, patients noted an improvement in respiratory function, general well-being, and mood. At the same time, the levels of some metabolic (4-hydroxybenzoic, succinic, fumaric acids) and inflammatory (interleukin-6) variables, which were increased on admission, did not reach the level of healthy people during the rehabilitation program. Taxonomy disbalance was observed in patients' feces, namely, a high level of total bacterial mass, a decrease in the number of Lactobacillus spp., and an increase in pro-inflammatory microorganisms. The authors suggest that the post-COVID-19 rehabilitation program should be personalized, considering the patient's state together with not only the baseline levels of biomarkers, but also with the individual taxonomy of the gut microbiota.

The Impact of Vaccination on COVID-19 Burden of Disease in the Adult and Elderly Population: A Systematic Review of Italian Evidence

COVID-19 is a major global health threat, with millions of confirmed cases and deaths worldwide. Containment and mitigation strategies, including vaccination, have been implemented to reduce transmission and protect the population. We conducted two systematic reviews to collect nonrandomized studies investigating the effects of vaccination on COVID-19-related complications and deaths in the Italian population. We considered studies conducted in Italian settings and written in English that contained data on the effects of vaccination on COVID-19-related mortality and complications. We excluded studies that pertained to the pediatric population. In total, we included 10 unique studies in our two systematic reviews. The results showed that fully vaccinated individuals had a lower risk of death, severe symptoms, and hospitalization compared to unvaccinated individuals. The review also looked at the impact of vaccination on post-COVID-19 syndrome, the effectiveness of booster doses in older individuals, and nationwide adverse events. Our work highlights the crucial role that vaccination campaigns have played in reducing the burden of COVID-19 disease in the Italian adult population, positively impacting the pandemic trajectory in Italy.

Protective effect of COVID-19 vaccination against long COVID syndrome: A systematic review and meta-analysis

BACKGROUND

The relationship between coronavirus disease 2019 (COVID-19) vaccination and long COVID has not been firmly established. We conducted a systematic review and meta-analysis to evaluate the association between COVID-19 vaccination and long COVID.

METHODS

PubMed and EMBASE databases were searched on September 2022 without language restrictions (CRD42022360399) to identify prospective trials and observational studies comparing patients with and without vaccination before severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We also included studies reporting symptomatic changes of ongoing long COVID following vaccination among those with a history of SARS-CoV-2 infection. Odds ratios (ORs) for each outcome were synthesized using a random-effects model. Symptomatic changes after vaccination were synthesized by a one-group meta-analysis.

RESULTS

Six observational studies involving 536,291 unvaccinated and 84,603 vaccinated (before SARS-CoV-2 infection) patients (mean age, 41.2-66.6; female, 9.0-67.3%) and six observational studies involving 8,199 long COVID patients (mean age, 40.0 to 53.5; female, 22.2-85.9%) who received vaccination after SARS-CoV-2 infection were included. Two-dose vaccination was associated with a lower risk of long COVID compared to no vaccination (OR, 0.64; 95% confidence interval [CI], 0.45-0.92) and one-dose vaccination (OR, 0.60; 95% CI, 0.43-0.83). Two-dose vaccination compared to no vaccination was associated with a lower risk of persistent fatigue (OR, 0.62; 95% CI, 0.41-0.93) and pulmonary disorder (OR, 0.50; 95% CI, 0.47-0.52). Among those with ongoing long COVID symptoms, 54.4% (95% CI, 34.3-73.1%) did not report symptomatic changes following vaccination, while 20.3% (95% CI, 8.1-42.4%) experienced symptomatic improvement after two weeks to six months of COVID-19 vaccination.

CONCLUSIONS

COVID-19 vaccination before SARS-CoV-2 infection was associated with a lower risk of long COVID, while most of those with ongoing long COVID did not experience symptomatic changes following vaccination.

Long-term systemic and mucosal SARS-CoV-2 IgA response and its association with persistent smell and taste disorders

Introduction

Current approved COVID-19 vaccines, notably mRNA and adenoviral vectored technologies, still fail to fully protect against infection and transmission of various SARS-CoV-2 variants. The mucosal immunity at the upper respiratory tract represents the first line of defense against respiratory viruses such as SARS-CoV-2 and is thus critical to develop vaccine blocking human-to-human transmission.

Methods

We measured systemic and mucosal Immunoglobulin A (IgA) response in serum and saliva from 133 healthcare workers from Percy teaching military hospital following a mild infection (SARS-CoV-2 Wuhan strain, n=58) or not infected (n=75), and after SARS-CoV-2 vaccination (Vaxzevria®/Astrazeneca and/or Comirnaty®/Pfizer).

Results

While serum anti-SARS-CoV-2 Spike IgA response lasted up to 16 months post-infection, IgA response in saliva had mostly fallen to baseline level at 6 months post-infection. Vaccination could reactivate the mucosal response generated by prior infection, but failed to induce a significant mucosal IgA response by itself. Early post-COVID-19 serum anti-Spike-NTD IgA titer correlated with seroneutralization titers. Interestingly, its saliva counterpart positively correlated with persistent smell and taste disorders more than one year after mild COVID-19.

Discussion

As breakthrough infections have been correlated with IgA levels, other vaccine platforms inducing a better mucosal immunity are needed to control COVID-19 infection in the future. Our results encourage further studies to explore the prognosis potential of anti-Spike-NTD IgA in saliva at predicting persistent smell and taste disorders.

Effect of covid-19 vaccination on long covid: systematic review

OBJECTIVE

To determine the effect of covid-19 vaccination, given before and after acute infection with the SARS-CoV-2 virus, or after a diagnosis of long covid, on the rates and symptoms of long covid.

DESIGN

Systematic review.

DATA SOURCES

PubMed, Embase, and Cochrane covid-19 trials, and Europe PubMed Central (Europe PMC) for preprints, from 1 January 2020 to 3 August 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Trials, cohort studies, and case-control studies reporting on patients with long covid and symptoms of long covid, with vaccination before and after infection with the SARS-CoV-2 virus, or after a diagnosis of long covid. Risk of bias was assessed with the ROBINS-I tool.

RESULTS

1645 articles were screened but no randomised controlled trials were found. 16 observational studies from five countries (USA, UK, France, Italy, and the Netherlands) were identified that reported on 614 392 patients. The most common symptoms of long covid that were studied were fatigue, cough, loss of sense of smell, shortness of breath, loss of taste, headache, muscle ache, difficulty sleeping, difficulty concentrating, worry or anxiety, and memory loss or confusion. 12 studies reported data on vaccination before infection with the SARS-CoV-2 virus, and 10 showed a significant reduction in the incidence of long covid: the odds ratio of developing long covid with one dose of vaccine ranged from 0.22 to 1.03; with two doses, odds ratios were 0.25-1; with three doses, 0.16; and with any dose, 0.48-1.01. Five studies reported on vaccination after infection, with odds ratios of 0.38-0.91. The high heterogeneity between studies precluded any meaningful meta-analysis. The studies failed to adjust for potential confounders, such as other protective behaviours and missing data, thus increasing the risk of bias and decreasing the certainty of evidence to low.

CONCLUSIONS

Current studies suggest that covid-19 vaccines might have protective and therapeutic effects on long covid. More robust comparative observational studies and trials are needed, however, to clearly determine the effectiveness of vaccines in preventing and treating long covid.

PROTOCOL REGISTRATION

Open Science Framework https://osf.io/e8jdy.

Effect of Vaccination against SARS-CoV-2 on Long COVID-19: A Narrative Review

Vaccines against SARS-CoV-2 have saved millions of lives and played an important role in containing the COVID-19 pandemic. Vaccination against SARS-CoV-2 is also associated with reduced disease severity and, perhaps, with COVID-19 symptom burden. In this narrative review, we present, in a clinically relevant question-and-answer manner, the evidence regarding the association between vaccination against SARS-CoV-2 and long COVID-19. We discuss how the mechanism of action of vaccines could interplay with the pathophysiology of post-COVID-19 condition. Furthermore, we describe how specific factors, such as the number of vaccine doses and the type of SARS-CoV-2 variants, may affect post-COVID-19 condition. We also discuss the role of timing for vaccination in relation to the onset of long COVID-19 symptoms, as it seems to affect the frequency and severity of the condition. Additionally, we describe the potential modifying effect of age, as well as the association of type and level of immune response with long COVID-19. We also describe how system-specific long COVID-19 sequelae, namely neurocognitive-psychologic symptoms and cardiovascular pathology, could be altered by vaccination. Last, we address the question of whether seasonal influenza vaccination has a meaningful impact on the frequency of long COVID-19.

Comparison of Long COVID-19 Caused by Different SARS-CoV-2 Strains: A Systematic Review and Meta-Analysis

Although many studies of long COVID-19 were reported, there was a lack of systematic research which assessed the differences of long COVID-19 in regard to what unique SARS-CoV-2 strains caused it. As such, this systematic review and meta-analysis aims to evaluate the characteristics of long COVID-19 that is caused by different SARS-CoV-2 strains. We systematically searched the PubMed, EMBASE, and ScienceDirect databases in order to find cohort studies of long COVID-19 as defined by the WHO (Geneva, Switzerland). The main outcomes were in determining the percentages of long COVID-19 among patients who were infected with different SARS-CoV-2 strains. Further, this study was registered in PROSPERO (CRD42022339964). A total of 51 studies with 33,573 patients was included, of which three studies possessed the Alpha and Delta variants, and five studies possessed the Omicron variant. The highest pooled estimate of long COVID-19 was found in the CT abnormalities (60.5%; 95% CI: 40.4%, 80.6%) for the wild-type strain; fatigue (66.1%; 95% CI: 42.2%, 89.9%) for the Alpha variant; and ≥1 general symptoms (28.4%; 95% CI: 7.9%, 49.0%) for the Omicron variant. The pooled estimates of ≥1 general symptoms (65.8%; 95% CI: 47.7%, 83.9%) and fatigue were the highest symptoms found among patients infected with the Alpha variant, followed by the wild-type strain, and then the Omicron variant. The pooled estimate of myalgia was highest among patients infected with the Omicron variant (11.7%; 95%: 8.3%, 15.1%), compared with those infected with the wild-type strain (9.4%; 95%: 6.3%, 12.5%). The pooled estimate of sleep difficulty was lowest among the patients infected with the Delta variant (2.5%; 95%: 0.2%, 4.9%) when compared with those infected with the wild-type strain (24.5%; 95%: 17.5%, 31.5%) and the Omicron variant (18.7%; 95%: 1.0%, 36.5%). The findings of this study suggest that there is no significant difference between long COVID-19 that has been caused by different strains, except in certain general symptoms (i.e., in the Alpha or Omicron variant) and in sleep difficulty (i.e., the wild-type strain). In the context of the ongoing COVID-19 pandemic and its emerging variants, directing more attention to long COVID-19 that is caused by unique strains, as well as implementing targeted intervention measures to address it are vital.

Long-term dyspnea, regional ventilation distribution and peripheral lung function in COVID-19 survivors: a 1 year follow up study

Background

Dyspnea is common after COVID-19 pneumonia and can be characterized by a defective CO2 diffusion (DLCO) despite normal pulmonary function tests (PFT). Nevertheless, DLCO impairment tends to normalize at 1 year, with no dyspnea regression. The altered regional distribution of ventilation and a dysfunction of the peripheral lung may characterize dyspnea at 1 year after COVID-19 pneumonia. We aimed at assessing the pattern of airway resistance and inflammation and the regional ventilation inhomogeneity in COVID-19 pneumonia survivors at 12-months after hospital discharge.

Methods

We followed up at 1-year patients previously admitted to the respiratory units (intensive care or sub-intensive care unit) for COVID-19 acute respiratory failure at 1-year after hospital discharge. PFT (spirometry, DLCO), impulse oscillometry (IOS), measurements of the exhaled nitric oxide (FENO) and Electrical Impedance Tomography (EIT) were used to evaluate lung volumes, CO2 diffusion capacity, peripheral lung inflammation/resistances and the regional inhomogeneity of ventilation distribution. A full medical examination was conducted, and symptoms of new onset (not present before COVID-19) were recorded. Patients were therefore divided into two groups based on the presence/absence of dyspnea (defined as mMRC ≥1) compared to evaluate differences in the respiratory function derived parameters.

Results

Sixty-seven patients were admitted between October and December 2020. Of them, 42/67 (63%) patients were discharged alive and 33 were evaluated during the follow up. Their mean age was 64 ± 11 years and 24/33 (73%) were males. Their maximum respiratory support was in 7/33 (21%) oxygen, in 4/33 (12%) HFNC, in 14/33 (42%) NIV/CPAP and in 8/33 (24%) invasive mechanical ventilation. During the clinical examination, 15/33 (45%) reported dyspnea. When comparing the two groups, no significant differences were found in PFT, in the peripheral airway inflammation (FENO) or mechanical properties (IOS). However, EIT showed a significantly higher regional inhomogeneity in patients with dyspnea both during resting breathing (0.98[0.96–1] vs 1.1[1–1.1], p = 0.012) and during forced expiration (0.96[0.94–1] vs 1 [0.98–1.1], p = 0.045).

Conclusions

New onset dyspnea characterizes 45% of patients 1 year after COVID-19 pneumonia. In these patients, despite pulmonary function test may be normal, EIT shows a higher regional inhomogeneity both during quiet and forced breathing which may contribute to dyspnea.

Clinical trial registration

Clinicaltrials.gov NCT04343053, registration date 13/04/2020.

Impact of COVID-19 vaccination on the risk of developing long-COVID and on existing long-COVID symptoms: A systematic review

Background

Although COVID-19 vaccination decreases the risk of severe illness, it is unclear whether vaccine administration may impact the prevalence of long-COVID. The aim of this systematic review is to investigate the association between COVID-19 vaccination and long-COVID symptomatology.

Methods

MEDLINE, CINAHL, PubMed, EMBASE, and Web of Science databases, as well as medRxiv and bioRxiv preprint servers were searched up to June 20, 2022. Peer-reviewed studies or preprints monitoring multiple symptoms appearing after acute SARS-CoV-2 infection either before or after COVID-19 vaccination collected by personal, telephone or electronic interviews were included. The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale.

Findings

From 2584 studies identified, 11 peer-reviewed studies and six preprints were included. The methodological quality of 82% (n=14/17) studies was high. Six studies (n=17,256,654 individuals) investigated the impact of vaccines before acute SARS-CoV-2 infection (vaccine-infection-long-COVID design). Overall, vaccination was associated with reduced risks or odds of long-COVID, with preliminary evidence suggesting that two doses are more effective than one dose. Eleven studies (n=36,736 COVID-19 survivors) investigated changes in long-COVID symptoms after vaccination (infection-long-COVID-vaccine design). Seven articles showed an improvement in long-COVID symptoms at least one dose post-vaccination, while four studies reported no change or worsening in long-COVID symptoms after vaccination.

Interpretation

Low level of evidence (grade III, case-controls, cohort studies) suggests that vaccination before SARS-CoV-2 infection could reduce the risk of subsequent long-COVID. The impact of vaccination in people with existing long-COVID symptoms is still controversial, with some data showing changes in symptoms and others did not. These assumptions are limited to those vaccines used in the studies.

Funding

The LONG-COVID-EXP-CM study supported by a grant of Comunidad de Madrid.

Effect of COVID-19 Vaccines on Reducing the Risk of Long COVID in the Real World: A Systematic Review and Meta-Analysis

The coronavirus disease 2019 (COVID-19) is still in a global pandemic state. Some studies have reported that COVID-19 vaccines had a protective effect against long COVID. However, the conclusions of the studies on the effect of COVID-19 vaccines on long COVID were not consistent. This study aimed to systematically review relevant studies in the real world, and performed a meta-analysis to explore the relationship between vaccination and long COVID. We systematically searched PubMed, Embase, Web of science, and ScienceDirect from inception to 19 September 2022. The PICO (P: patients; I: intervention; C: comparison; O: outcome) was as follows: patients diagnosed with COVID-19 (P); vaccination with COVID-19 vaccines (I); the patients were divided into vaccinated and unvaccinated groups (C); the outcomes were the occurrence of long COVID, as well as the various symptoms of long COVID (O). A fixed-effect model and random-effects model were chosen based on the heterogeneity between studies in order to pool the effect value. The results showed that the vaccinated group had a 29% lower risk of developing long COVID compared with the unvaccinated group (RR = 0.71, 95% CI: 0.58-0.87, p < 0.01). Compared with patients who were not vaccinated, vaccination showed its protective effect in patients vaccinated with two doses (RR = 0.83, 95% CI: 0.74-0.94, p < 0.01), but not one dose (RR = 0.83, 95% CI: 0.65-1.07, p = 0.14). In addition, vaccination was effective against long COVD in patients either vaccinated before SARS-CoV-2 infection/COVID-19 (RR = 0.82, 95% CI: 0.74-0.91, p < 0.01) or vaccinated after SARS-CoV-2 infection/COVID-19 (RR = 0.83, 95% CI: 0.74-0.92, p < 0.01). For long COVID symptoms, vaccination reduced the risk of cognitive dysfunction/symptoms, kidney diseases/problems, myalgia, and sleeping disorders/problems sleeping. Our study shows that COVID-19 vaccines had an effect on reducing the risk of long COVID in patients vaccinated before or after SARS-CoV-2 infection/COVID-19. We suggest that the vaccination rate should be improved as soon as possible, especially for a complete vaccination course. There should be more studies to explore the basic mechanisms of the protective effect of COVID-19 vaccines on long COVID in the future.

[The value of COVID-19 vaccination in the context of Long-COVID]

There are currently no strategies available on how to deal with Long-COVID (COVID "coronavirus disease"). COVID-19 vaccination could be both a preemptive and a therapeutic option for the future. The evaluation of the available studies is complicated by varying definitions. There are, however, indications that (complete) COVID-19 vaccination is able not only to prevent symptomatic infection but also to reduce the risk of Long-COVID. In some patients with Long-COVID, symptoms are modified after (first and/or second) COVID-19 vaccination; however, there is no clear evidence for a real therapeutic effect on Long-COVID.

COVID-19 Vaccine and Long COVID: A Scoping Review

As the COVID-19 pandemic progresses, changing definitions and therapeutics regarding the post-acute sequela of COVID-19, particularly long COVID, have become a subject of great interest and study. The study aims to describe the pathophysiology and discuss different therapeutic agents currently available for long COVID. Another objective is to assess comparative efficacy between different types of vaccines on symptoms of long COVID. A preliminary search was conducted using Ovid Medline, Embase, medRxiv, and NIH COVID-19 portfolios. A total of 16 studies were included in our review. Despite some of the data showing variable results, most of the vaccinated patients reported improvement in long COVID symptoms with no significant difference between various types of vaccines. Further trials are needed to better identify the comparative efficacy of vaccines for long COVID and ascertain other therapeutic modalities.