Examining the Intersection of Inflammatory Bowel Disease and COVID-19: Insights from a National Inpatient Database Study (preprint)

Background: This study aimed to investigate the clinical indicators and outcomes of COVID-19-positive patients with inflammatory bowel disease (IBD), focusing on age, sex, socioeconomic status, and geographic location. The objective of this study was to fill the knowledge gap regarding determinants influencing outcomes in individuals with and without IBD who contracted COVID-19, thus impacting healthcare provision.Methods: This study utilized the nationwide inpatient sample (NIS) database for the period from January to December 2020. Patients were categorized into those with COVID-19 alone (controls) and those with both COVID-19 and IBD (cases). Demographic, clinical, and hospital-related variables were analyzed using statistical methods, including t tests and chi-square tests. Logistic and multivariate regression analyses were performed to assess factors affecting mortality.Results: Among COVID-19 patients with IBD, a sex disparity was observed, with more females in the IBD group than in the non-IBD group. The mean age was similar in both groups. Hospitalizations were concentrated in the age group of 65–84 years. Ethnically, Caucasians dominated both cohorts, and Medicare was the primary payer for a greater proportion of hospitalizations in the IBD group. Hospitalizations were prevalent in urban teaching hospitals, primarily in the southern and mid-western regions of the US. There were no significant differences in mortality rates, and clinical symptoms were comparable between the two groups. Factors associated with mortality included sex, age, and specific existing health conditions.Conclusion: Contrary to the initial hypothesis, the presence of IBD among COVID-19 patients did not significantly impact mortality rates. However, certain clinical indicators and outcomes are influenced by individual factors such as age, sex, and underlying health conditions. This study emphasizes the need for careful monitoring of COVID-19 patients with IBD, particularly those with additional risk factors. Further research is necessary to fully understand the biochemical interactions and implications of IBD in the context of COVID-19. This comprehensive study contributes valuable insights to healthcare authorities, aiding in patient management and outcome optimization.

Sentiment Analysis and Text Analysis of the Public Discourse on Twitter about COVID-19 and MPox (preprint)

Mining and analysis of the big data of Twitter conversations have been of significant interest to the scientific community in the fields of healthcare, epidemiology, big data, data science, computer science, and their related areas, as can be seen from several works in the last few years that focused on sentiment analysis and other forms of text analysis of tweets related to Ebola, E-Coli, Dengue, Human Papillomavirus, Middle East Respiratory Syndrome, Measles, Zika virus, H1N1, influenza like illness, swine flu, flu, Cholera, Listeriosis, cancer, Liver Disease, Inflammatory Bowel Disease, kidney disease, lupus, Parkinsons, Diphtheria, and West Nile virus. The recent outbreaks of COVID-19 and MPox have served as catalysts for Twitter usage related to seeking and sharing information, views, opinions, and sentiments involving both of these viruses. None of the prior works in this field analyzed tweets focusing on both COVID-19 and MPox simultaneously. To address this research gap, a total of 61,862 tweets that focused on MPox and COVID-19 simultaneously, posted between 7 May 2022 and 3 March 2023, were studied. The findings and contributions of this study are manifold. First, the results of sentiment analysis using the VADER approach show that nearly half the tweets had a negative sentiment. It was followed by tweets that had a positive sentiment and tweets that had a neutral sentiment, respectively. Second, this paper presents the top 50 hashtags used in these tweets. Third, it presents the top 100 most frequently used words in these tweets after performing tokenization, removal of stopwords, and word frequency analysis. Finally, a comprehensive comparative study that compares the contributions of this paper with 49 prior works in this field is presented to further uphold the relevance and novelty of this work.

IFIH1 loss-of-function predisposes to inflammatory and SARS-CoV-2-related infectious diseases (preprint)

The IFIH1 gene, encoding melanoma differentiation-associated protein 5 (MDA5), is an indispensable innate immune regulator involved in the early detection of viral infections. Previous studies described MDA5 dysregulation linking it to weakened immunological responses, and increased susceptibility to microbial infections and autoimmune disorders. Monoallelic gain-of-function of the IFIH1 gene has been associated with multisystem disorders, namely Aicardi-Goutieres and Singleton-Merten syndromes, while biallelic loss of this gene causes immunodeficiency. In this study, nine patients suffering from different cases of recurrent infections, inflammatory diseases, severe COVID-19, or multisystem inflammatory syndrome in children (MIS-C) were identified with putative loss-of-function IFIH1 variants by whole exome sequencing. All patients revealed signs of lymphopenia and an increase in inflammatory markers, including CRP, amyloid A, ferritin, and IL-6. One patient with a pathogenic homozygous variant c.2807+1G>A was the most severe case showing immunodeficiency and glomerulonephritis. The c.1641+1G>C variant was identified in the heterozygous state in patients suffering from periodic fever, COVID-19, or MIS-C, while the c.2016delA variant was identified in two patients with inflammatory bowel disease or MIS-C. Expression analysis showed that PBMCs of one patient with a c.2016delA variant had a significant decrease in ISG15, IFNA and IFNG transcript levels, compared to normal PBMCs, upon stimulation with poly(I:C), suggesting that MDA5 receptor truncation disrupts the immune response. Our findings accentuate the implication of rare monogenic IFIH1 loss-of-function variants in altering the immune response, and severely predisposing patients to inflammatory and infectious diseases, including SARS-CoV-2 related disorders.

COVID-19 Impact in Crohn Disease Patients Underwent Autologous Hematopoietic Stem Cell Transplantation (preprint)

SARS COV 2 is the virus responsible for COVID-19, a disease that has been blamed for inducing or exacerbating symptoms in patients with autoimmune diseases. Crohn's disease (CD) is an inflammatory bowel disease that affects genetically susceptible patients who develop an abnormal mucosal immune response to the intestinal microbiota. Patients who underwent Hematopoietic Stem cell Transplantation are considered at risk for COVID-19. The objective of this report was to describe for the first time the impact of COVID-19 in a group of 50 patients with Crohn's Disease (CD, 28 females, and 22 male) with a mean age of 38 years, previously submitted to Autologous, non-myeloablative, Hematopoietic Stem Cell Transplantation (Auto HSCT) between 2013 and 2021. In this series, 19 patients were diagnosed with positive COVID-19. In two (2) patients there was a report of the occurrence of two infectious episodes. Parameters related to HSCT, such as time elapsed since the procedure, vaccination status, CD status before and after infection, and clinical manifestations resulting from COVID-19, were evaluated. Among the patients with COVID-19, in three, submitted to Auto HSCT less than six (6) months ago, there was a change in the CD status, and one of them, in addition to the CD symptoms, started to present thyroid impairment with positive anti-TPO. Only one of the patients required hospitalization for five days to treat COVID-19 and remained in CD clinical remission. Nine patients reported late symptoms that may be related to COVID-19. There were no deaths, and the statistical evaluation of the series of COVID-19 patients after HSCT and those who did not present an infectious episode did not present significant data regarding the analyzed parameters. Despite the change in CD status in three patients and the presence of nine patients with late symptoms, we can conclude that there was no significant adverse impact concerning COVID-19 in the evaluated patients who underwent HSCT to treat CD. Key Words: Inflammatory bowel disease, Crohn Disease, SARs COV 2, COVID - 19, Autologous Hematopoietic Stem Cell Transplantation, Stem Cell Therapy.

Lower-dose Intravenous Immunoglobulin Therapy for Geriatric Inflammatory Bowel Disease Accompanied by COVID-19 Multisystem Inflammatory Syndrome: a Case Report (preprint)

Background this article presents a noteworthy case of SARS-CoV-2-associated inflammatory bowel disease (IBD) in an elderly individual who endured three hospitalizations without favorable response to conventional treatment. Ultimately, the patient's symptoms subsided following the administration of intravenous immunoglobulin (IVIg).Case presentation : the patient, an elderly individual, experienced short-term fever and sore throat after encountering the COVID-19 pandemic. Despite receiving a three-dose inactivated COVID-19 vaccine, the patient tested positive for SARS-CoV-2 antigen and developed worsening symptoms, including diarrhea and recurrent fever. Initial antibiotic treatment for bacterial enteritis proved ineffective. Further evaluation, including endoscopy and pathology, confirmed the diagnosis of IBD with concurrent multisystem inflammatory syndrome (MIS) in adults. Following lower-dose IVIg administration, the patient's symptoms improved, with resolution of fever, diarrhea, and inflammation.Conclusions the case highlights the complexity of diagnosis and treatment in geriatric with IBD and MIS, emphasizing the importance of early intervention with IVIg. Further research is needed to explore the relationship between COVID-19 infection, MIS, and acute autoimmune diseases, as well as the efficacy of IVIg in these conditions.

EVOLUTION OF DIAGNOSTIC DELAY IN PEDIATRIC INFLAMMATORY BOWEL DISEASE AND THE IMPACT OF THE COVID-19 PANDEMIC.

BACKGROUND: Pediatric inflammatory bowel disease (IBD) is increasingly prevalent, but diagnosis can still be challenging. Diagnostic delay is particularly deleterious in this age group. OBJECTIVE: This study explores the evolution of diagnostic delay in pediatric IBD and the influence of the COVID-19 pandemic. METHODS: Retrospective study including all pediatric IBD patients diagnosed during 2014, 2019 and 2020 in a tertiary hospital. Diagnostic delay, time to first medical visit, time to pediatric gastroenterologist (PG) visit and time to diagnosis were calculated and compared within a gap of five years (2019 and 2014) and with the year of onset of the pandemic (2020 and 2019). RESULTS: A total of 93 participants were included (2014: 32, 2019: 30, 2020: 31). No significant differences were observed in diagnostic delay, time to first medical visit in Crohn's disease (CD), time to PG visit and time to diagnosis when comparing 2019-2014 and 2020-2019. Time to first visit in ulcerative colitis (UC) and Undetermined-IBD increased in 2019 (P=0.03), with new decrease in 2020 (P=0.04). Diagnostic delay was longer in DC compared to UC plus Undetermined-IBD. CONCLUSION: Diagnostic delay is still an important matter in pediatric IBD, with no significant change over the last years. The time to the first PG visit and the time for diagnosis seem to have the greatest impact on diagnostic delay. Thus, strategies to enhance recognition of IBD symptoms among first-line physicians and to improve communication, facilitating referral, are of utmost importance. Despite the restraints in the health care system caused by the pandemic, time to diagnosis in pediatric IBD was not impaired during 2020 in our center.

Anti-tumor necrosis factor therapy is associated with attenuated humoral response to SARS-COV-2 vaccines in patients with inflammatory bowel disease.

BACKGROUND: Immunosuppressive therapy used in the treatment of inflammatory bowel disease (IBD) is known to reduce vaccine immunogenicity. AIMS: This study aimed to 1) predict the humoral response elicited by SARS-CoV-2 vaccination in IBD patients based on their ongoing treatment and other relevant patient and vaccine characteristics and 2) assess the humoral response to a booster dose of mRNA vaccine. METHODS: We conducted a prospective study in adult IBD patients. Anti-spike (S) IgG antibodies were measured after initial vaccination and again after one booster dose. A multiple linear regression model was created to predict anti-S antibody titer following initial complete vaccination in different therapeutic groups (no immunosuppression, anti-TNF, immunomodulators and combination therapy). A two-tailed Wilcoxon test for two dependent groups was performed to compare anti-S values before and after the booster dose. RESULTS: Our study included 198 IBD patients. The multiple linear regression identified anti-TNF and combination therapy (versus no immunosuppression), current smoking, viral vector (versus mRNA) vaccine and interval between vaccination and anti-S measurement as statistically significant predictors of the log anti-S antibody levels (p < 0.001). No statistically significant differences were found between no immunosuppression and immunomodulators (p = 0.349) and between anti-TNF and combination therapy (p = 0.997). Statistically significant differences for anti-S antibody titer before and after the booster dose of mRNA SARS-CoV-2 vaccine were found, both for non-anti-TNF and anti-TNF groups. CONCLUSIONS: Anti-TNF treatment (either alone or in combination therapy) is associated with lower anti-S antibody levels. Booster mRNA doses seem to increase anti-S both in non-anti-TNF and anti-TNF treated patients. Special attention should be paid to this group of patients when planning vaccination schemes.

Real-world efficacy and safety of vedolizumab in managing ulcerative colitis versus Crohn's disease: results from an Italian multicenter study.

BACKGROUND: Vedolizumab (VDZ) can be used to treat refractory ulcerative colitis (UC) and Crohn's disease (CD). We assessed whether there are differences in treating UC vs CD with VDZ. RESEARCH DESIGN AND METHODS: Mayo score in UC and the Harvey-Bradshaw Index (HBI) in CD scored the clinical activity. Achievement and maintenance of clinical remission during the follow-up, and safety were the primary endpoints. RESULTS: 729 patients (475 with UC and 254 with CD), median follow-up of 18 (IQR 6-36) months, were enrolled. Clinical remission at the 6th month of treatment was achieved in 488 (66.9%) patients (74.4% in CD vs 62.9% in UC, p<0.002) while, during the follow-up, no difference was found (81.5% in the UC group and 81.5% pts in the CD group; p=0.537). The clinical remission at the 6th month of treatment (p=0.001) and being naïve to biologics (p<0.0001) were significantly associated with prolonged clinical remission. The clinical response was significantly higher in UC (90.1%) vs CD (84.3%) (p=0.023), and surgery occurred more frequently in CD (1.9% in UC vs 5.1% in CD, p=0.016). CONCLUSION: We found differences when using VDZ in UC vs CD in real life. These parameters can help the physician predict this drug's longterm efficacy.

Seroprevalence of ANTI-SARS-CoV-2 antibodies in patients with inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) treated with biologic and/or immunosuppressant drugs are at increased risk for opportunistic infections. Seroprevalence studies can confirm the diagnosis of SARS-CoV-2 infections as well as the associated risk factors. This is a descriptive study which primary endpoints were to highlight the prevalence of SARS-CoV-2 antibodies in a cohort of IBD patients in March 2021, and to analyze seroconversion in patients with known COVID-19 infection and its relationship with IBD treatments. Patients filled in a questionnaire about symptoms of COVID-19 infection and clinical information about their IBD. All included patients were tested for SARS-CoV-2 antibodies. 392 patients were included. Among patients with clinical infection, 69 patients (17,65%) were IgG-positive, 286 (73,15%) IgG-negative and 36 (9,21%) indeterminate. In relation to seroconversion among patients under biologic treatment, 13 patients of the 23 with a previous positive CRP developed antibodies (56.5%). However, when the influence of immunosuppressive treatment on the probability of developing antibodies was analyzed, no significant differences were seen between those patients with or without treatment (77.8% vs. 77.1%, p = 0.96). In our cohort of IBD patients, after one year of pandemic, there were 18.64% IgG positive patients, a higher prevalence than the general population (15.7%).

Adverse Events Related to SARS-CoV-2 Vaccine in a Nationwide Cohort of Patients With Inflammatory Bowel Disease.

INTRODUCTION: There are limited data on the safety profile of the severe acute respiratory syndrome coronavirus-2 vaccine among patients taking immunosuppressive medications. Our aim was to evaluate the adverse events related to the vaccines in a nationwide cohort of patients with inflammatory bowel disease on diverse immunosuppressive medications. METHODS: This was a retrospective cohort study using data from the Veterans Health Administration. The primary outcome was any adverse event of special interest (cerebrovascular accident, venous thromboembolism, acute myocardial infarction, Bell palsy) within 90 days of vaccination. RESULTS: A total of 17,201 patients were included, and 12,351 patients (71.8%) received at least 1 vaccine dose. The most common adverse events were acute myocardial infarction and venous thromboembolism. In inverse probability treatment weighting-adjusted logistic regression, full vaccination was not significantly associated with increased adverse events through 90 days, relative to unvaccinated patients. DISCUSSION: Full severe acute respiratory syndrome coronavirus-2 vaccination was not associated with an increased rate of key adverse events relative to unvaccinated individuals among patients with inflammatory bowel disease.

Two Case Reports of Newly Diagnosed Crohn's Disease after COVID-19 in Pediatric Patients.

Since the coronavirus disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome-coronavirus-2 virus (SARS-CoV-2), various complications have been reported. Although most COVID-19 cases exhibited flu-like symptoms, COVID-19 may dysregulate the immune response and promote overwhelming levels of inflammation in some patients. Inflammatory bowel disease (IBD) is caused by dysregulated or inappropriate immune responses to environmental factors in a genetically susceptible host, and a SARS-CoV-2 infection may act as a possible cause of IBD. This paper describes two pediatric patients who developed Crohn's disease following a SARS-CoV-2 infection. They were previously healthy before the SARS-CoV-2 infection. On the other hand, they started to develop fever and gastrointestinal symptoms several weeks after recovery from the infection. They were diagnosed with Crohn's disease by imaging and endoscopic studies, and their symptoms improved after treatment with steroids and azathioprine. This paper suggests that a SARS-CoV-2 infection may trigger IBD in predisposed patients.

Multiple infliximab biosimilar switches appear to be safe and effective in a real-world inflammatory bowel disease cohort.

BACKGROUND: Switching from originator infliximab (IFX) to biosimilar IFX is effective and safe. However, data on multiple switching are scarce. The Edinburgh inflammatory bowel disease (IBD) unit has undertaken three switch programmes: (1) Remicade to CT-P13 (2016), (2) CT-P13 to SB2 (2020), and (3) SB2 to CT-P13 (2021). OBJECTIVE: The primary endpoint of this study was to assess CT-P13 persistence following switch from SB2. Secondary endpoints included persistence stratified by the number of biosimilar switches (single, double and triple), effectiveness and safety. METHODS: We performed a prospective, observational, cohort study. All adult IBD patients on IFX biosimilar SB2 underwent an elective switch to CT-P13. Patients were reviewed in a virtual biologic clinic with protocol driven collection of clinical disease activity, C-reactive protein (CRP), faecal calprotectin (FC), IFX trough/antibody levels, and drug survival. RESULTS: 297 patients (CD n = 196 [66%], ulcerative colitis/inflammatory bowel disease unclassified n = 101, [34%]) were switched (followed-up: 7.5 months [6.8-8.1]). This was the third, second and first IFX switch for 67/297 (22.5%), 138/297 (46.5%) and 92/297 (31%) of the cohort respectively. 90.6% of patients remained on IFX during follow-up. The number of switches was not independently associated with IFX persistence after adjusting for confounders. Clinical (p = 0.77), biochemical (CRP ≤5 mg/ml; p = 0.75) and faecal biomarker (FC<250 µg/g; p = 0.63) remission were comparable at baseline, week 12 and week 24. CONCLUSION: Multiple successive switches from IFX originator to biosimilars are effective and safe in patients with IBD, irrespective of the number of IFX switches.

Association Between Inflammatory Bowel Disease and Viral Infections.

Chronic inflammatory gastrointestinal diseases such as Crohn's disease (CD) and ulcerative colitis (UC) are known as inflammatory bowel disorders (IBD). Patients with inflammatory bowel illnesses are more susceptible to viral infections. In people with IBD, viral infections have emerged as a significant issue. Viral infections are often difficult to identify and have a high morbidity and fatality rate. We reviewed studies on viral infections and IBD, concentrating on Cytomegalovirus (CMV), SARS-CoV-2, Epstein-Barr virus (EBV), enteric viruses, and hepatitis B virus (HBV). Also, the effect of IBD on these viral infections is discussed. These data suggest that patients with IBD are more likely to get viral infections. As a result, practitioners should be aware of the increased risk of viral infections in inflammatory bowel disease patients.

Safety, hesitancy of coronavirus disease 2019 vaccination and pandemic burden in patients with inflammatory bowel disease: data of a national study (ESCAPE-IBD).

BACKGROUND AND AIMS: The purpose of this study was to present data on the safety of anti- severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in a cohort of inflammatory bowel disease (IBD) patients of an ongoing multicenter study (ESCAPE-IBD) sponsored by the Italian Group for the study of Inflammatory Bowel Disease (ClinicalTrials.gov Identifier: NCT04769258). METHODS: Anti-SARS-CoV-2 vaccination was administrated to 809 IBD patients. Interviews were conducted to report adverse events related to vaccination. Of these 809, 346 patients were surveyed on the pandemic burden and the main reason for hesitancy in coronavirus disease 2019 vaccination. The chi-square test was used to compare categorical variables. Logistic regression was used to assess the relationship between disease-related characteristics and the onset of adverse events. RESULTS: About 45% of patients had at least one side effect, following the first dose (10%), the second (15%), and both doses (19%). All the adverse events were mild and lasted only a few days. Logistic regression analysis revealed that female sex ( P  < 0.001), younger age ( P  = 0.001), seroconversion ( P  = 0.002), and comorbidity ( P  < 0.001) were significantly associated with adverse events. The survey showed that the main concerns were the possibility of adverse event (33%). Almost all patients (99%) felt safer having been vaccinated at their IBD reference center. CONCLUSION: The vaccine reactions experienced in IBD patients were mostly self-limited. We found high acceptance and good safety of SARS-CoV-2 vaccination in our cohort.

Comprehensive analysis to identify the influences of SARS-CoV-2 infections to inflammatory bowel disease.

Background: Coronavirus disease 2019 (COVID-19) and inflammatory bowel disease (IBD) are both caused by a disordered immune response and have direct and profound impacts on health care services. In this study, we implemented transcriptomic and single-cell analysis to detect common molecular and cellular intersections between COVID-19 and IBD that help understand the linkage of COVID-19 to the IBD patients. Methods: Four RNA-sequencing datasets (GSE147507, GSE126124, GSE9686 and GSE36807) from Gene Expression Omnibus (GEO) database are extracted to detect mutual differentially expressed genes (DEGs) for IBD patients with the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to find shared pathways, candidate drugs, hub genes and regulatory networks. Two single-cell RNA sequencing (scRNA-eq) datasets (GSE150728, PRJCA003980) are used to analyze the immune characteristics of hub genes and the proportion of immune cell types, so as to find common immune responses between COVID-19 and IBD. Results: A total of 121 common DEGs were identified among four RNA-seq datasets, and were all involved in the functional enrichment analysis related to inflammation and immune response. Transcription factors-DEGs interactions, miRNAs-DEGs coregulatory networks, and protein-drug interactions were identified based on these datasets. Protein-protein interactions (PPIs) was built and 59 hub genes were identified. Moreover, scRNA-seq of peripheral blood monocyte cells (PBMCs) from COVID-19 patients revealed a significant increase in the proportion of CD14+ monocytes, in which 38 of 59 hub genes were highly enriched. These genes, encoding inflammatory cytokines, were also highly expressed in inflammatory macrophages (IMacrophage) of intestinal tissues of IBD patients. Conclusions: We conclude that COVID-19 may promote the progression of IBD through cytokine storms. The candidate drugs and DEGs-regulated networks may suggest effective therapeutic methods for both COVID-19 and IBD.

COVID-19 susceptibility and clinical outcomes in inflammatory bowel disease: An updated systematic review and meta-analysis.

The susceptibility, risk factors, and prognosis of COVID-19 in patients with inflammatory bowel disease (IBD) remain unknown. Thus, our study aims to assess the prevalence and clinical outcomes of COVID-19 in IBD. We searched PubMed, EMBASE, and medRxiv from 2019 to 1 June 2022 for cohort and case-control studies comparing the prevalence and clinical outcomes of COVID-19 in patients with IBD and in the general population. We also compared the outcomes of patients receiving and not receiving 5-aminosalicylates (ASA), tumour necrosis factor antagonists, biologics, systemic corticosteroids, or immunomodulators for IBD. Thirty five studies were eligible for our analysis. Pooled odds ratio of COVID-19-related hospitalisation, intensive care unit (ICU) admission, or death in IBD compared to in non-IBD were 0.58 (95% confidence interval (CI) = 0.28-1.18), 1.09 (95% CI = 0.27-4.47), and 0.67 (95% CI = 0.32-1.42), respectively. Inflammatory bowel disease was not associated with increased hospitalisation, ICU admission, or death. Susceptibility to COVID-19 did not increase with any drugs for IBD. Hospitalisation, ICU admission, and death were more likely with 5-ASA and corticosteroid use. COVID-19-related hospitalisation (Odds Ratio (OR): 0.53; 95% CI = 0.38-0.74) and death (OR: 0.13; 95% CI = 0.13-0.70) were less likely with Crohn's disease than ulcerative colitis (UC). In conclusion, IBD does not increase the mortality and morbidity of COVID-19. However, physicians should be aware that additional monitoring is needed in UC patients or in patients taking 5-ASA or systemic corticosteroids.

COVID-19 Vaccine Effectiveness Against the Omicron Variant in a Veterans Affairs Cohort of Patients With Inflammatory Bowel Disease.

INTRODUCTION: With the advent of the Omicron variant, there are concerns about the efficacy of current vaccinations, especially among immunocompromised/immunosuppressed patients. Our aim was to determine the efficacy of the first booster dose against Omicron. METHODS: This was a retrospective cohort study using a well-established inflammatory bowel disease (IBD) cohort in the Veterans Health Administration. We followed patients on baseline IBD medications through the month of January 2022 during the Omicron COVID-19 wave and created adjusted models for vaccination and boosting effectiveness in reducing SARS-CoV-2 infection, hospitalization, and all-cause mortality. RESULTS: A total of 22,756 patients with IBD were included, of whom 34.9% had received a booster dose. During follow-up, 622 patients (2.7%) were diagnosed with SARS-CoV-2 infection. In adjusted models, booster status was associated with a 30% reduced hazard of SARS-CoV-2 infection (hazard ratio 0.70 vs unvaccinated status, 95% confidence interval 0.56-0.88, P = 0.002), translating to 25.05% effectiveness. Boosted status was also significantly associated with reduced COVID-19 hospitalization (hazard ratio 0.35, 95% confidence interval 0.16-0.74, P = 0.006), demonstrating a 65.06% effectiveness in adjusted models. There was no significant association between vaccination status and all-cause mortality in adjusted models. DISCUSSION: The boosted state was associated with a lower risk of SARS-CoV-2 infections and COVID-19-related hospitalization. Efficacy was lower than what has been seen against previous variants and decreased with prolonged duration from the booster. These findings suggest that patients with IBD, especially those who are immunosuppressed, should consider getting a second booster as per Centers for Disease Control and Prevention recommendations.