Choroiditis following severe acute respiratory syndrome coronavirus 2 infection in unvaccinated identical twins

ABSTRACT Unvaccinated identical twins developed bilateral anterior uveitis soon after the onset of coronavirus disease 2019 symptoms. During follow-up, both patients developed choroiditis, and one twine developed posterior scleritis and serous retinal detachment. Prompt treatment with oral prednisone ameliorated the lesions, and no recurrence was observed at the 18-month follow-up. Choroiditis may rarely be associated with severe acute respiratory syndrome coronavirus 2 infection, and it responds well to corticosteroid therapy. Although the exact mechanism is unknown, we hypothesize that the virus may act as an immunological trigger for choroiditis.

KANET evaluation in patients with SARS-CoV-2.

OBJECTIVES: To determine a possible correlation between SARS-CoV-2 infection during pregnancy and altered fetal behavior. METHODS: Kurjak's antenatal neurodevelopmental test (KANET) was applied from 28 to 40 weeks in 38 gestations (group A) diagnosed with COVID-19 infection during the first week and 43 non-COVID pregnant women (group B). RESULTS: No statistically significant differences considering maternal age (33±3.9 years for group A vs. 31±4.1 years for group B) and gestational age (33±1.6 weeks for group A compared to 33±2.1 weeks for group B) were observed. KANET scores were not different between the two groups. CONCLUSIONS: Fetal behavior differences are not altered in women diagnosed with SARS-CoV-2 infection during the third trimester of pregnancy.

Reversible effects of the SARS-CoV-2 on semen parameters.

Despite that the SARS-CoV-2 pandemic has been controlled, it has affected a large proportion of the population, raising some concerns about potential sequelae in men at reproductive age. To contribute to the clarification of this issue, we performed a retrospective study comparing semen parameters values before and after confirmed SARS-CoV-2 infection in a large cohort of infertile men, compared to a control group that did not undergo SARS-CoV-2 infection. Wilcoxon test on paired samples and general linear regression model showed that SARS-CoV-2 infection has a detrimental effect on semen volume values (p < 0.005). However, semen volume seems to be significantly lower only during the first spermatogenic cycle after SARS-COV-2 infection (p < 0.005) and mainly in unvaccinated patients (p < 0.05). In addition, we detected alterations in progressive motility in patients infected with the alpha SARS-COV-2 strain (p < 0.05). In conclusion, our results show that although SARS-CoV-2 has a small effect on semen volume and sperm motility in infertile men, depending on the infectious strain or vaccination status, pre-infection values of semen parameters appear to be restored over one spermatogenic cycle after infection.

Differential associations between SARS-CoV-2 infection, perceived burden of the pandemic and mental health in the German population-based cohort for digital health research.

Understanding the potential adverse effects of the COVID-19-pandemic on mental health remains a challenge for public health. Differentiation between potential consequences of actual infection with SARS-CoV-2 and the subjective burden of the pandemic due to measures and restrictions to daily life still remains elusive. Therefore, we investigated the differential association between infection with SARS-Cov-2 and subjective burden of the pandemic in a study cohort of 7601 participants from the German population-based cohort for digital health research (DigiHero), who were recruited between March 4th and April 25th 2022. Data was collected using the online survey tool LimeSurvey® between March and October 2022 in consecutive surveys, which included questionnaires on infection status and symptoms following COVID-19 as well as retrospective assessment of the subjective burden of the pandemic. We observed an association of a past SARS-CoV-2 infection on deteriorated mental health related symptoms, whereas no association or interaction with burden of the pandemic occurred. The association was driven by participants with persistent symptoms 12 weeks after infection. On a symptom specific level, neuropsychiatric symptoms such as exhaustion and fatigue, concentration deficits and problems with memory function were the primary drivers of the association with small effect sizes between 0.048 and 0.062 ηp2.

Integrated viral and immune monitoring in a prospective COVID-19 cohort from India.

In this study, we report on longitudinal kinetics of cellular immune subsets following SARS-CoV-2 infection in a cohort of hospitalized individuals and evaluate the interplay of these profiles with infecting viral variants, humoral immunity including neutralizing responses, vaccination history and clinical outcomes. A cohort of 121 SARS-CoV-2 infected individuals exhibiting varying disease states were prospectively evaluated for lymphopenic profiles, anti-viral humoral responses and infecting viral variants for a period of up to 90 days spanning the period, February 2021-January 2022 (2nd and 3rd waves of infection). A total of 51 participants received at least one vaccine dose of indigenous vaccines (Covishield or Covaxin) prior to recruitment. When stratified in terms of mortality, B and NK cells, in contrast to the T cell compartment, did not recover from nadir levels in non-survivors who were largely unvaccinated. No discriminatory signature was identified for non-survivors in terms of anti-NC or anti-S1-RBD IgG CLIA profiles including GenScript S1-RBD assays. Evaluation of sVCAM and sMAdCAM revealed opposing dynamics that correlated with disease severity and convalescence respectively. Viral variant analysis revealed delta and omicron variants to comprise majority of the infections which reflected national transmission kinetics during the period of recruitment. Our results demonstrate the importance of monitoring circulating biomarkers for convalescence as well as mortality in COVID-19 progression. Delta variants of SARS-CoV-2 clearly demonstrated increased pathogenicity and warrants sustained viral surveillance for re-emergence of these strains. Our findings with respect to vaccination advocate for continued vaccine development and administration of COVID-19 vaccines.

Humoral immune response as an indicator for protection against Covid-19 after anti-SARS-COV2-booster vaccination in hematological and oncological patients.

Cancer patients are at a higher risk to develop severe COVID-19 symptoms after SARS-CoV-2 infection compared to the general population and regularly show an impaired immune response to SARS-CoV-2 vaccination. In our oncological center, 357 patients with hematological and oncological diseases were monitored for neutralizing antibodies from October 2021 over 12 months. All patients had received three anti-SARS-CoV-2 vaccinations with an mRNA-(Comirnaty/BionTech or Spikevax/Moderna) or a vector vaccine (Vakzevria/AstraZeneca or JCOVDEN/Johnson&Johnson). Neutralizing anti-SARS-CoV-2 IgG antibodies in the patients' sera were detected within 3 months before, 3-10 weeks and 5-7 months after the booster vaccination (third vaccination). 112 patients developed a breakthrough SARS-CoV-2 infection during the observation period. High anti-SARS-Cov-2 antibody levels before infection significantly protected against symptomatic Covid-19 disease (p = .003). The median antibody titer in patients with asymptomatic Covid-19 disease was 2080 BAU/ml (binding antibody units per Milliliter) and 765 BAU/ml in symptomatic patients. 98% of the solid tumor patients reached seroconversion after the booster vaccination in comparison to 79% of the hematological patients. High antibody titers of >2080 BAU/ml after the booster vaccination were detected in 61% of the oncological and 34.8% of the hematological patients. 7-10 months after the booster vaccination, the anti-SARS-CoV-2 antibody titer declined to an average of 849 BAU/ml. Considering the heterogenous humoral immune response of cancer patients observed in this study, an individual vaccination strategy based on regular measurement of anti-SARS-CoV-2 antibody levels should be considered in contrast to fixed vaccination intervals.

Discovery of the potent covalent inhibitor with an acrylate warhead for SARS-CoV-2 3CL protease.

COVID-19 has caused severe consequences in terms of public health and economy worldwide since its outbreak in December 2019. SARS-CoV-2 3C-like protease (3CLpro), crucial for the viral replications, is an attractive target for the development of antiviral drugs. In this study, several kinds of Michael acceptor warheads were utilized to hunt for potent covalent inhibitors against 3CLpro. Meanwhile, novel 3CLpro inhibitors with the P3-3,5-dichloro-4-(2-(dimethylamino)ethoxy)phenyl moiety were designed and synthesized which may form salt bridge with residue Glu166. Among them, two compounds 12b and 12c exhibited high inhibitory activities against SARS-CoV-2 3CLpro. Further investigations suggested that 12b with an acrylate warhead displayed potent activity against HCoV-OC43 (EC50 = 97 nM) and SARS-CoV-2 replicon (EC50 = 45 nM) and low cytotoxicity (CC50 > 10 µM) in Huh7 cells. Taken together, this study devised two series of 3CLpro inhibitors and provided the potent SARS-CoV-2 3CLpro inhibitor (12b) which may be used for treating coronavirus infections.

Postacute Sequelae of COVID (PASC or Long COVID): An Evidenced-Based Approach.

While the acute manifestations of infectious diseases are well known, in some individuals, symptoms can either persist or appear after the acute period. Postviral fatigue syndromes are recognized with other viral infections and are described after coronavirus disease 2019 (COVID-19). We have a growing number of individuals with symptoms that persist for weeks, months, and years. Here, we share the evidence regarding the abnormalities associated with postacute sequelae of COVID-19 (PASC) and therapeutics. We describe physiological and biochemical abnormalities seen in individuals reporting PASC. We describe the several evidence-based interventions to offer patients. It is expected that this growing understanding of the mechanisms driving PASC and the benefits seen with certain therapeutics may not only lead to better outcomes for those with PASC but may also have the potential for understanding and treating other postinfectious sequelae.

Physical Activity and Neurocognitive Symptoms in Older Adults During COVID-19 Pandemic.

Objectives: Examine whether physical activity (PA) changes during the COVID-19 pandemic were related to subjective cognitive decline (SCD), depression, and anxiety in older adults and whether these varied by sociodemographic variables. Methods: 301 older adults completed an online survey between May and October 2020 and 3 months later, including self-report questionnaires of SCD, depression, and anxiety. PA changes were determined with a question. Results: 60% of participants reported decreased PA. Those who reduced their PA were more likely to be from low to middle income and younger. PA increase was related to less SCD and depressive symptoms compared to those who decreased it. Participants who maintained their PA had fewer SCD concerns, depressive, and anxiety symptoms than those who decreased it. Discussion: Reducing PA was associated with worse neuropsychiatric and cognitive symptoms. Encouraging older adults to increase PA may help mitigate some of the pandemic's adverse effects on psychological well-being.

Routine blood parameters as auxiliary diagnostic tools for Mycoplasma pneumoniae infection in children.

Introduction. Recently, the incidence of Mycoplasma pneumoniae (M. pneumoniae) infection in children has been increasing annually. Early differential diagnosis of M. pneumoniae infection can not only avoid the abuse of antibiotics, but also is essential for early treatment and reduction of transmission.Gap statement. The change of routine blood parameters may have important clinical significance for the diagnosis of M. pneumoniae infection, but it has not been reported so far.Aim. This study aims to establish a predictive model for M. pneumoniae infection and explore the changes and clinical value of routine blood parameters in children with M. pneumoniae infection, serving as auxiliary indicators for the diagnosis and differentiation of clinical M. pneumoniae infection.Methodology. A total of 770 paediatric patients with respiratory tract infections were enrolled in this study, including 360 in the M. pneumoniae group, 40 in the SARS-CoV-2 group, 200 in the influenza A virus group, and 170 in the control group. The differences of routine blood parameters among all groups were compared, and risk factors were analysed using multivariate logistics analysis, and the diagnostic efficacy of differential indicators using ROC curves.Results. This study revealed that Mono% (OR: 3.411; 95% CI: 1.638-7.102; P=0.001) was independent risk factor associated with M. pneumoniae infection, and Mono% (AUC=0.786, the optimal cutoff at 7.8%) had a good discriminative ability between patients with M. pneumoniae infection and healthy individuals. Additionally, Mono% (OR: 0.424; 95% CI: 0.231-0.781; P=0.006) and Lymp% (OR: 0.430; 95% CI: 0.246-0.753; P=0.003) were independent risk factors for distinguishing M. pneumoniae infection from influenza A virus infection, and the Lymp% (AUC=0.786, the optimal cutoff at 22.1%) and Net% (AUC=0.761, the optimal cutoff at 65.2%) had good discriminative abilities between M. pneumoniae infection and influenza A infection. Furthermore, platelet distribution width (OR: 0.680; 95% CI: 0.538-0.858; P=0.001) was independent risk factor for distinguishing M. pneumoniae infection from SARS-CoV-2 infection. Meanwhile, the ROC curve demonstrated that PDW (AUC=0.786, the optimal cutoff at 15%) has a good ability to differentiate between M. pneumoniae infection and SARS-CoV-2 infection.Conclusion. This study demonstrates that routine blood parameters can be used as auxiliary diagnostic indicators for M. pneumoniae infection and provide reference for the diagnosis and differentiation of clinical M. pneumoniae infection.

Risk of Hearing Loss in Neonates and Toddlers with in Utero Exposure to SARS-CoV-2.

OBJECTIVE: Given the prevalence of neonatal hearing loss (HL) associated with intrauterine viral exposures, the goal of this study is to provide information on neonatal HL in the context of the COVID-19 pandemic. METHODS: Data were drawn from the COVID-19 Mother Baby Outcomes (COMBO) Initiative. 1007 participants completed the newborn hearing screen as part of routine clinical care (COMBO-EHR cohort) and 555 completed the National Survey of Children's Health (NSCH) at 2 and/or 3 years of age for research purposes (COMBO-RSCH cohort). Maternal SARS-CoV-2 infection status during pregnancy was determined through electronic health records and maternal-reported questionnaires. RESULTS: In adjusted multivariate logistic regression models covarying for newborn age at assessment, mode of delivery, and gestational age at delivery, there was no significant association between intrauterine SARS-CoV-2 exposure and newborn hearing screening failure (OR = 1.05, 95% CI = 0.39-2.42, p = 0.91) in the COMBO-EHR cohort. In the COMBO-RSCH cohort, there were similar non-significant associations between intrauterine exposure to SARS-CoV-2 and maternal-reported concern for HL on the NSCH (OR = 1.19 [95% CI = 0.30-4.24], p = 0.79). CONCLUSION: There is no association between intrauterine exposure to SARS-CoV-2 and failed hearing screen in neonates. Similarly, based on the NSCH, there is no association between intrauterine exposure to SARS-CoV-2 and maternal-reported concern for hearing in toddlers. These results offer reassurance given the widespread nature of this pandemic with tens of millions of fetuses having a history of intrauterine exposure. LEVEL OF EVIDENCE: Level 4 Laryngoscope, 2024.

From Viral Infections to Alzheimer's Disease: Unveiling the Mechanistic Links Through Systems Bioinformatics.

BACKGROUND: Emerging evidence suggests that viral infections may contribute to Alzheimer's disease (AD) onset and/or progression. However, the extent of their involvement and the mechanisms through which specific viruses increase AD susceptibility risk remain elusive. METHODS: We used an integrative systems bioinformatics approach to identify viral-mediated pathogenic mechanisms, by which Herpes Simplex Virus 1 (HSV-1), Human Cytomegalovirus (HCMV), Epstein-Barr virus (EBV), Kaposi Sarcoma-associated Herpesvirus (KSHV), Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), Influenza A Virus (IAV) and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) could facilitate AD pathogenesis via virus-host protein-protein interactions (PPIs). We also explored potential synergistic pathogenic effects resulting from herpesvirus reactivation (HSV-1, HCMV, and EBV) during acute SARS-CoV-2 infection, potentially increasing AD susceptibility. RESULTS: Herpesviridae members (HSV-1, EBV, KSHV, HCMV) impact AD-related processes like amyloid-ß (Aß) formation, neuronal death, and autophagy. Hepatitis viruses (HBV, HCV) influence processes crucial for cellular homeostasis and dysfunction, they also affect microglia activation via virus-host PPIs. Reactivation of HCMV during SARS-CoV-2 infection could potentially foster a lethal interplay of neurodegeneration, via synergistic pathogenic effects on AD-related processes like response to unfolded protein, regulation of autophagy, response to oxidative stress, and Aß formation. CONCLUSIONS: These findings underscore the complex link between viral infections and AD development. Viruses impact AD-related processes through shared and distinct mechanisms, potentially influencing variations in AD susceptibility.

T cell responses to repeated SARS-CoV-2 vaccination and breakthrough infections in patients on TNF inhibitor treatment: a prospective cohort study.

BACKGROUND: Understanding cellular responses to SARS-CoV-2 immunisations is important for informing vaccine recommendations in patients with inflammatory bowel disease (IBD) and other vulnerable patients on immunosuppressive therapies. This study investigated the magnitude and quality of T cell responses after multiple SARS-CoV-2 vaccine doses and COVID-19 breakthrough infection. METHODS: This prospective, observational study included patients with IBD and arthritis on tumour necrosis factor inhibitors (TNFi) receiving up to four SARS-CoV-2 vaccine doses. T cell responses to SARS-CoV-2 peptides were measured by flow cytometry before and 2-4 weeks after vaccinations and breakthrough infection to assess the frequency and polyfunctionality of responding cells, along with receptor-binding domain (anti-RBD) antibodies. FINDINGS: Between March 2, 2021, and December 20, 2022, 143 patients (118 IBD, 25 arthritis) and 73 healthy controls were included. In patients with either IBD or arthritis, humoral immunity was attenuated compared to healthy controls (median anti-RBD levels 3391 vs. 6280 BAU/ml, p = 0.008) after three SARS-CoV-2 vaccine doses. Patients with IBD had comparable quantities (median CD4 0.11% vs. 0.11%, p = 0.26, CD8 0.031% vs. 0.047%, p = 0.33) and quality (polyfunctionality score: 0.403 vs. 0.371, p = 0.39; 0.105 vs. 0.101, p = 0.87) of spike-specific T cells to healthy controls. Patients with arthritis had lower frequencies but comparable quality of responding T cells to controls. Breakthrough infection increased spike-specific CD8 T cell quality and T cell responses against non-spike peptides. INTERPRETATION: Patients with IBD on TNFi have T cell responses comparable to healthy controls despite attenuated humoral responses following three vaccine doses. Repeated vaccination and breakthrough infection increased the quality of T cell responses. Our study adds evidence that, in the absence of other risk factors, this group may in future be able to follow the general recommendations for COVID-19 vaccines. FUNDING: South-Eastern Norway Regional Health Authority, Coalition for Epidemic Preparedness Innovations (CEPI), Norwegian Institute of Public Health, Akershus University Hospital, Diakonhjemmet Hospital.

Delivery of SARS-CoV-2 spike and membrane genes in a single Baculoviral vector enhance the immune breadth against SARS-CoV-2 variants of concern.

Although the coronavirus pandemic has ended, new variants of concern (VOCs) continue to emerge. Therefore, novel vaccines targeting VOCs are highly warranted. We initially constructed three recombinant baculovirus-vectored vaccines (AcHERV-COVID19S) carrying the spike genes of the SARS-CoV-2 prototype, Delta, and Omicron BA.1 variants. However, the SARS-CoV-2 spike gene alone could not provide protection against multiple VOCs. To develop a universal vaccine, we constructed a recombinant baculovirus-vectored vaccine (AcHERV-COVID19 OmiM) by introducing the M gene, which is conserved among VOCs, as a secondary cellular immune antigen in addition to the S gene. AcHERV-COVID19 OmiM could provide higher protection against SARS-CoV-2 variants (prototype, Delta, BA.5 and XBB.1) compared with that of AcHERV-COVID19S. The membrane protein of SARS-CoV-2 synergizes with the S gene, thereby enhancing both humoral and cellular immunity against VOCs. Although AcHERV-COVID19 OmiM may not provide sterile protection against new variants, it may help reduce symptoms and curb viral transmission.

Act fast, stop COVID: The successful implementation of the first decentralised Victorian COVID-19 contact tracing and monitoring unit.

OBJECTIVES: To describe the operational model, epidemiology and outcomes of COVID-19 cases managed by the first decentralised Victorian Public Health Unit (PHU) in the Barwon South-West (BSW) region in 2020. METHODS: The Barwon Health team used a clinician-led, locally-based interprofessional model of care, combining clinical care and monitoring, contact tracing and public health measures. RESULTS: From 7th March to 5th October 2020, 575 confirmed COVID-19 cases (82 in Wave 1; 493 in Wave 2) were identified in residents of the BSW region. Overall, 4.7% were admitted to local hospitals (0.7% to intensive care units) and 1.7% died. COVID-19 incidence in the region was 129 cases/100,000. Wave 2 in the region featured community transmission in high-risk settings and among culturally and linguistically diverse and mobile populations. Within 3 months of the initial local case in Wave 2, SARS-COV-2 was eliminated from the community. CONCLUSIONS: A local interprofessional model of care was key to the containment of community transmission and complex outbreaks with the elimination of COVID-19 in the community. IMPLICATIONS FOR PUBLIC HEALTH: Key successes and learnings from the BSW PHU contributed to the improvement of statewide systems and responses and provided an impetus for the implementation of a decentralised public health model for Victoria.

Unlocking Trehalose's Versatility: A Comprehensive Journey from Biosynthesis to Therapeutic Applications.

For over forty years, a sugar of rare configuration known as trehalose (two molecules of glucose linked at their 1-carbons), has been recognised for more than just its roles as a storage compound. The ability of trehalose to protect an extensive range of biological materials, for instance cell lines, tissues, proteins and DNA, has sparked considerable interest in the biotechnology and pharmaceutical industries. Currently, trehalose is now being investigated as a promising therapeutic candidate for human use, as it has shown potential to reduce disease severity in various experimental models. Despite its diverse biological effects, the precise mechanism underlying this observation remain unclear. Therefore, this review delves into the significance of trehalose biosynthesis pathway in the development of novel drug, investigates the inhibitors of trehalose synthesis and evaluates the binding efficiency of T6P with TPS1. Additionally, it also emphasizes the knowledge about the protective effect of trehalose on modulation of autophagy, combating viral infections, addressing the conditions like cancer and neurodegenerative diseases based on the recent advancement. Furthermore, review also highlight the trehalose's emerging role as a surfactant in delivering monoclonal antibodies that will further broadening its potential application in biomedicines.

Clinical practice guidelines and expert consensus statements on rehabilitation for patients with COVID-19: a systematic review.

OBJECTIVES: To appraise the quality of clinical practice guidelines (CPGs) and expert consensus statements on rehabilitation for patients with COVID-19, summarise recommendations of rehabilitation assessments and interventions and evaluate the heterogeneity of the recommendations. DESIGN: Systematic review. DATA SOURCES: PubMed and Embase databases and five online guideline repositories: The National Guideline Clearinghouse, Guidelines International Network, Scottish Intercollegiate Guidelines Network, National Institute for Health and Clinical Excellence and WHO were searched from their inception to August 2024. In addition, we reviewed reference lists of eligible citations and searched the grey literature on the relevant websites. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included CPGs and expert consensus statements which provided information about rehabilitation of patients with COVID-19. To be eligible, the CPGs and expert consensus statements were issued in English by a nationally or internationally recognised government authority, medical/academic society or organisation. If there were multiple versions of the guidelines, we included the latest one. The translations, interpretations and abstracts of guidelines were excluded. DATA EXTRACTION AND SYNTHESIS: All recommendations on rehabilitation assessments and interventions for COVID-19 were extracted and summarised. Two reviewers independently evaluated the methodological quality with the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument, and two other reviewers assessed the reporting quality using the Reporting Items for Practice Guidelines in Healthcare (RIGHT) statement of included CPGs and expert consensus statements. We used the Measurement Scale of Rate of Agreement to evaluate the heterogeneity of the recommendations in different CPGs and expert consensus statements. RESULTS: A total of 31 CPGs and expert consensus statements were included. 14 guidelines provided recommendations for rehabilitation assessments. At the early, development, critical and recovery stages of COVID-19, the most frequently recommended were exercise therapy (25.8%, 35.5%, 25.8% and 58.1%, respectively). According to AGREE II, 17 included guidelines were assessed as low methodological quality (35%-56%), 10 guidelines were rated as moderate quality (46%- 62%) and four had high quality (69%-79%). Among 31 eligible guidelines, the reporting rate of 22 items in the RIGHT checklist ranged from 10% to 100%. The included guidelines were consistent with the reference guidelines (80%-100%). Only one guideline existed minor (60%-80%) disagreements in respiratory muscle training relative to the reference guideline. CONCLUSIONS: Rehabilitation assessments and interventions should be implemented consistently throughout the entire process of COVID-19. The recommendations should be tailored to each stage of COVID-19. The methodological and reporting qualities of several guidelines remain suboptimal. Therefore, developers should adhere strictly to the AGREE II standard and RIGHT checklist to formulate and publish CPGs and expert consensus statements with high quality. PROSPERO REGISTRATION NUMBER: CRD42020190761.

Chemokine receptors in COVID-19 infection.

Chemokine receptors play diverse roles in the immune response against pathogens by recruiting innate and adaptive immune cells to sites of infection. However, their involvement could also be detrimental, causing tissue damage and exacerbating respiratory diseases by triggering histological alterations such as fibrosis and remodeling. This chapter reviews the role of chemokine receptors in the immune defense against SARS-CoV-2 infection. In COVID-19, CXCR3 is expressed mainly in T cells, and its upregulation is related to an increase in SARS-CoV-2-specific antibodies but also to COVID-19 severity. CCR5 is a key player in T-cell recruitment, and its suppression leads to reduced inflammation and viremia levels. Conversely, CXCR6 is implicated in the aberrant migration of memory T cells within airways. On the other hand, increased CCR4+ cells in the blood and decreased CCR4+ cells in lung cells are associated with severe COVID-19. Additionally, CCR2 is associated with an increase in macrophage recruitment to lung tissues. Elevated levels of CXCR1 and CXCR2, which are predominantly expressed in neutrophils, are associated with the severity of the disease, and finally, the expression of CX3CR1 in cytotoxic T lymphocytes affects the retention of these cells in lung tissues, thereby impacting the severity of COVID-19. Despite the efforts of many clinical trials to find effective therapies for COVID-19 using chemokine receptor inhibitors, no conclusive results have been found due to the small number of patients, redundancy, and co-expression of chemokine receptors by immune cells, which explains the difficulty in finding a single therapeutic target or effective treatment.