Reduced risk for Omicron SARS-CoV-2 infection observed in older adults with hybrid immunity.

BACKGROUND: Hybrid SARS-CoV-2 immunity may provide longer duration protection against severe SARS-CoV-2 infection and hospitalisation than purely vaccine-derived immunity. Older adults represent a high-risk group for severe disease, yet available data is skewed towards younger adults. METHODS: A prospective longitudinal study at a large London long-term care facility (LTCF) was conducted from March 2020 to April 2022 to assess the effect of hybrid versus vaccine-only immunity on SARS-CoV-2 infection in older adults during Omicron variant dominance. Hybrid immunity was assessed by a combination of SARS-CoV-2 polymerase chain reaction testing weekly (asymptomatic screening) and as required (symptomatic testing), as well as serial SARS-CoV-2 serology. RESULTS: 280 participants (median age 82 yrs, IQR 76-88 yrs; 95.4% male) were followed up. 168/280 (60%) had evidence of hybrid immunity prior to the Omicron variant wave. Participants with hybrid immunity had substantially lower odds of acquiring COVID-19 infection during the Omicron wave compared to those with vaccine-only immunity (unadjusted odds ratio 0.26, 95% CI 0.14-0.47, chi-squared P < .0001). Participants with hybrid immunity had an odds ratio of 0.40 (0.19-0.79) for asymptomatic infection and 0.15 (0.06-0.34) for symptomatic infection (Likelihood ratio test, P < .0001). DISCUSSION: Our data highlight potential opportunities to target ongoing booster vaccination campaigns for those most at risk of severe infection. Reporting of data in older adults will be of particular value to examine the effect of hybrid immunity as new variants continue to emerge and vaccination strategies evolve.

Lactate cross-talk in host-pathogen interactions.

Lactate is the main product generated at the end of anaerobic glycolysis or during the Warburg effect and its role as an active signalling molecule is increasingly recognised. Lactate can be released and used by host cells, by pathogens and commensal organisms, thus being essential for the homeostasis of host-microbe interactions. Infection can alter this intricate balance, and the presence of lactate transporters in most human cells including immune cells, as well as in a variety of pathogens (including bacteria, fungi and complex parasites) demonstrates the importance of this metabolite in regulating host-pathogen interactions. This review will cover lactate secretion and sensing in humans and microbes, and will discuss the existing evidence supporting a role for lactate in pathogen growth and persistence, together with lactate's ability to impact the orchestration of effective immune responses. The ubiquitous presence of lactate in the context of infection and the ability of both host cells and pathogens to sense and respond to it, makes manipulation of lactate a potential novel therapeutic strategy. Here, we will discuss the preliminary research that has been carried out in the context of cancer, autoimmunity and inflammation.

Variability in detection of SARS-CoV-2-specific antibody responses following mild infection: a prospective multicentre cross-sectional study, London, United Kingdom, 17 April to 17 July 2020.

IntroductionImmunoassays targeting different SARS-CoV-2-specific antibodies are employed for seroprevalence studies. The degree of variability between immunoassays targeting anti-nucleocapsid (anti-NP; the majority) vs the potentially neutralising anti-spike antibodies (including anti-receptor-binding domain; anti-RBD), particularly in mild or asymptomatic disease, remains unclear.AimsWe aimed to explore variability in anti-NP and anti-RBD antibody detectability following mild symptomatic or asymptomatic SARS-CoV-2 infection and analyse antibody response for correlation with symptomatology.MethodsA multicentre prospective cross-sectional study was undertaken (April-July 2020). Paired serum samples were tested for anti-NP and anti-RBD IgG antibodies and reactivity expressed as binding ratios (BR). Multivariate linear regression was performed analysing age, sex, time since onset, symptomatology, anti-NP and anti-RBD antibody BR.ResultsWe included 906 adults. Antibody results (793/906; 87.5%; 95% confidence interval: 85.2-89.6) and BR strongly correlated (ρ = 0.75). PCR-confirmed cases were more frequently identified by anti-RBD (129/130) than anti-NP (123/130). Anti-RBD testing identified 83 of 325 (25.5%) cases otherwise reported as negative for anti-NP. Anti-NP presence (+1.75/unit increase; p < 0.001), fever (≥ 38°C; +1.81; p < 0.001) or anosmia (+1.91; p < 0.001) were significantly associated with increased anti-RBD BR. Age (p = 0.85), sex (p = 0.28) and cough (p = 0.35) were not. When time since symptom onset was considered, we did not observe a significant change in anti-RBD BR (p = 0.95) but did note decreasing anti-NP BR (p < 0.001).ConclusionSARS-CoV-2 anti-RBD IgG showed significant correlation with anti-NP IgG for absolute seroconversion and BR. Higher BR were seen in symptomatic individuals, particularly those with fever. Inter-assay variability (12.5%) was evident and raises considerations for optimising seroprevalence testing strategies/studies.

Development of a high-sensitivity ELISA detecting IgG, IgA and IgM antibodies to the SARS-CoV-2 spike glycoprotein in serum and saliva.

Detecting antibody responses during and after SARS-CoV-2 infection is essential in determining the seroepidemiology of the virus and the potential role of antibody in disease. Scalable, sensitive and specific serological assays are essential to this process. The detection of antibody in hospitalized patients with severe disease has proven relatively straightforward; detecting responses in subjects with mild disease and asymptomatic infections has proven less reliable. We hypothesized that the suboptimal sensitivity of antibody assays and the compartmentalization of the antibody response may contribute to this effect. We systematically developed an ELISA, optimizing different antigens and amplification steps, in serum and saliva from non-hospitalized SARS-CoV-2-infected subjects. Using trimeric spike glycoprotein, rather than nucleocapsid, enabled detection of responses in individuals with low antibody responses. IgG1 and IgG3 predominate to both antigens, but more anti-spike IgG1 than IgG3 was detectable. All antigens were effective for detecting responses in hospitalized patients. Anti-spike IgG, IgA and IgM antibody responses were readily detectable in saliva from a minority of RT-PCR confirmed, non-hospitalized symptomatic individuals, and these were mostly subjects who had the highest levels of anti-spike serum antibodies. Therefore, detecting antibody responses in both saliva and serum can contribute to determining virus exposure and understanding immune responses after SARS-CoV-2 infection.

Prosthetic hip joint infection by Bacillus Calmette-Guerin therapy following intravesical instillation for bladder cancer identified using whole-genome sequencing: a case report.

BACKGROUND: Joint replacement is an effective intervention and prosthetic joint infection (PJI) is one of the most serious complications of such surgery. Diagnosis of PJI is often complex and requires multiple modalities of investigation. We describe a rare cause of PJI which highlights these challenges and the role of whole-genome sequencing to achieve a rapid microbiological diagnosis to facilitate prompt and appropriate management. CASE PRESENTATION: A 79-year-old man developed chronic hip pain associated with a soft-tissue mass, fluid collection and sinus adjacent to his eight-year-old hip prosthesis. His symptoms started after intravesical Bacillus Calmette-Guerin (BCG) therapy for bladder cancer. Synovasure™ and 16S polymerase chain reaction (PCR) tests were negative, but culture of the periarticular mass and genome sequencing diagnosed BCG infection. He underwent a two-stage joint revision and a prolonged duration of antibiotic therapy which was curative. CONCLUSIONS: BCG PJI after therapeutic exposure can have serious consequences, and awareness of this potential complication, identified from patient history, is essential. In addition, requesting appropriate testing is required, together with recognition that traditional diagnostics may be negative in non-pyogenic PJI. Advanced molecular techniques have a role to enhance the timely management of these infections.

Sensitive Detection of SARS-CoV-2-Specific Antibodies in Dried Blood Spot Samples.

Dried blood spot (DBS) samples can be used for the detection of severe acute respiratory syndrome coronavirus 2 spike antibodies. DBS sampling is comparable to matched serum samples with a relative 98.1% sensitivity and 100% specificity. Thus, DBS sampling offers an alternative for population-wide serologic testing in the coronavirus pandemic.

Diagnosis of Febrile Illnesses Other Than Ebola Virus Disease at an Ebola Treatment Unit in Sierra Leone.

Patients with febrile illnesses presenting to an Ebola treatment unit in Sierra Leone had a wide range of diagnoses other than Ebola virus disease. Rapid diagnostic tests were useful in confirming these diagnoses, reducing the length of patient stay with valuable consequences. These alternative diagnoses should assist in future planning.

Time-to-detection in culture predicts risk of Mycobacterium tuberculosis transmission: a cohort study.

BACKGROUND: Contact screening is an essential component of all tuberculosis control strategies. We hypothesize that time-to-detection (TTD) in liquid culture of spontaneously produced sputum samples may help identify index cases at high risk of transmission. METHODS: We studied retrospectively a cohort of patients with pulmonary tuberculosis in Birmingham, United Kingdom (January 2010-December 2012). We studied the correlation of TTD with the risk of transmission of infection from index cases to contacts and compared this with sputum microscopy. Chest radiographs (CXRs) were graded from 0 to 6 (0, no radiographic evidence of disease; 5, bilateral cavitation; and 6, miliary disease). RESULTS: Of the 184 cases of pulmonary tuberculosis reported during the study period, 111 were included in the final study, and these generated 825 contacts. A transmission event (new latent or active tuberculosis) was identified in 165 contacts (transmission rate 0.20). Short TTD (<9 days) was associated with an increased risk of transmission (odds ratio, 2.56; P < .001), and this relationship persisted after adjusting for potential confounders. A 1-point increase in CXR grade correlated with a 3.2-day decrease in TTD (P < .001), and this correlation persisted after adjustment for potential confounders. CONCLUSIONS: TTD < 9 days identifies patients at high risk of transmitting tuberculosis and is superior to sputum smear. CXR grade at diagnosis predicts patients with short TTD. Our findings have the potential to guide the organization and prioritization of contact investigations in similar settings.

Inflammatory and myeloid-associated gene expression before and one day after infant vaccination with MVA85A correlates with induction of a T cell response.

BACKGROUND: Tuberculosis (TB) remains a global health problem, with vaccination likely to be a necessary part of a successful control strategy. Results of the first Phase 2b efficacy trial of a candidate vaccine, MVA85A, evaluated in BCG-vaccinated infants were published last year. Although no improvement in efficacy above BCG alone was seen, cryopreserved samples from this trial provide an opportunity to study the immune response to vaccination in this population. METHODS: We investigated blood samples taken before vaccination (baseline) and one and 28 days post-vaccination with MVA85A or placebo (Candin). The IFN-γ ELISpot assay was performed at baseline and on day 28 to quantify the adaptive response to Ag85A peptides. Gene expression analysis was performed at all three timepoints to identify early gene signatures predictive of the magnitude of the subsequent adaptive T cell response using the significance analysis of microarrays (SAM) statistical package and gene set enrichment analysis. RESULTS: One day post-MVA85A, there is an induction of inflammatory pathways compared to placebo samples. Modules associated with myeloid cells and inflammation pre- and one day post-MVA85A correlate with a higher IFN-γ ELISpot response post-vaccination. By contrast, previous work done in UK adults shows early inflammation in this population is not associated with a strong T cell response but that induction of regulatory pathways inversely correlates with the magnitude of the T cell response. This may be indicative of important mechanistic differences in how T cell responses develop in these two populations following vaccination with MVA85A. CONCLUSION: The results suggest the capacity of MVA85A to induce a strong innate response is key to the initiation of an adaptive immune response in South African infants but induction of regulatory pathways may be more important in UK adults. Understanding differences in immune response to vaccination between populations is likely to be an important aspect of developing successful vaccines and vaccination strategies. TRIAL REGISTRATION: ClinicalTrials.gov number NCT00953927.

Screening for latent tuberculosis and gastrointestinal parasite infections in Gurkha recruits: research driving policy change.

Nepalese Gurkha soldiers are recruited from a country endemic for a number of infectious diseases, including tuberculosis and gastrointestinal parasites. This article describes a prospective cohort study which investigated screening strategies for these infections among Gurkha recruits arriving in the UK to begin basic training. Several recommendations were made as a result of the study which were supported for early implementation and subsequently fully adopted. Military screening and treatment policies have been directly influenced by this research which also has translational application to similar migrant civilian populations.

IgG glycosylation associates with risk of progression from latent to active tuberculosis.

OBJECTIVES: Glycosylation motifs shape antibody structure, stability and antigen affinity and play an important role in antibody localization and function. Serum IgG glycosylation profiles are significantly altered in infectious diseases, including tuberculosis (TB), but have not been studied in the context of progression from latent to active TB. METHODS: We performed a longitudinal study of paired bulk IgG glycosylation and transcriptomic profiling in blood from individuals with active TB (ATB) or latent TB infection (LTBI) before and after treatment. RESULTS: We identified that a combination of two IgG1 glycosylation traits were sufficient to distinguish ATB from LTBI with high specificity and sensitivity, prior to, and after treatment. Importantly, these two features positively correlated with previously defined cellular and RNA signatures of ATB risk in LTBI, namely monocyte to lymphocyte ratio and the expression of interferon (IFN)-associated gene signature of progression (IFN-risk signature) in blood prior to treatment. Additional glycosylation features at higher prevalence in LTBI individuals with high expression of the IFN-risk signature prior to treatment included fucosylation on IgG1, IgG2 and IgG3. CONCLUSIONS: Together, our results demonstrate that bulk IgG glycosylation features could be useful in stratifying the risk of LTBI reactivation and progression to ATB.

Gastrointestinal parasite infections in Nepalese Gurkha recruits arriving in the United Kingdom from 2012-2020.

BACKGROUND: Gastrointestinal parasite (GIP) infections are a major cause of global morbidity, infecting hundreds of millions of people each year and potentially leading to lifelong infection and serious complications. Few data exist on screening for GIP infections in migrants entering the UK or on the current performance of different traditional diagnostic approaches. This study aimed to describe the prevalence of GIP infections in Nepalese Gurkha recruits screened on arrival in the UK. METHODOLOGY/PRINCIPAL FINDINGS: We present a retrospective analysis of data from screening male adults (18-21 years) who arrived in the UK from Nepal between 2012 and 2020. Three separate faecal samples were obtained from participants at weekly intervals and processed for formalin-ethyl acetate (FEA) concentration/light microscopy and charcoal culture. Serum samples were analysed for IgG antibodies to Strongyloides stercoralis by ELISA. Results were available from 2,263 participants, of whom 463 (20.5%, 95% CI 18.8%-22.2%) had a positive diagnostic test for at least one GIP infection. A total of 525 potential infections were identified. Giardia duodenalis was most common (231/2263, 10.2%), followed by S. stercoralis (102/2263, 4.5%), and hookworm species (86/2263, 3.8%). Analysis (microscopy and culture) of the initial stool sample diagnosed only 244/427 (57.1%) faecally identified pathogens, including 41/86 (47.7%) hookworm infections. The proportion of participants infected with any GIP showed a downward trend over the study period. Log-binomial regression showed risk of infection decreasing by 6.1% year-on-year (95% CI 3.2% - 9.0%). This was driven predominantly by a fall in hookworm, S. stercoralis and Trichuris trichiura prevalence. CONCLUSIONS/SIGNIFICANCE: The level of potentially pathogenic GIP infection in young Nepalese men migrating to the UK is high (20.5%) and requires a combined diagnostic approach including serology and analysis of multiple stool samples incorporating specialised parasitological methods. Advances in molecular approaches may optimise and simplify the intensive screening strategy required.

Conflict and catastrophe-related severe burn injuries: A challenging setting for antimicrobial decision-making.

Severe burns are a major component of conflict-related injuries and can result in high rates of mortality. Conflict and disaster-related severe burn injuries present unique challenges in logistic, diagnostic and treatment options, while wider conflict is associated with driving local antimicrobial resistance. We present a targeted review of available literature over the last 10 years on the use of systemic antimicrobial antibiotics in this setting and, given limited available data, provide an expert consensus discussion. While international guidelines do not tend to recommend routine use of prophylactic systemic antibiotics, the challenges of conflict settings and potential for polytrauma are likely to have ongoing impacts on antimicrobial decision-making and use. Efforts must be made to develop a suitable evidence base in this unique setting. In the interim, a pragmatic approach to balancing selective pressures of antimicrobial use with realistic access is possible.

Respiratory infections in the military.

Military training facilities and operational theatres, and the stressful activities undertaken in such settings, are unique. Military personnel living and working in these environments are at considerable risk of the acquisition and onward transmission of a variety of respiratory infections. While these generally cause mild illness, severe disease may occur with significant associated morbidity and, occasionally, mortality. Epidemic outbreaks among military personnel may have a significant detrimental impact on training schedules and operational effectiveness. The recognition of the burden of such illness among British military personnel, and the development of strategies required to prevent or limit negative impacts, can only be achieved through the use of comprehensive laboratory-based surveillance programmes.

Tuberculosis and the military.

Tuberculosis (TB) causes significant morbidity and mortality among the global civilian population. Historically, TB has also been responsible for a considerable burden of disease among military populations during periods of both peace and conflict. TB will continue to be of importance to the military for several reasons. Military units live and work in confined environments, personnel may deploy to areas highly endemic for TB where there is the potential to be exposed to infected local communities, and they undertake physiologically stressful activities during training and operations. These are just a few of the factors that may increase the risk of acquiring, developing and transmitting TB among military personnel. This review examines the military relevance of TB in the modern era within the context of epidemiological, pathological and clinical considerations of this ancient disease.

Excretory-secretory products from adult helminth Nippostrongylus brasiliensis have in vitro bactericidal activity.

Introduction. Intestinal helminths and microbiota share the same anatomical niche during infection and are likely to interact either directly or indirectly. Whether intestinal helminths employ bactericidal strategies that influence their microbial environment is not completely understood.Hypothesis. In the present study, the hypothesis that the adult hookworm Nippostrongylus brasiliensis produces molecules that impair bacterial growth in vitro, is tested.Aim. To investigate the in vitro bactericidal activity of Nippostrongylus brasiliensis against commensal and pathogenic bacteria.Methodology. The bactericidal effect of somatic extract and excretory-secretory products of adult Nippostrongylus brasiliensis on Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Salmonella enterica serovar Typhimurium, and Klebsiella pneumoniae) bacteria was assessed using growth assays. Minimum inhibitory concentration and minimum bactericidal concentration assays were performed using excretory-secretory products released from the pathogen.Results. Broad-spectrum in vitro bactericidal activity in excretory-secretory products, but not somatic extract of adult Nippostrongylus brasiliensis was detected. The bactericidal activity of excretory-secretory products was concentration-dependent, maintained after heat treatment, and preserved after repeated freezing and thawing.Conclusion. The results of this study demonstrate that helminths such as Nippostrongylus brasiliensis release molecules via their excretory-secretory pathway that have broad-spectrum bactericidal activity. The mechanisms responsible for this bactericidal activity remain to be determined and further studies aimed at isolating and identifying active bactericidal molecules are needed.

Induction of Siglec-FhiCD101hi eosinophils in the lungs following murine hookworm Nippostrongylus brasiliensis infection.

Helminth-induced eosinophils accumulate around the parasite at the site of infection, or in parasite-damaged tissues well after the helminth has left the site. The role of helminth-elicited eosinophils in mediating parasite control is complex. While they may contribute to direct parasite-killing and tissue repair, their involvement in long-term immunopathogenesis is a concern. In allergic Siglec-FhiCD101hi, eosinophils are associated with pathology. Research has not shown if equivalent subpopulations of eosinophils are a feature of helminth infection. In this study, we demonstrate that lung migration of rodent hookworm Nippostrongylus brasiliensis (Nb) results in a long-term expansion of distinct Siglec-FhiCD101hi eosinophil subpopulations. Nb-elevated eosinophil populations in the bone marrow and circulation did not present this phenotype. Siglec-FhiCD101hi lung eosinophils exhibited an activated morphology including nuclei hyper-segmentation and cytoplasm degranulation. Recruitment of ST2+ ILC2s and not CD4+ T cells to the lungs was associated with the expansion of Siglec-FhiCD101hi eosinophils. This data identifies a morphologically distinct and persistent subset of Siglec-FhiCD101hi lung eosinophils induced following Nb infection. These eosinophils may contribute to long-term pathology following helminth infection.

Hybrid immunity in older adults is associated with reduced SARS-CoV-2 infections following BNT162b2 COVID-19 immunisation.

BACKGROUND: Older adults, particularly in long-term care facilities (LTCF), remain at considerable risk from SARS-CoV-2. Data on the protective effect and mechanisms of hybrid immunity are skewed towards young adults precluding targeted vaccination strategies. METHODS: A single-centre longitudinal seroprevalence vaccine response study was conducted with 280 LCTF participants (median 82 yrs, IQR 76-88 yrs; 95.4% male). Screening by SARS-CoV-2 polymerase chain reaction with weekly asymptomatic/symptomatic testing (March 2020-October 2021) and serology pre-/post-two-dose Pfizer-BioNTech BNT162b2 vaccination for (i) anti-nucleocapsid, (ii) quantified anti-receptor binding domain (RBD) antibodies at three time-intervals, (iii) pseudovirus neutralisation, and (iv) inhibition by anti-RBD competitive ELISA were conducted. Neutralisation activity: antibody titre relationship was assessed via beta linear-log regression and RBD antibody-binding inhibition: post-vaccine infection relationship by Wilcoxon rank sum test. RESULTS: Here we show neutralising antibody titres are 9.2-fold (95% CI 5.8-14.5) higher associated with hybrid immunity (p < 0.00001); +7.5-fold (95% CI 4.6-12.1) with asymptomatic infection; +20.3-fold, 95% (CI 9.7-42.5) with symptomatic infection. A strong association is observed between antibody titre: neutralising activity (p < 0.00001) and rising anti-RBD antibody titre: RBD antibody-binding inhibition (p < 0.001), although 18/169 (10.7%) participants with high anti-RBD titre (>100BAU/ml), show inhibition <75%. Higher RBD antibody-binding inhibition values are associated with hybrid immunity and reduced likelihood of infection (p = 0.003). CONCLUSIONS: Hybrid immunity in older adults was associated with considerably higher antibody titres, neutralisation and inhibition capacity. Instances of high anti-RBD titre with lower inhibition suggests antibody quantity and quality as independent potential correlates of protection, highlighting added value of measuring inhibition over antibody titre alone to inform vaccine strategy.

Older adults continue to be at risk of COVID-19, particularly in residential care home settings. We investigated the effect of infection and vaccination on antibody development and subsequent SARS-CoV-2 infection in older adults. Antibodies are proteins that the immune system produces on infection or vaccination that can help respond to subsequent infection with SARS-CoV-2. We found that older adults produce antibodies to SARS-CoV-2 after 2-doses of Pfizer BioNTech BNT162b2 vaccine. The strongest immune responses were seen among those older adults who also had prior history of infection. The results highlight the importance of both antibody quality and quantity when considering possible indicators of protection against COVID-19 and supports the need for a third, booster, vaccination in this age group..

COVID-19 risk, attitudes and behaviour study (CRAB study): A knowledge, attitudes, and practise qualitative study of COVID-19 in the Royal Navy.

Introduction: Outbreaks of SARS-CoV-2 onboard maritime platforms spread rapidly and have high attack rates. The aim of the COVID-19 Risk, Attitudes and Behaviour (CRAB) study was to investigate the knowledge, attitudes, and practises in the Royal Navy in relation to COVID-19 prevention. Methods: The CRAB study was a cross-sectional survey, using a census sampling method, conducted in May and June 2021. An online questionnaire was distributed to all serving Royal Navy regular personnel using either the MyNavy application or via a QR code through email for a continuous 14 day period. The questionnaire was based on an existing validated questionnaire used for avian influenza epidemics. Questions investigated individual perceptions of COVID-19 seriousness, compliance with prevention methods, explored vaccination intention and vaccine hesitancy (unvaccinated individuals who declined or were unsure about receiving a COVID-19 vaccine). The chi-squared test of best fit was used to compare the demographic responses against the whole organisation, with p-value < 0.05 deemed significant. Odds ratios were used to investigate associations between demographic groups and responses to questions, with an odds ratio crossing 1.0 deemed non-significant. Results: The response rate was 6% (2,080/33,200), with 315 responses collated in the pilot phase and 1,765 in the main study phase. Male participants were less likely to rate COVID-19 as serious (OR 0.34; 95% CI: 0.23-0.49). BAME ethnicity (OR 2.41; 95% CI: 1.12-5.17) rated it as more serious. At the time of the study 62% of respondents had received one dose of a COVID-19 vaccine. In the 797 unvaccinated personnel, vaccine hesitancy accounted for 24.2% (193/797), of whom 136 were white males. Those who had a higher COVID-19 serious rating, the most significant factor for non-adherence to COVID-19 prevention measures in both vaccinated (OR 1.61 [95%CI: 1.20-2.17]) and vaccine-hesitant (OR 3.24 [95%CI: 1.63-6.41]) individuals was colleagues' non-adherence. The most trusted source of information on vaccines was provided by the Defence Medical Services (77.2% [1,606/2,080]). Conclusion: This study has identified reasons for COVID-19 protective measure adherence, sources of information trusted by respondents and vaccine hesitancy, in the Royal Navy. The questionnaire can be used to investigate attitudes and behaviours in future emerging infectious diseases.

Host Immune-Metabolic Adaptations Upon Mycobacterial Infections and Associated Co-Morbidities.

Mycobacterial diseases are a major public health challenge. Their causative agents include, in order of impact, members of the Mycobacterium tuberculosis complex (causing tuberculosis), Mycobacterium leprae (causing leprosy), and non-tuberculous mycobacterial pathogens including Mycobacterium ulcerans. Macrophages are mycobacterial targets and they play an essential role in the host immune response to mycobacteria. This review aims to provide a comprehensive understanding of the immune-metabolic adaptations of the macrophage to mycobacterial infections. This metabolic rewiring involves changes in glycolysis and oxidative metabolism, as well as in the use of fatty acids and that of metals such as iron, zinc and copper. The macrophage metabolic adaptations result in changes in intracellular metabolites, which can post-translationally modify proteins including histones, with potential for shaping the epigenetic landscape. This review will also cover how critical tuberculosis co-morbidities such as smoking, diabetes and HIV infection shape host metabolic responses and impact disease outcome. Finally, we will explore how the immune-metabolic knowledge gained in the last decades can be harnessed towards the design of novel diagnostic and therapeutic tools, as well as vaccines.