Temporal trends and regional variability in BRAF and KRAS genetic testing in Denmark (2010-2022): Implications for precision medicine.

OBJECTIVE: This study aims to evaluate the developments in the testing of Kirsten Rat Sarcoma viral oncogene homolog (KRAS) and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations across different cancer types and regions in Denmark from 2010 to 2022. STUDY DESIGN AND SETTING: Using comprehensive data from the Danish health registries, we linked molecular test results from the Danish Pathology Registry with cancer diagnoses from the Danish National Patient Registry between 2010 and 2022. We assessed the frequency and distribution of KRAS and BRAF mutations across all cancer types, years of testing, and the five Danish regions. RESULTS: The study included records of KRAS testing for 30 671 patients and BRAF testing for 30 860 patients. Most KRAS testing was performed in colorectal (78%) and lung cancer (18%), and BRAF testing in malignant melanoma (13%), colorectal cancer (67%), and lung cancer (12%). Testing rates and documentation mutational subtypes increased over time. Reporting of wildtype results varied between lung and colorectal cancer, with underreporting in lung cancer. Regional variations in testing and reporting were observed. CONCLUSION: Our study highlights substantial progress in KRAS and BRAF testing in Denmark from 2010 to 2022, evidenced by increased and more specific reporting of mutational test results, thereby improving the precision of cancer diagnosis and treatment. However, persistent regional variations and limited testing for cancer types beyond melanoma, colorectal, and lung cancer highlight the necessity for a nationwide assessment of the optimal testing approach.

Education, employment, and income among people living with cystic fibrosis across three decades - A matched cohort study using Danish health registries.

BACKGROUND: Past and ongoing advancements in cystic fibrosis (CF) care warrant long-term analysis of the societal impact of the condition. This study aims to evaluate changes in key socioeconomic factors across three decades among people living with CF (pwCF), compared with both the general population and an early-onset chronic disease population. METHODS: This nationwide, registry-based, matched cohort study included all pwCF ≥ 18 years in Denmark in the years 1990, 2000, 2010, and 2018. Each person living with CF was matched to five individuals in the general population and five individuals living with type 1 diabetes or juvenile arthritis based on age, sex, and municipality. RESULTS: The Danish adult CF population increased nearly fourfold from 88 in 1990 to 331 in 2018, and mean age increased by ten years. The educational level of pwCF was similar to the two comparator cohorts, while pwCF were less often in employment and more often permanently outside the labor force. Personal and household income levels of the CF cohort were higher than those of the comparator cohorts. CONCLUSIONS: The disadvantage in employment for pwCF remained, but, over time, the societal profiles of the one-year CF cohorts increasingly converged with those of the comparator cohorts, indicative of improved clinical management, extended life expectancy, and the supportive role of the Danish welfare system in reducing health inequalities. Further research should be done to evaluate the effects of the newly introduced modulator therapies on employment, considering the broader societal impact and impact on quality of life.

Immunogenicity of Bacillus Calmette-Guérin in pigs: potential as a translational model of non-specific effects of BCG.

Background: Clinical and immunological studies in humans show that the live attenuated Bacillus Calmette-Guérin (BCG) vaccine has beneficial non-specific effects, increasing resistance against diseases other than tuberculosis. The underlying mechanisms are currently being explored. The pig exhibits considerable physiological similarity to humans in anatomy and physiology, suggesting that similar responses to BCG could be expected. Studies of the non-specific effects of BCG in pigs are scarce. We investigated the feasibility of using pigs as a large animal model to investigate the non-specific immunological effects of BCG. Methods: In a series of experiments, we randomized newborn or young piglets from conventional farms to receiving BCG or placebo and investigated the persistence of live BCG bacteria in various tissues, the immunogenicity of BCG in ex vivo blood and in vitro stimulation assays, and the acute phase protein and clinical responses to heterologous infectious challenge with influenza A virus or Actinobacillus pleuropneumoniae. Results: The BCG vaccine was generally well tolerated. In contrast to humans, no skin reaction in the form of abscesses, ulcers, or scars was observed. Live BCG was recovered from draining lymph nodes in 2/13 animals 20 weeks after vaccination. Specific in vitro responses of IFN-γ to antigen-specific re-stimulation with mycobacterial antigen were increased but not TNF-responses to TLR2 or TLR4 agonists. A few genes were differentially expressed in blood after vaccination, including the antiviral genes RIG-I and CSF1, although the effect disappeared after correction for multiple testing. Clinical symptoms after heterologous bacterial or viral respiratory infections did not differ, nor did virus copies in nasopharyngeal samples after the challenge. However, the acute phase protein response was significantly reduced in BCG-vaccinated animals after influenza challenge but not after A. pleuropneumoniae challenge. Discussion: BCG was safe in pigs, inducing specific immunological responses, but our model did not corroborate the innate immunological responsiveness to BCG seen in humans. The dose of BCG or the bacterial and viral challenges may have been sub-optimal. Even so, the acute phase protein response to influenza infection was significantly reduced in BCG-vaccinated animals.

Predictors of serum- per- and polyfluoroalkyl substance (PFAS) concentrations among infants in Guinea-Bissau, West Africa.

BACKGROUND: Knowledge about PFAS exposure in Africa is limited. We have previously detected six types of PFAS in the serum of infants from Guinea-Bissau, West Africa. The aim of this study was to identify predictors of the infant serum-PFAS concentrations. METHODS: This cross-sectional study was based on a subset of data from a randomized controlled trial of early measles vaccination performed in 2012-2015 in three rural regions of Guinea-Bissau. Blood samples were obtained from 237 children aged 4-to-7 months, and six types of PFAS were quantified in serum. Location of residence was recorded, and information about predictors related to socioeconomic status as well as maternal and child characteristics were obtained through structured interviews with the mothers through routine surveillance. Associations between potential predictors and infant serum-PFAS concentrations were examined in linear regression models while adjusting for potential confounding and mediating factors as identified in a directed acyclic graph. RESULTS: Infants from the Cacheu region had the lowest concentrations of perfluorooctanoic acid (PFOA), while infants from the Oio region had the lowest concentrations of all other PFAS. Compared to infants from Oio, infant serum-perfluorooctane sulfonic acid (PFOS) concentrations were 94.1% (95% CI: 52.4, 147.1%) and 81.9% (95% CI: 45.7, 127.1%) higher in Cacheu and Biombo, respectively. Higher maternal age and lower parity were associated with slightly higher child-serum perfluorohexane sulfonic acid (PFHxS) concentrations, while infants with higher socioeconomic status and infants breastfed without supplementary solid foods at inclusion had higher average concentrations of most PFAS, although the confidence intervals were wide and overlapped zero. DISCUSSION: Location of residence was the most important determinant of serum-PFAS concentrations among Guinea-Bissau infants, indicating a potential role of diet as affected by the global spread of PFAS, but future studies should explore reasons for the regional differences in PFAS exposure.

KRAS G12C mutated advanced non-small cell lung cancer (NSCLC): Characteristics, treatment patterns and overall survival from a Danish nationwide observational register study.

OBJECTIVES: We aimed to characterize the advanced NSCLC population in terms of KRAS G12C prevalence, patient characteristics, and survival outcomes after the introduction of immunotherapies. MATERIALS AND METHODS: We identified adult patients diagnosed with advanced NSCLC between January 1, 2018 and June 30, 2021 using the Danish health registries. Patients were grouped by mutational status (any KRAS mutation, KRAS G12C, and KRAS/EGFR/ALK wildtype [Triple WT]). We analyzed KRAS G12C prevalence, patient and tumor characteristics, treatment history, time-to-next-treatment (TTNT), and overall survival (OS). RESULTS: We identified 7,440 patients of whom 40% (n = 2,969) were KRAS tested prior to the first line of therapy (LOT1). Among the KRAS tested, 11% (n = 328) harbored KRAS G12C. More KRAS G12C patients were women (67%), smokers (86%), had a high (≥50%) level of PD-L1 expression (54%), and more frequently received anti-PD-L1 treatment than any other group. From the date of the mutational test result, OS (7.1-7.3 months) was similar between the groups. OS from LOT1 (14.0 months) and LOT2 (10.8 months), and TTNT from LOT1 (6.9 months) and LOT2 (6.3 months) was numerically longer for the KRAS G12C mutated group compared to any other group. However, from LOT1 and LOT2, the OS and TTNT were comparable when stratifying the groups by PD-L1 expression level. Regardless of the mutational group, OS was markedly longer for patients with high PD-L1 expression. CONCLUSION: In patients diagnosed with advanced NSCLC after the implementation of anti-PD-1/L1 therapies, the survival in KRAS G12C mutated patients is comparable to patients with any KRAS mutation, Triple WT, and all NSCLC patients.

Healthcare resource utilization prior to suicide death or suicide attempt in patients with major depressive disorder-A Danish registry-based cohort study.

INTRODUCTION: Major depressive disorder (MDD) is associated with suicide events and with increased healthcare resource utilization (HRU). The aim was to analyze the pattern of HRU prior to death by suicide or suicide attempt in patients with MDD using national registries. METHODS: Danish adults with MDD, who died by suicide or had a first-time suicide attempt, were matched with MDD controls on age, sex, and MDD severity and analyzed for psychiatric and non-psychiatric hospital and private practitioner contacts, and prescriptions 1 year prior to the event. For individuals having a second suicide attempt, HRU prior to first and second suicide attempt was analyzed. RESULTS: Among 1061 individuals dying by suicide and 3759 individuals with suicide attempt, compared with their controls, the proportion with psychiatric hospitalization was more than 50% increased, mainly accounted for by acute contacts. The difference to the matched controls decreased with increasing MDD severity. Non-psychiatric HRU was increased as well. The proportion with psychiatric hospitalizations or ED visits was reduced prior to the second attempt compared with first attempt. CONCLUSION: Among individuals with MDD, psychiatric and non-psychiatric HRU was increased 1 year prior to suicide event. The proportion of individuals who had psychiatric HRU decreased from first to second suicide attempt.

Drug utilization of biologic therapy in Crohn's disease and ulcerative colitis: a population-based Danish cohort study 2015-2020.

OBJECTIVE: The aim of the study was to characterize the drug utilization and switch patterns of biological treatment of ulcerative colitis (UC) and Crohn's disease (CD). METHODS: Using Danish national registries, this nationwide study included individuals diagnosed with UC or CD, bio-naïve at the initiation of treatment with infliximab, adalimumab, vedolizumab, golimumab, or ustekinumab in 2015-2020. Hazard ratios of discontinuing the first treatment or switching to another biological treatment were explored using Cox regression. RESULTS: Among 2995 UC patients and 3028 CD patients, infliximab was used as a first-line biologic treatment in 89% of UC patients and 85% of CD patients, followed by adalimumab with 6%, vedolizumab with 3%, and golimumab with 1% for UC, and adalimumab with 12%, vedolizumab with 2%, and ustekinumab with 0.4% for CD.When comparing adalimumab as the first treatment series to infliximab, there was a higher risk of treatment discontinuation (excluding switch) among UC patients (hazard ratio: 2.02 [95% confidence interval: 1.57; 2.60]) and CD patients (1.85 [1.52; 2.24]). When comparing vedolizumab to infliximab, there was a lower risk of discontinuation for UC patients (0.51 [0.29-0.89]), and for CD patients, although not significantly (0.58 [0.32-1.03]). We observed no significant difference in the risk of switching to another biologic treatment for any of the biologics. CONCLUSION: More than 85% of UC and CD patients initiating biologic therapy had infliximab as their first-line biologic treatment, in accordance with official treatment guidelines. Future studies should explore the higher incidence of treatment discontinuation of adalimumab as the first treatment series.Key summarySeveral biologic therapies are available in the treatment of ulcerative colitis and Crohn's disease.Clinical guidelines stipulate that infliximab should be the first-line biologic therapy.Drug utilization studies comparing biologic therapies head-to-head are sparse.In Denmark, during 2015-2020 infliximab remained the most widely used biologic treatment, with adalimumab being second.One in four patients experienced more than one biologic during the study period.The risk of discontinuation of biologic treatment (and not starting a new biologic) was higher for initiators of adalimumab.Clinical and social background factors available from the registers could not account for the observed risk difference in discontinuation.

Genetic regulators of cytokine responses upon BCG vaccination in children from West Africa.

Genetic variation is a key factor influencing cytokine production capacity, but which genetic loci regulate cytokine production before and after vaccination, particularly in African population is unknown. Here, we aimed to identify single-nucleotide polymorphisms (SNPs) controlling cytokine responses after microbial stimulation in infants of West-African ancestry, comprising of low-birth-weight neonates randomized to bacillus Calmette-Guérin (BCG) vaccine-at-birth or to the usual delayed BCG. Genome-wide cytokine cytokine quantitative trait loci (cQTL) mapping revealed 12 independent loci, of which the LINC01082-LINC00917 locus influenced more than half of the cytokine-stimulation pairs assessed. Furthermore, nine distinct cQTLs were found among infants randomized to BCG. Functional validation confirmed that several complement genes affect cytokine response after BCG vaccination. We observed a limited overlap of common cQTLs between the West-African infants and cohorts of Western European individuals. These data reveal strong population-specific genetic effects on cytokine production and may indicate new opportunities for therapeutic intervention and vaccine development in African populations.

Healthcare resource utilization in patients with treatment-resistant depression-A Danish national registry study.

OBJECTIVES: To investigate healthcare resource utilization (HRU) and associated costs by depression severity and year of diagnosis among patients with treatment-resistant depression (TRD) in Denmark. METHODS: Including all adult patients with a first-time hospital contact for major depressive disorder (MDD) in 1996-2015, TRD patients were defined at the second shift in depression treatment (antidepressant medicine or electroconvulsive therapy) and matched 1:2 with non-TRD patients. The risk of utilization and amount of HRU and associated costs including medicine expenses 12 months after the TRD-defining date were reported, comparing TRD patients with non-TRD MDD patients. RESULTS: Identifying 25,321 TRD-patients matched with 50,638 non-TRD patients, the risk of psychiatric hospitalization following TRD diagnosis was 138.4% (95%-confidence interval: 128.3-149.0) higher for TRD patients than for non-TRD MDD patients. The number of hospital bed days and emergency department (ED) visits were also higher among TRD patients, with no significant difference for somatic HRU. Among patients who incurred healthcare costs, the associated HRU costs for TRD patients were 101.9% (97.5-106.4) higher overall, and 55.2% (50.9-59.6) higher for psychiatric services than those of non-TRD patients. The relative differences in costs for TRD-patients vs non-TRD patients were greater for patients with mild depression and tended to increase over the study period (1996-2015), particularly for acute hospitalizations and ED visits. LIMITATIONS: TRD was defined by prescription patterns besides ECT treatments. CONCLUSION: TRD was associated with increased psychiatric-related HRU. Particularly the difference in acute hospitalizations and ED visits between TRD and non-TRD patients increased over the study period.

Mapping Outcomes and Registries Used in Current Danish Pharmacoepidemiological Research.

Purpose: There is an increasing need for national and international pharmacoepidemiological studies based on high-quality real-world data of which the Danish registries are a valuable source. In lack of a complete overview of which data are used to assess real-world drug safety and effectiveness outcomes, we aimed to map the outcomes, data sources, and the reporting of outcome quality in recent pharmacoepidemiological studies. Methods: We conducted a systematic mapping review of pharmacoepidemiological studies based on Danish registries investigating drug safety and/or effectiveness, published in the period 2018-2019, identified in PubMed and Scopus. Extraction included: Anatomical Therapeutic Chemical level 2 code for drug exposures, outcomes, outcome data sources, and quality of outcomes. Results: Of the 210 included studies, 96% used outcomes categorized as Clinical, 4% utilized outcomes categorized as Society-related, 5% used outcomes categorized as Healthcare cost and utilization, and 3% of the studies applied outcomes categorized as Patient-reported in which the percentages are not mutually exclusive. Diagnosis (66%) and Mortality (38%) were the two most utilized subcategories among those categorized as Clinical outcomes. Danish Health Data Authority and Statistics Denmark registries were the most reported outcome data sources (90%). Ninety-six studies (46%) reported one or more quality parameters related to their outcomes of interest with accuracy/validity being the most reported parameter (22%). Conclusion: The Danish registries support a wide range of outcomes. Across therapeutic areas, most studies investigate traditional clinical outcomes of disease and mortality based on data from a small number of available registries. In contrast, clinical and biochemical databases, despite potentially offering outcomes with high responsiveness, and the high-quality social and healthcare cost registries were rarely used as outcome data sources.

Bacille Calmette-Guérin vaccine reprograms human neonatal lipid metabolism in vivo and in vitro.

Vaccines have generally been developed with limited insight into their molecular impact. While systems vaccinology enables characterization of mechanisms of action, these tools have yet to be applied to infants, who are at high risk of infection and receive the most vaccines. Bacille Calmette-Guérin (BCG) protects infants against disseminated tuberculosis (TB) and TB-unrelated infections via incompletely understood mechanisms. We employ mass-spectrometry-based metabolomics of blood plasma to profile BCG-induced infant responses in Guinea-Bissau in vivo and the US in vitro. BCG-induced lysophosphatidylcholines (LPCs) correlate with both TLR-agonist- and purified protein derivative (PPD, mycobacterial antigen)-induced blood cytokine production in vitro, raising the possibility that LPCs contribute to BCG immunogenicity. Analysis of an independent newborn cohort from The Gambia demonstrates shared vaccine-induced metabolites, such as phospholipids and sphingolipids. BCG-induced changes to the plasma lipidome and LPCs may contribute to its immunogenicity and inform the development of early life vaccines.

Non-specific effects of maternal and offspring rabies vaccination on mortality and antibiotic use in a Danish pig herd: A randomized trial.

INTRODUCTION: Human non-live vaccines have been associated with detrimental non-specific effects (NSE), particularly in females. A large trial found 2-fold increased overall mortality in girls receiving a new malaria vaccine compared to the rabies vaccine used as a coontrol; a beneficial NSE of the rabies vaccine was proposed. Conversely, in dogs increased mortality was seen in females but not males following rabies vaccination of puppies born to immunized mothers. We investigated NSE of non-live rabies vaccine in piglets and the potential modifying effect of maternal priming with rabies vaccine. METHODS: In a Danish herd of commercial rabies virus-free pigs, 575 pregnant sows (2-3 weeks before scheduled farrowing) and 5747 of their offspring (median 6-day-old) were allocated (1:1) to non-live rabies vaccine (Versiguard rabies vet) or no rabies vaccine. Outcomes were overall mortality and antibiotic treatment until departure from the nursery (approximately age 12 weeks/30 kgs). RESULTS: Until weaning, overall offspring mortality was 2.2% (127 piglets died, rabies vaccine: n = 69; control: n = 58), the proportion ratio (PR) being 1.19 (95% confidence interval: 0.84-1.68). Until end of follow-up, mortality was 4.1% (233, rabies vaccine: n = 115; control = 118, PR: 0.97 (0.76-1.25)). Prior sow rabies vaccination did not affect piglet mortality. For mortality as well as risk of antibiotic treatment before weaning, there was indication of a beneficial effect of rabies vaccine in female piglets, but a negative effect in (castrated) male piglets from rabies-naïve sows. Prior sow vaccination significantly modified the vaccine effect estimate in female piglets toward a detrimental effect of rabies vaccine on treatment risk. These effects had waned by 12 weeks of age. CONCLUSION: The study did not support the hypothesized beneficial NSE of rabies vaccine. Although under-powered for subgroup analyses, the study indicated effect modification by sex and maternal vaccination. Results could be different in a herd with higher mortality and infectious burden.

Treatment patterns in patients with treatment-resistant depression in Danish patients with major depressive disorder.

OBJECTIVE: To describe treatment patterns in patients with treatment-resistant depression (TRD) and major depressive disorder (MDD) stratified by depression severity and year of diagnosis. Patterns of treatment were also compared to country-specific guidelines. METHODS: All adults registered first time with a hospital contact due to MDD from 1996 through 2015 were identified and followed for all dispensed prescriptions of antidepressants, antipsychotics, lithium, initiation of electroconvulsive therapy (ECT), and psychotherapy in Danish registers 12 months before and after their hospital MDD diagnosis. TRD was characterized by two shifts in treatment. RESULTS: We identified 197,615 patients of whom 15% developed TRD. In total, 88% of patients started treatment with antidepressants or ECT. Selective serotonin reuptake inhibitors (SSRIs) were the most frequently used treatment during the study period and more than half (50.7%) of patients changed treatment at least once. Among patients with TRD, serotonin and noradrenaline reuptake inhibitors (SNRIs) were the most frequently used treatment (55.9%), and 37.0% initiated a new treatment the following year. SSRIs and SNRIs were part of most combinations of treatment, regardless of depression severity, year of diagnosis, or presence of TRD. CONCLUSION: 15% of patients met the criteria for TRD. Irrespective of patient characteristics and year of diagnosis, SSRIs and SNRIs are the most used treatments for depression, even after patients met the criteria for TRD. We confirm that guidelines for first treatment were followed for most patients diagnosed with MDD in Denmark, but for patients with TRD, choice of treatment was arbitrary.

BCG skin reactions by 2 months of age are associated with better survival in infancy: a prospective observational study from Guinea-Bissau.

INTRODUCTION: Receiving Bacille Calmette-Guérin (BCG)-Denmark vaccine at birth has been associated with ~40% reductions in all-cause neonatal mortality. We evaluated determinants of BCG skin reaction characteristics by age 2 months and tested the association with subsequent mortality. METHODS: Prospective observational study amalgamating five trials providing BCG-at-birth that were conducted between 2002 and 2018 in Guinea-Bissau. The reaction status and size were evaluated at home-visits by 2 months of age among 6012 neonates; mortality from 2 to 12 months was assessed at subsequent visits. Reaction determinants were evaluated by binomial regression providing risk ratios (RRs). In Cox-models providing adjusted mortality rate ratios (aMRRs), we assessed the association between (1) having a 2-month reaction (yes/no) and (2) reaction size tertiles and subsequent all-cause mortality risk. A subgroup had their BCG reaction evaluated and were bled at age 4 weeks; their samples underwent in vitro analysis for specific and non-specific cytokine responses. RESULTS: The BCG strain was the main determinant for developing a 2-month reaction and the reaction size: the BCG-Russia/BCG-Denmark RR for large-reaction was 0.38 (0.30-0.47) and the BCG-Russia/BCG-Japan RR was 0.61 (0.51-0.72). 5804 infants (96.5%) were reactors by age 2 months; 208 (3.5%) were non-reactors. The 2-12 months mortality risk was 4.8% (10/208) for non-reactors, 2.9% (64/2213) for small reactors, 1.8% (30/1710) for medium reactors and 0.8% (15/1881) for large reactors. The reactor/non-reactor aMRR was 0.49 (0.26-0.95) and there was a linear trend of decreasing mortality with increasing reaction size (p for trend <0.001). BCG reactors had higher 4-week specific and non-specific cytokine responses, responses that were highest among those with large reactions. CONCLUSION: Among BCG-vaccinated infants, having a BCG skin reaction by age 2 months was associated with markedly better survival, as was the reaction size. Our findings thus support that BCG has substantial effects on all-cause mortality. Emphasising at-birth vaccination with immunogenic BCG strains and revaccinating non-reactors and small reactors could have major public health benefits. TRIAL REGISTRATION NUMBERS: NCT00146302, NCT00168610, NCT00625482, NCT01989026 and NCT02447536.

Serum Perfluoroalkyl Substances, Vaccine Responses, and Morbidity in a Cohort of Guinea-Bissau Children.

BACKGROUND: Perfluoroalkyl substances (PFAS) are a group of widely used persistent chemicals with suspected immunotoxic effects. OBJECTIVES: The present study aimed to examine the association between infant PFAS exposure and antibody responses to measles vaccination as well as morbidity in a low-income country. METHODS: In a randomized controlled trial, children from Guinea-Bissau, West Africa, were followed from inclusion (4-7 months of age) through 2 years of age. Half the children received two measles vaccinations (at inclusion and at 9 months of age), and the other half received only one (at 9 months of age). In a subset of 237 children, six PFAS were quantified in serum at inclusion, and measles antibody concentrations were assessed at inclusion and at approximately 9 months and 2 years of age. At inclusion and at the 9-month visit, mothers were interviewed about infant morbidity. RESULTS: All but one child had detectable serum concentrations of all six PFAS, although levels were lower than seen elsewhere. A doubling in perfluorooctane sulfonic acid (PFOS) and perfluorodecanoic acid (PFDA) were associated with 21% (95% CI: 2, 37%) and 25% (95% CI: 1, 43%), respectively, lower measles antibody concentrations at the 9-month visit among the children who had received a measles vaccine at inclusion. Elevated serum PFAS concentrations were also associated with reduced prevaccination measles antibody concentrations and increased morbidity. DISCUSSION: The present study documents that PFAS exposure has reached West Africa and that infants show PFAS-associated increases in morbidity and decreases in measles-specific antibody concentrations before and after vaccination. These findings support the evidence on PFAS immunotoxicity at comparatively low serum concentrations. https://doi.org/10.1289/EHP6517.

Seasonal variation in the non-specific effects of BCG vaccination on neonatal mortality: three randomised controlled trials in Guinea-Bissau.

The BCG vaccine protects non-specifically against other diseases than tuberculosis. Three randomised controlled trials of early BCG in Guinea-Bissau found a 38% reduction in all-cause neonatal mortality. Little is known about the underlying mechanisms. In Guinea-Bissau, prevalent infectious diseases display distinct seasonality. Revisiting the three trials (>6500 infants) comparing early BCG versus no early BCG in low weight infants on all-cause neonatal mortality over 12 consecutive years, we explored the seasonal variation in BCG's effect on mortality. In a subgroup of participants, adaptive and innate cytokine responses were measured 4 weeks after randomisation. Consistently over the course of the three trials and 12 years, the effect of BCG on all-cause neonatal mortality was particularly beneficial when administered in November to January, coincident with peaking malaria infections. During these months, BCG was also associated with stronger proinflammatory responses to heterologous challenge. Recent studies have suggested a protective effect of BCG against malaria. BCG may also ameliorate immune-compromising fatal effects of placental malaria in the newborn.

Bacille Calmette-Guérin vaccination at birth and differential white blood cell count in infancy. A randomised clinical trial.

BACKGROUND: The Bacille Calmette-Guérin (BCG) vaccine against tuberculosis (TB) may have beneficial non-specific effects (NSEs) beyond the protection against TB. This may be related to modifications of the innate immune system. We investigated the effect of BCG at birth on differential white blood cell (WBC) count in healthy, Danish infants. METHOD: The Danish Calmette Study randomised newborns to BCG at birth (Danish strain 1331, Statens Serum Institut) or no intervention. A sub-group of infants had blood samples collected 4 days after randomisation (n = 161), and at age 3 months (n = 152) and 13 months (n = 300). We evaluated the effect of BCG on WBC differential count (total leucocytes, lymphocytes, monocytes, eosinophil, neutrophil and basophil granulocytes (109 cells/L)) measured in peripheral blood. RESULTS: Overall, we found no effect of BCG on differential WBC counts at any time point. CONCLUSION: BCG at birth did not affect WBC count in our cohort of healthy, Danish infants.

The Effect of Inactivated Mycobacterium Paratuberculosis Vaccine on the Response to a Heterologous Bacterial Challenge in Pigs.

Background: Vaccines may have non-specific effects, affecting resistance to heterologous pathogens. Veterinary vaccines have seldom been investigated for their non-specific effects. However, recent observational studies suggest that an inactivated paratuberculosis vaccine reduced all-cause mortality in goats and cattle. Aim: We tested if vaccination with a killed mycobacterial vaccine may have heterologous effects in swine (Sus domesticus), specifically on the pathogenic and clinical effects of a heterologous challenge with Actinobacillus pleuropneumoniae in young pigs. Methods: Newborn piglets were randomized to vaccination s.c. with the inactivated paratuberculosis vaccine Gudair (Zoetis Inc.) (n = 17) or no vaccine (n = 16). At 4-5 weeks after vaccination, all piglets were challenged intra-nasally with a high (Gudair: n = 8; control: n = 8) or a low (Gudair: n = 9; control: n = 8) dose of the gram-negative bacterium A. pleuropneumoniae causing acute porcine pleuropneumonia. The effect and severity of pathogen challenge was evaluated by measuring acute phase proteins C-reactive protein, haptoglobin and Porcine α1-acid glycoprotein, and by gross pathology 1 day post challenge. Specific and non-specific in vitro cytokine responses to vaccination were evaluated in whole blood before bacterial challenge. Results: The vaccine was immunogenic in the pigs as evidenced by increased IFN-γ responses to purified protein derivative of Mycobacterium paratuberculosis. However, Gudair vaccine did not affect IL-6 responses. The gross pathology of the lungs as well as the acute phase protein responses after the high A. pleuropneumoniae dose challenge was slightly increased in the vaccinated animals compared with controls, whereas this was not seen in the animals receiving the low-dose bacterial challenge. Conclusion: The inactivated paratuberculosis vaccine exacerbated the pathological and inflammatory effects of an experimental A. pleuropneumoniae infection in young pigs.

Recognition of microbial viability via TLR8 drives TFH cell differentiation and vaccine responses.

Live attenuated vaccines are generally highly efficacious and often superior to inactivated vaccines, yet the underlying mechanisms of this remain largely unclear. Here we identify recognition of microbial viability as a potent stimulus for follicular helper T cell (TFH cell) differentiation and vaccine responses. Antigen-presenting cells (APCs) distinguished viable bacteria from dead bacteria through Toll-like receptor 8 (TLR8)-dependent detection of bacterial RNA. In contrast to dead bacteria and other TLR ligands, live bacteria, bacterial RNA and synthetic TLR8 agonists induced a specific cytokine profile in human and porcine APCs, thereby promoting TFH cell differentiation. In domestic pigs, immunization with a live bacterial vaccine induced robust TFH cell and antibody responses, but immunization with its heat-killed counterpart did not. Finally, a hypermorphic TLR8 polymorphism was associated with protective immunity elicited by vaccination with bacillus Calmette-Guérin (BCG) in a human cohort. We have thus identified TLR8 as an important driver of TFH cell differentiation and a promising target for TFH cell-skewing vaccine adjuvants.