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In the context of infectious diseases, the dynamic interplay between ever-changing host populations and viral biology demands a more flexible modeling approach than common fixed correlations. Embracing random-effects regression models allows for a nuanced understanding of the intricate ecological and evolutionary dynamics underlying complex phenomena, offering valuable insights into disease progression and transmission patterns. In this article, we employed a random-effects regression to model an observed decreasing median plasma viral load (pVL) among individuals with HIV in Mexico City during 2019-2021. We identified how these functional slope changes (i.e. random slopes by year) improved predictions of the observed pVL median changes between 2019 and 2021, leading us to hypothesize underlying ecological and evolutionary factors. Our analysis involved a dataset of pVL values from 7325 ART-naïve individuals living with HIV, accompanied by their associated clinical and viral molecular predictors. A conventional fixed-effects linear model revealed significant correlations between pVL and predictors that evolved over time. However, this fixed-effects model could not fully explain the reduction in median pVL; thus, prompting us to adopt random-effects models. After applying a random effects regression model-with random slopes and intercepts by year-, we observed potential "functional changes" within the local HIV viral population, highlighting the importance of ecological and evolutionary considerations in HIV dynamics: A notably stronger negative correlation emerged between HIV pVL and the CpG content in the pol gene, suggesting a changing immune landscape influenced by CpG-induced innate immune responses that could impact viral load dynamics. Our study underscores the significance of random effects models in capturing dynamic correlations and the crucial role of molecular characteristics like CpG content. By enriching our understanding of changing host-virus interactions and HIV progression, our findings contribute to the broader relevance of such models in infectious disease research. They shed light on the changing interplay between host and pathogen, driving us closer to more effective strategies for managing infectious diseases. SIGNIFICANCE OF THE STUDY: This study highlights a decreasing trend in median plasma viral loads among ART-naïve individuals living with HIV in Mexico City between 2019 and 2021. It uncovers various predictors significantly correlated with pVL, shedding light on the complex interplay between host-virus interactions and disease progression. By employing a random-slopes model, the researchers move beyond traditional fixed-effects models to better capture dynamic correlations and evolutionary changes in HIV dynamics. The discovery of a stronger negative correlation between pVL and CpG content in HIV-pol sequences suggests potential changes in the immune landscape and innate immune responses, opening avenues for further research into adaptive changes and responses to environmental shifts in the context of HIV infection. The study's emphasis on molecular characteristics as predictors of pVL adds valuable insights to epidemiological and evolutionary studies of viruses, providing new avenues for understanding and managing HIV infection at the population level.

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Flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV) are spread by mosquitoes and cause human disease and mortality in tropical areas. In contrast, Powassan virus (POWV), which causes severe neurologic illness, is a flavivirus transmitted by ticks in temperate regions of the Northern hemisphere. We find serologic neutralizing activity against POWV in individuals living in Mexico and Brazil. Monoclonal antibodies P002 and P003, which were derived from a resident of Mexico (where POWV is not reported), neutralize POWV lineage I by recognizing an epitope on the virus envelope domain III (EDIII) that is shared with a broad range of tick- and mosquito-borne flaviviruses. Our findings raise the possibility that POWV, or a flavivirus closely related to it, infects humans in the tropics.

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Despite abundant evidence correlating T cell CD38 expression and HIV infection pathogenesis, its role as a CD4T cell immunometabolic regulator remains unclear. We find that CD38's extracellular glycohydrolase activity restricts metabolic reprogramming after T cell receptor (TCR)-engaging stimulation in Jurkat T CD4 cells, together with functional responses, while reducing intracellular nicotinamide adenine dinucleotide and nicotinamide mononucleotide concentrations. Selective elimination of CD38's ectoenzyme function licenses them to decrease the oxygen consumption rate/extracellular acidification rate ratio upon TCR signaling and to increase cycling, proliferation, survival, and CD40L induction. Pharmacological inhibition of ecto-CD38 catalytic activity in TM cells from chronic HIV-infected patients rescued TCR-triggered responses, including differentiation and effector functions, while reverting abnormally increased basal glycolysis, cycling, and spontaneous proinflammatory cytokine production. Additionally, ecto-CD38 blockage normalized basal and TCR-induced mitochondrial morphofunctionality, while increasing respiratory capacity in cells from HIV+ patients and healthy individuals. Ectoenzyme CD38's immunometabolic restriction of TCR-involving stimulation is relevant to CD4T cell biology and to the deleterious effects of CD38 overexpression in HIV disease.

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ABSTRACT Certain open access publishers based on the article processing charges model have found it highly profitable to operate within a gray zone that encompasses both legitimate and predatory publishing practices. In this context, maximum profits can be obtained by adequate combinations of journal acceptance rates and elevated article processing charges. Considering that the gray zone can be particularly challenging to identify and that it poses risks for authors aiming to establish academic carreers, we believe it is important to provide a comprehensive description of it.

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Certain open access publishers based on the article processing charges model have found it highly profitable to operate within a gray zone that encompasses both legitimate and predatory publishing practices. In this context, maximum profits can be obtained by adequate combinations of journal acceptance rates and elevated article processing charges. Considering that the gray zone can be particularly challenging to identify and that it poses risks for authors aiming to establish academic carreers, we believe it is important to provide a comprehensive description of it.

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PURPOSE: To estimate the cost-effectiveness of adding a CDK4/6 inhibitor to standard endocrine therapy in the first-line setting for advanced HR+/HER2- breast cancer in postmenopausal and premenopausal women, from the perspective of the Mexican public healthcare system. METHODS: We used a partitioned survival model to simulate relevant health outcomes in a synthetic cohort of patients with breast cancer derived from the PALOMA-2, MONALEESA-2, MONARCH-3 trials for postmenopausal patients, and from the MONALEESA-7 study for premenopausal patients. Effectiveness was measured in life years gained. Cost-effectiveness is reported through incremental cost-effectiveness ratios (ICER). RESULTS: In postmenopausal patients, palbociclib led to an increase of 1.51 life years, ribociclib of 1.58 years, and abemaciclib of 1.75 years, compared to letrozole alone. The ICER was 36,648 USD, 32,422 USD, and 26,888 USD, respectively. In premenopausal patients, ribociclib led to an increase of 1.82 life years when added to goserelin and endocrine therapy, with an ICER of 44,579 USD. In the cost minimization analysis, for postmenopausal patients, ribociclib was the treatment with the highest costs due to follow-up requirements. CONCLUSION: Palbociclib, ribociclib, and abemaciclib demonstrated a significant increase in effectiveness in postmenopausal patients, and ribociclib in premenopausal patients, when added to standard endocrine therapy for patients with advanced HR+/HER2- breast cancer. At the national stablished willingness to pay, only the addition of abemaciclib to standard endocrine therapy in postmenopausal women would be considered cost-effective. However, differences on results between therapies for postmenopausal patients were not statistically significant.

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PURPOSE: Mutations in the Kirsten rat sarcoma viral (KRAS) oncogene constitute a significant driver of lung adenocarcinoma, present in 10-40% of patients, which exhibit heterogeneous clinical outcomes, mainly driven by concurrent genetic alterations. However, characterization of KRAS mutational subtypes and their impact on clinical outcomes in Latin America is limited. METHODS: A cohort study was conducted at the National Cancer Institute (INCan) of Mexico. Individuals with advance-staged of adenocarcinoma and KRAS mutations, detected by next-generation sequencing, having undergone at least one line of therapy were included for analysis. Clinical and pathological characteristics were retrieved from institutional database from June 2014 to March 2023. RESULTS: KRAS was identified in fifty-four (15.6%) of 346 patients, among which 50 cases were included for analysis. KRASG12D (n = 16, 32%) and KRASG12C (n = 16, 32%) represented the most prevalent subtypes. KRASG12D mutations were associated with female (p = 0.018), never smokers (p = 0.108), and concurrences with EGFR (25.0% vs. 17.6%, p = 0.124) and CDKN2A (18.8% vs. 14.7%, p = 0.157). KRASG12D patients showed a better ORR (66.6% vs. 30.0%; OR 4.66, 95% CI 1.23-17.60, p = 0.023) and on multivariate analysis was significantly associated with better PFS (HR 0.36, 95% CI 0.16-0.80; p = 0.012) and OS (HR 0.24, 95% CI 0.08-0.70; p = 0.009). CONCLUSIONS: To our knowledge, this study represents the first effort to comprehensively characterize the molecular heterogeneity of KRAS-mutant NSCLC in Latin American patients. Our data reinforce the current view that KRAS-mutated NSCLC is not a single oncogene-driven disease and emphasizes the prognostic impact of diverse molecular profiles in this genomically defined subset of NSCLC. Further validation is warranted in larger multicenter Latin American cohorts to confirm our findings.

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IMPORTANCE: We identify both canonical and novel human leukocyte antigen (HLA)-HIV associations, providing a first step toward improved understanding of HIV immune control among the understudied Honduras Mestizo population. Our results are relevant to understanding the protective or detrimental effects of HLA subtypes in Latin America because their unique HLA diversity poses challenges for designing vaccines against HIV and interpreting results from such vaccine trials. Likewise, the description of the HLA profile in an understudied population that shows a unique HLA immunogenetic background is not only relevant for HIV immunology but also relevant in population genetics, molecular anthropology, susceptibility to other infections, autoimmune diseases, and allograft transplantation.

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Introduction: Our understanding of HIV-associated gut microbial dysbiosis in children perinatally-infected with HIV (CLWH) lags behind that of adults living with HIV. Childhood represents a critical window for the gut microbiota. Any disturbances, including prolonged exposure to HIV, antiretroviral drugs, and antibiotics are likely to have a significant impact on long-term health, resulting in a less resilient gut microbiome. The objective of our study was to characterize the gut microbiota in CLWH, and compare it with HIV-unexposed and -uninfected children. Methods: We enrolled 31 children aged 3 to 15 years; 15 were CLWH and 16 were HUU. We assessed dietary patterns and quality; quantified soluble and cellular markers of HIV disease progression by flow cytometry, enzyme-linked immunosorbent and multiplex-bead assays, and profiled the gut microbiota by 16S rRNA sequencing. We explored relationships between the gut microbiota, antibiotic exposure, dietary habits, soluble and cellular markers and host metadata. Results: Children had a Western-type diet, their median health eating index score was 67.06 (interquartile range 58.76-74.66). We found no discernable impact of HIV on the gut microbiota. Alpha diversity metrics did not differ between CLWH and HUU. Sex impacted the gut microbiota (R-squared= 0.052, PERMANOVA p=0.024). Male children had higher microbial richness compared with female children. Two taxa were found to discriminate female from male children independently from HIV status: Firmicutes for males, and Bacteroides for females. Markers of HIV disease progression were comparable between CLWH and HUU, except for the frequency of exhausted CD4+ T cells (PD-1+) which was increased in CLWH (p=0.0024 after adjusting for confounders). Both the frequency of exhausted CD4+ and activated CD4+ T cells (CD38+ HLADR+) correlated positively with the relative abundance of Proteobacteria (rho=0.568. false discovery rate (FDR)-adjusted p= 0.029, and rho=0.62, FDR-adjusted p=0.0126, respectively). Conclusion: The gut microbiota of CLWH appears similar to that of HUU, and most markers of HIV disease progression are normalized with long-term ART, suggesting a beneficial effect of the latter on the gut microbial ecology. The relationship between exhausted and activated CD4+ T cells and Proteobacteria suggests a connection between the gut microbiome, and premature aging in CLWH.

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OBJECTIVES: Vaccination has been effective in ameliorating the impact of COVID-19. Here, we report vaccine effectiveness (VE) of the nationally available COVID-19 vaccines in Mexico. METHODS: Retrospective analysis of a COVID-19 surveillance system to assess the VE of the BNT162b2, messenger RNA (mRNA)-12732, Gam-COVID-Vac, Ad5-nCoV, Ad26.COV2.S, ChAdOx1, and CoronaVac vaccines against SARS-CoV-2 infection, COVID-19 hospitalization, and death in Mexico. The VE was estimated using time-varying Cox proportional hazard models in vaccinated and unvaccinated adults, adjusted for age, sex, and comorbidities. VE was also estimated for adults with diabetes, aged ≥60 years, and comparing the predominance of SARS-CoV-2 variants B.1.1.519 and B.1.617.2. RESULTS: We assessed 793,487 vaccinated and 4,792,338 unvaccinated adults between December 24, 2020 and September 27, 2021. The VE against SARS-CoV-2 infection was the highest for fully vaccinated individuals with mRNA-12732 (91.5%, 95% confidence interval [CI] 90.3-92.4) and Ad26.COV2.S (82.2%, 95% CI 81.4-82.9); for COVID-19 hospitalization, BNT162b2 (84.3%, 95% CI 83.6-84.9) and Gam-COVID-Vac (81.4% 95% CI 79.5-83.1), and for mortality, BNT162b2 (89.8%, 95% CI 89.2-90.2) and mRNA-12732 (93.5%, 95% CI 86.0-97.0). The VE decreased for all vaccines in adults aged ≥60 years, people with diabetes, and periods of Delta variant predominance. CONCLUSION: All the vaccines implemented in Mexico were effective against SARS-CoV-2 infection, COVID-19 hospitalization, and death. Mass vaccination with multiple vaccines is useful to maximize vaccination coverage.

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Double-negative (DN) T cells represent a small and phenotypically heterogeneous population that display regulatory functions. In HIV infection, DN T cells are decreased in peripheral blood and have been negatively associated with T cell activation. This study was aimed at describing the dynamics and phenotypic characteristics of DN T cells in peripheral blood of people living with HIV (PLHIV) before and after antiretroviral therapy (ART) initiation. We included 41 newly diagnosed, ART-naive individuals with advanced HIV infection, who were followed up for 6 months after ART initiation. The control group included 34 people without HIV (PWHIV), on preexposure prophylaxis for HIV infection. DN T cells in peripheral blood were characterized by flow cytometry. The absolute counts of DN T cells were lower in PLHIV than in PWHIV (p = 0.0223), and were particularly low in individuals with advanced HIV disease (p = 0.0311). Activation of DN T cells before ART initiation was directly associated with viral load (VL) (p = 0.0081, r = 0.4083) and inversely associated with CD4+ T cell counts (p = 0.0004, r = -0.4041). Compared with PWHIV, DN T cells of PLHIV expressed higher levels of CD57 (p = 0.0019), Ki67 (p = 0.0065), PD-1 (p = 0.0187), and CD38/HLA-DR (p < 0.0001). After 6 months on ART, expression of Ki67, PD-1, and CD38/HLA-DR on DN T cells returned to similar levels to those observed in PWHIV (p > 0.05 in all cases). However, expression of CD57 decreased only in individuals that start ART with high VL (p = 0.0127). DN T cell counts are decreased in HIV infection. Low DN T cell counts remained despite ART-induced immune reconstitution and viremia control. DN T cell phenotype is altered during chronic untreated infection with a high proportion of proliferating, activated, exhausted, and senescent cells. Most markers return to levels similar to those observed in PWHIV after ART. The impact of altered phenotype of DN T and their regulatory functions warrants further exploration.

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Background: Human monkeypox, a zoonosis historically endemic to West and South Africa, has led to a worldwide outbreak driven by human-to-human transmission resulting in an international public health emergency. Endemic and outbreak monkeypox cases may differ in their affected populations, clinical features, and outcomes. Thus, profiling cases of the current monkeypox outbreak worldwide is crucial. Methods: We performed a nationwide observational surveillance-based study from May 24 to September 5, 2022. Patients that met the operational clinical definition of monkeypox or symptomatic close contacts of confirmed cases were tested by real-time polymerase chain reaction. Clinical data were collected with a standardized case-report form. We report epidemiologic, sociodemographic, and clinical characteristics of confirmed cases. Findings: Five-hundred and sixty-five human monkeypox confirmed cases were analysed; 97.2% were men, of whom 59.5% identified as men who have sex with men, and 54.5% had human immunodeficiency virus infection. The median age was 34 years. All patients but one had rash (99.8%), 78.9% had fever, and 47.8% reported myalgia. The anogenital area was the most commonly affected one by rash (49.6%), and proctitis occurred in 6.2% of patients. Six patients required hospitalization, of which one died due to causes unrelated to monkeypox. Interpretation: The 2022 monkeypox outbreak in Mexico is mainly driven by middle-aged men who have sex with men, of which a large proportion are persons who live with human immunodeficiency virus infection. Clinical features such as the high proportion of anogenital lesions suggest sexual contact is a pivotal transmission mechanism in this outbreak. Funding: This research was supported by grant A1-S-18342 from Consejo Nacional de Ciencia y Tecnología (CONACyT), Mexico (to S.I.V.-F.).

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Background: Human immunodeficiency virus drug resistance (HIVDR) can negatively impact the effectiveness of antiretroviral therapy (ART). We aimed to estimate the prevalence of pretreatment HIVDR (PDR) among ART initiators and the prevalence of viral load (VL) suppression and acquired HIVDR among individuals receiving ART for 12 ± 3 months (ADR12) and ≥48 months (ADR48) in El Salvador. Methods: Nationally representative cross-sectional PDR, ADR12 and ADR48 surveys were conducted among adults with HIV from October 2018 to August 2019, following World Health Organization-recommended methods. Demographic and clinic data and blood specimens were collected. Results: Two hundred sixty participants were enrolled in the PDR survey, 230 in ADR12 and 425 in ADR48. Twenty-seven percent (95% confidence interval [CI], 17.1%-39.9%) of ART initiators had PDR to efavirenz or nevirapine. The prevalence of VL suppression was 88.8% (95% CI, 83.1%-92.8%) in ADR12 and 80.5% (95% CI, 76.6%-84.0%) in ADR48 surveys. Among people with HIV receiving a first-line nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART regimens and with unsuppressed VL, the prevalence of ADR to efavirenz or nevirapine was 72.0% (95% CI, 32.3%-93.3%) and 95.0% (68.5%-99.4%) in the ADR12 and ADR28 surveys, respectively. ADR12 to boosted protease inhibitors (PI/r) or integrase strand transfer inhibitors (INSTIs) was not observed. ADR48 was 1.3% (95% CI, 0.2%-9.6%) and 2.1% (0.3%-13.7%), respectively. Conclusions: Programmatic improvements in ART delivery are urgently needed in El Salvador to address the high levels of resistance to efavirenz or nevirapine among ART initiators and the low VL suppression prevalence among individuals on treatment.

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BACKGROUND: Despite the high number of vaccines administered against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide, the information on the psychological/psychiatric adverse events following immunization (AEFI) with these newly developed vaccines remains scarce. OBJECTIVE: To describe the frequency of psychological/psychiatric symptoms among recipients of five different anti-SARS-CoV-2 vaccines and to explore the factors associated with their development reported in the nationwide Mexican registry of AEFI against SARS-CoV-2. METHODS: Descriptive study of all the psychological/psychiatric symptoms, including anxiety, panic attacks, insomnia, and agitation reported to the Mexican Epidemiological Surveillance System from 21 December 2020 to 27 April 2021, among adult (≥18 years old) recipients of 7,812,845 doses of BNT162b2, ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, or CoronaVac. The factors associated with their development are determined by multivariate regression analysis. RESULTS: There were 19,163 AEFI reports during the study period; amongst them, 191 (1%) patients had psychological/psychiatric symptoms (median age of 41 years, interquartile range of 32-54; 149 [78%] women) for an observed incidence of 2.44 cases per 100,000 administered doses (95% confidence interval [CI] 2.12-2.82), 72.8% of psychiatric AEFIs were reported among recipients of BNT162b2. The median time from vaccination to symptom onset was 35 min (interquartile range: 10-720). Overall, the most common psychological/psychiatric symptoms were anxiety in 129 (67.5%) patients, panic attacks in 30 (15.7%), insomnia in 25 (13%), and agitation in 11 (5.7%). After adjusting for the confounding factors, the odds for developing psychological/psychiatric symptoms were higher for those concurrently reporting syncope (odds ratio [OR]: 4.73, 95% CI: 1.68-13.33); palpitations (OR: 2.47, 95% CI: 1.65-3.70), and dizziness (OR: 1.59, 95% CI: 1.10-2.28). CONCLUSION: In our population, psychological/psychiatric symptoms were extremely infrequent AEFIs. No severe psychiatric AEFIs were reported. Immunization stress-related responses might explain most of the detected cases.

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The COVID-19 pandemic led to the development and emergency approval of an array of effective vaccines against SARS-CoV-2. Given the relatively small number of patients included in vaccine trials, postapproval epidemiological surveillance is crucial to detect infrequent vaccine-related adverse events. We conducted a nationwide retrospective descriptive study evaluating the incidence of seizures among recipients of SARS-CoV-2 vaccines in Mexico from December 24, 2020 (date of administration of first doses nationwide) to October 29, 2021. Among 81 916 351 doses of any vaccine that were administered, we documented seizures in 53 patients, of which 31 (60%) were new onset seizures. The incidence rate of seizures per million doses was highest for mRNA-1273 (Moderna) with 2.73 per million, followed by BNT162b2 (Pfizer-BioNTech) with 1.02 per million, and Ad5-nCoV (CanSino) with 1.01 per million. Thus, we found that seizures following SARS-CoV-2 vaccination are exceedingly rare events.

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BACKGROUND: Information on anaphylaxis among recipients of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains scarce. OBJECTIVE: To identify the observed incidence of anaphylaxis in recipients of different anti-SARS-CoV-2 vaccines. METHODS: A nationwide observational study among recipients of 61,414,803 doses of seven different anti-SARS-CoV-2 vaccines, describing the incidence and characteristics of adult patients (age ≥ 18 years) who developed anaphylaxis as an adverse event following immunization (AEFI) against SARS-CoV-2 vaccines between December 24, 2020, and October 15, 2021, in Mexico. RESULTS: Sixty-six patients developed anaphylaxis as an AEFI, for an overall observed incidence of 1.07 cases per 1,000,000 (95% CI 0.84-1.37) administered doses. Eighty-six percent of the patients were female, consistent with previous reports of AEFI to COVID-19 vaccines. mRNA-based vaccine recipients had the highest frequency of anaphylaxis, followed by adenovirus-vectored vaccines and inactivated virus recipients, with an observed incidence of 2.5, 0.7, and 0.2 cases per 1,000,000 doses administered, respectively. Only 46% of the patients received correct treatment with epinephrine as the first-line treatment through the appropriate route and dose. We detected one case of anaphylactic reaction-related death occurring 5 min following immunization with ChAdOx1 nCov-19 for a mortality rate of 1.5% among those who developed this AEFI. CONCLUSIONS: In our population, anaphylactic reactions were infrequent. Our study provides further evidence supporting the security of these newly developed vaccines.

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Ear, nose, and throat (ENT) conditions are prevalent in people living with HIV (PLWH) and occur at all strata of CD4 counts and despite antiretroviral therapy (ART). ENT conditions are underreported in PLWH. Also, little is known about the adenotonsillar microbiota and its relation to resident adaptive and innate immune cells. To bridge this gap, we characterized immune cell populations and the bacterial microbiota of two anatomical sites (adenoids, tonsils) and the oral cavity. Adenoids and tonsils were obtained from PLWH (n = 23) and HIV-seronegative individuals (SN, n = 16) after nasal surgery and tonsillectomy and processed for flow cytometry. Nasopharyngeal, oropharyngeal swabs, and oral rinses were collected prior to surgery for 16S sequencing. Wilcoxon rank sum test, principal coordinate analysis, permutational multivariate analysis of variance, and linear discriminant analysis (LEfSe) were used to assess differences between PLWH and SN. Spearman's correlations were performed to explore interactions between the bacteriome and mucosal immune cells. Of the 39 individuals included, 30 (77%) were men; the median age was 32 years. All PLWH were on ART, with a median CD4 of 723 cells. ENT conditions were classified as inflammatory or obstructive, with no differences observed between PLWH and SN. PLWH had higher frequencies of activated CD4+ and CD8+ T cells, increased T helper (Th)1 and decreased Th2 cells; no differences were observed for B cells and innate immune cells. Alpha diversity was comparable between PLWH and SN at all 3 anatomical sites (adenoids, tonsils, and oral cavity). The impact of HIV infection on the bacterial community structure at each site, as determined by Permutational multivariate analysis of variance, was minor and not significant. Two discriminant genera were identified in adenoids using LEfSe: Staphylococcus for PLWH and Corynebacterium for SN. No discriminant genera were identified in the oropharynx and oral cavity. Niche-specific differences in microbial diversity and communities were observed. PLWH shared less of a core microbiota than SN. In the oropharynx, correlation analysis revealed that Th17 cells were inversely correlated with bacterial richness and diversity, Filifactor, Actinomyces and Treponema; and positively correlated with Streptococcus. Our study contributes toward understanding the role of the adenotonsillar microbiota in the pathophysiology of ENT conditions.

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BACKGROUND AND PURPOSE: Information on Guillain-Barré syndrome (GBS) as an adverse event following immunization (AEFI) against SARS-CoV-2 remains scarce. We aimed to report GBS incidence as an AEFI among adult (≥18 years) recipients of 81,842,426 doses of seven anti-SARS-CoV-2 vaccines between December 24, 2020, and October 29, 2021, in Mexico. METHODS: Cases were retrospectively collected through passive epidemiological surveillance. The overall observed incidence was calculated according to the total number of administered doses. Vaccines were analyzed individually and by vector as mRNA-based (mRNA-1273 and BNT162b2), adenovirus-vectored (ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, and Ad26.COV2-S), and inactivated whole-virion-vectored (CoronaVac) vaccines. RESULTS: We identified 97 patients (52 males [53.6%]; median [interquartile range] age 44 [33-60] years), for an overall observed incidence of 1.19/1,000,000 doses (95% confidence interval [CI] 0.97-1.45), with incidence higher among Ad26.COV2-S (3.86/1,000,000 doses, 95% CI 1.50-9.93) and BNT162b2 recipients (1.92/1,00,000 doses, 95% CI 1.36-2.71). The interval (interquartile range) from vaccination to GBS symptom onset was 10 (3-17) days. Preceding diarrhea was reported in 21 patients (21.6%) and mild COVID-19 in four more (4.1%). Only 18 patients were tested for Campylobacter jejuni (positive in 16 [88.9%]). Electrophysiological examinations were performed in 76 patients (78.4%; axonal in 46 [60.5%] and demyelinating in 25 [32.8%]); variants were similar across the platforms. On admission, 91.8% had a GBS disability score ≥3. Seventy-five patients (77.3%) received intravenous immunoglobulin, received seven plasma exchange (7.2%), and 15 (15.5%) were treated conservatively. Ten patients (10.3%) died, and 79.1% of survivors were unable to walk independently. CONCLUSIONS: Guillain-Barré syndrome was an extremely infrequent AEFI against SARS-CoV-2. The protection provided by these vaccines outweighs the risk of developing GBS.

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Evolutionary analyses of viral sequences can provide insights into transmission dynamics, which in turn can optimize prevention interventions. Here, we characterized the dynamics of HIV transmission within the Mexico City metropolitan area. HIV pol sequences from persons recently diagnosed at the largest HIV clinic in Mexico City (between 2016 and 2021) were annotated with demographic/geographic metadata. A multistep phylogenetic approach was applied to identify putative transmission clades. A data set of publicly available sequences was used to assess international introductions. Clades were analyzed with a discrete phylogeographic model to evaluate the timing and intensity of HIV introductions and transmission dynamics among municipalities in the region. A total of 6,802 sequences across 96 municipalities (5,192 from Mexico City and 1,610 from the neighboring State of Mexico) were included (93.6% cisgender men, 5.0% cisgender women, and 1.3% transgender women); 3,971 of these sequences formed 1,206 clusters, involving 78 municipalities, including 89 clusters of ≥10 sequences. Discrete phylogeographic analysis revealed (i) 1,032 viral introductions into the region, over one-half of which were from the United States, and (ii) 354 migration events between municipalities with high support (adjusted Bayes factor of ≥3). The most frequent viral migrations occurred between northern municipalities within Mexico City, i.e., Cuauhtémoc to Iztapalapa (5.2% of events), Iztapalapa to Gustavo A. Madero (5.4%), and Gustavo A. Madero to Cuauhtémoc (6.5%). Our analysis illustrates the complexity of HIV transmission within the Mexico City metropolitan area but also identifies a spatially active transmission area involving a few municipalities in the north of the city, where targeted interventions could have a more pronounced effect on the entire regional epidemic. IMPORTANCE Phylogeographic investigation of the Mexico City HIV epidemic illustrates the complexity of HIV transmission in the region. An active transmission area involving a few municipalities in the north of the city, with transmission links throughout the region, is identified and could be a location where targeted interventions could have a more pronounced effect on the entire regional epidemic, compared with those dispersed in other manners.

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