mRNA vaccines against SARS-CoV-2 are remarkably effective. Limited information exists about the incidence of adverse events following immunization (AEFI) with their use. We conducted a prospective observational study including data from 704,003 first-doses recipients; 6536 AEFI were reported, of whom 65.1% had at least one neurologic AEFI ( non-serious 99.6%). Thirty-three serious events were reported; 17 (51.5%) were neurologic (observed frequency, 2.4/100,000 doses). At the time of writing this report, 16/17 cases had been discharged without deaths. Our data suggest that the BNT162b2 mRNA COVID-19 vaccine is safe; its individual and societal benefits outweigh the low percentage of serious neurologic AEFI. This information should help to dissipate hesitancy towards this new vaccine platform.

Vaccines are the most effective strategy to mitigate the global impact of COVID-19. However, vaccine hesitancy is common, particularly among minorities. Guillain-Barré syndrome (GBS) is the most common autoimmune illness of the peripheral nervous system, occurring at an incidence of 1.1/100,000 worldwide. A causal link between mRNA vaccines and GBS has not been previously evaluated. We analyzed a cohort of 3,890,250 Hispanic/Latinx recipients of the BNT162b2 mRNA vaccine (613,780 of whom had already received both doses) for incident GBS occurring within 30 days from vaccine administration. Seven cases of GBS were detected among first-dose recipients, for an observed incidence of 0.18/100,000 administered doses during the prespecified timeframe of 30 days. No cases were reported after second-dose administration. Our data suggest that, among recipients of the BNT162b2 mRNA vaccine, GBS may occur at the expected community-based rate; however, this should be taken with caution as the current incidence of GBS among the unvaccinated population against COVID-19 is still undetermined. We hope that this preliminary data will increase the public perception of safety toward mRNA-based vaccines and reduce vaccine hesitancy.

Background The coronavirus disease 2019 (COVID-19) is a systemic entity that frequently implies neurologic features at presentation and complications during the disease course. We aimed to describe the characteristics and predictors for developing in-hospital neurologic manifestations in a large cohort of hospitalized patients with COVID-19 in Mexico City. Methods We analyzed records from consecutive adult patients hospitalized from March 15 to June 30, 2020, with moderate to severe COVID-19 confirmed by reverse transcription real-time polymerase chain reaction (rtRT-PCR) for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Neurologic syndromes were actively searched by a standardized structured questionnaire and physical examination, confirmed by neuroimaging, neurophysiology of laboratory analyses, as applicable. Results We studied 1,072 cases (65% men, mean age 53.2±13 years), 71 patients had pre-existing neurologic diseases (diabetic neuropathy: 17, epilepsy: 15, history of ischemic stroke: eight, migraine: six, multiple sclerosis: one, Parkinson disease: one), and 163 (15.2%) developed a new neurologic complication. Headache (41.7%), myalgia (38.5%), dysgeusia (8%), and anosmia (7%) were the most common neurologic symptoms at hospital presentation. Delirium (13.1%), objective limb weakness (5.1%), and delayed recovery of mental status after sedation withdrawal (2.5%), were the most common new neurologic syndromes. Age, headache at presentation, preexisting neurologic disease, invasive mechanical ventilation, and neutrophil/lymphocyte ratio ≥9 were independent predictors of new in-hospital neurologic complications. Conclusions Even after excluding initial clinical features and pre-existing comorbidities, new neurologic complications in hospitalized patients with COVID-19 are frequent and can be predicted from clinical information at hospital admission.

Background An intriguing feature recently unveiled in some COVID-19 patients is the “silent hypoxemia” phenomenon, which refers to the discrepancy of subjective well-being sensation while suffering hypoxia, manifested as the absence of dyspnea. Objective To describe the clinical characteristics and predictors of silent hypoxemia in hospitalized COVID-19 patients. Methods We conducted a prospective cohort study including consecutive hospitalized adult (≥ 18 years) patients with confirmed COVID-19 presenting to the emergency department with oxygen saturation (SpO2) ≤ 80% on room air from March 15 to June 30, 2020. We analyzed the characteristics, disease severity, and in-hospital outcomes of patients presenting with dyspnea and those without dyspnea (silent hypoxemia). Results We studied 470 cases (64.4% men; median age 55 years, interquartile range 46–64). There were 447 (95.1%) patients with dyspnea and 23 (4.9%) with silent hypoxemia. The demographic and clinical characteristics, comorbidities, laboratory and imaging findings, disease severity, and outcomes were similar between groups. Higher breathing and heart rates correlated significantly with lower SpO 2 in patients with dyspnea but not in those with silent hypoxemia. Independent predictors of silent hypoxemia were the presence of new-onset headache (OR 2.919, 95% CI 1.101–7.742; P = 0.031) and presenting to the emergency department within the first eight days after symptoms onset (OR 3.183, 95% CI 1.024–9.89; P = 0.045). Conclusions Patients with silent hypoxemia sought medical attention earlier and had new-onset headache more often. They were also likely to display lower hemodynamic compensatory responses to hypoxemia, which may underestimate the disease severity.

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.

BackgroundDiabetes affects approximately 250 million people in the world. Cardiovascular autonomic neuropathy is a common complication of diabetes that leads to severe postural hypotension, exercise intolerance, and increased incidence of silent myocardial infarction.ObjectiveTo determine the variability of heart rate (HR) and systolic blood pressure (SBP) in recently diagnosed diabetic patients.MethodsThe study included 30 patients with a diagnosis of type 2 diabetes of less than 2 years and 30 healthy controls. We used a Finapres® device to measure during five minutes beat-to-beat HR and blood pressure in three experimental conditions: supine position, standing position, and rhythmic breathing at 0.1 Hz. The results were analyzed in the time and frequency domains.ResultsIn the HR analysis, statistically significant differences were found in the time domain, specifically on short-term values such as standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), and number of pairs of successive NNs that differ by more than 50 ms (pNN50). In the BP analysis, there were no significant differences, but there was a sympathetic dominance in all three conditions. The baroreflex sensitivity (BRS) decreased in patients with early diabetes compared with healthy subjects during the standing maneuver.ConclusionsThere is a decrease in HR variability in patients with early type 2 diabetes. No changes were observed in the BP analysis in the supine position, but there were changes in BRS with the standing maneuver, probably due to sympathetic hyperactivity.

Supplemental data available from Dryad (Figure e-1. Example of a teleneurology consultation in a patient performing a virtual modified quantitative myasthenia gravis score;Table e-1. English version of the survey to assess the patient perception and satisfaction of our teleneurology program; Table e-2. Spanish version of the survey to assess the patient perception and satisfaction of our teleneurology program; Table e-3. Neurologic diagnoses treated in our teleneurology program; Table e-4. Patients responses to the survey to assess our teleneurology program; e-References)

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