Risk of Ischemic Stroke after COVID-19 Bivalent Booster Vaccination in an Integrated Health System (preprint)

Abstract: Purpose: What is the absolute occurrence of ischemic stroke and transient ischemic attack after a COVID-19 bivalent vaccination? Methods: We conducted a retrospective cohort study of Kaiser Permanente Northwest (KPNW) patients 18 years and older who were vaccinated with either the Pfizer or Moderna formulation of the COVID19 bivalent vaccine between September 1, 2022 and March 1st 2023. Patients were included in the study if they had KP membership at the time of vaccination and through the 21-day follow up period. We replicated the Vaccine Safety Datalink (VSD) rapid cycle analysis methodology and searched for possible cases of ischemic stroke or TIA in the 21 days following vaccination using ICD10CM diagnosis codes in both the primary position and any position. We waited 90 days from the end of the follow up (March 21, 2023) for complete non KP data accrual before analyzing the data to account for the lag in processing outside hospital insurance claims. Two physicians adjudicated possible cases by reviewing the clinical notes in the electronic health record. The analyses were stratified by age 65 years and older to allow for comparisons with VSDs reporting at the Advisory Committee on Immunization Practices (ACIP) meeting of incidence of ischemic stroke or TIA (VSD reported incidence; 24.6 cases of ischemic stroke or TIA per 100,000 patients vaccinated). Results: The incidence of ischemic stroke or TIA was 34.3 per 100,000 (95% CI, 17.7 to 59.9) in patients 65 years or older who received the bivalent Pfizer vaccine, based on a diagnosis code in the primary position of the emergency department or hospital discharge. The incidence increased to 45.7 per 100,000 (95% CI 26.1 to 74.2) when we expanded the search to a diagnosis in any position and did not adjudicate to confirm. However, most of those additional apparent stroke or TIA diagnoses were false-positive diagnoses based on physicians adjudications. Estimating the incidence based on the primary position agreed closely with estimating the incidence based on any position and physician adjudication: 37.1 per 100,000 (95% CI 19.8 to 63.5). Seventy-nine percent of the ischemic stroke cases were admitted to hospitals that are not owned by the integrated delivery system. Conclusion: We identified a 50% increase in the incidence of ischemic stroke per 100,000 patients ages 65 and older vaccinated with the Pfizer bivalent vaccine, compared to the data presented by the VSD. Seventy-nine percent of the ischemic stroke cases were admitted to hospitals that are not owned by the integrated delivery system and a delay in processing outside hospital insurance claims was likely responsible for the discrepancy in case ascertainment of ischemic stroke. Physician adjudication of all cases in this study allowed accurate absolute incidence estimates of stroke per 100,000 vaccine recipients and is helpful in calculation of net benefit for policy recommendations and shared decision-making.

Changes in uptake of stool-based colorectal cancer screening during the Covid-19 pandemic.

PURPOSE: Colorectal cancer (CRC) screening is underutilized and endoscopic colon screening includes a number of barriers that were exacerbated by the Covid-19 pandemic. At-home stool-based screening (SBS) increased during the pandemic and potentially reached eligible adults hesitant to be screened by endoscopy. The purpose of this analysis was to examine the change in uptake of SBS during the pandemic among adults not screened within guidelines by endoscopy. METHODS: We used data from the 2019 and 2021 National Health Interview Surveys to estimate uptake of SBS among adults aged 50-75 years, without a previous diagnosis of CRC and without guideline-concordant endoscopic screening. We also examined provider recommendations for screening tests. To examine if changes in uptake differed during the pandemic by demographic and health characteristics, we combined survey years and ran logistic regression models with an interaction term for each factor and survey year. RESULTS: In our study population, SBS increased 74% overall from 2019 to 2021 (8.7% to 15.1%; p < 0.001), with the largest percent increase among those aged 50-52 years (3.5% to 9.9%; p < 0.001). Among those aged 50-52 years, the ratio of endoscopy to SBS changed from 83%/17% in 2019 to 55%/45% in 2021. Cologuard was the only screening test where recommendations by healthcare providers significantly increased from 2019 (10.6% to 16.1%; p = 0.002). CONCLUSIONS: Use and recommendations for SBS increased substantially during the pandemic. Increased awareness among patients could potentially improve future CRC screening rates if uptake of SBS occurs among those unable or unwilling to be screened by endoscopy.

Dysfunctional breathing induces vocal cord dysfunction following COVID-19 infection

Introduction/Aim: SARS-CoV-2 (COVID-19) has affected over 60 million people world-wide. In most cases symptoms are mild, however some people have ongoing symptoms lasting longer known as 'long COVID'. Exertional breathlessness is a common complaint in these patients. Dysfunctional breathing (DB) and vocal cord dysfunction (VCD) are two underappreciated causes of breathlessness. We hypothesized that in individuals who had experienced COVID-19, dysfunctional breathing could give rise to VCD. Method(s): Nine convenience-sampled participants with confirmed COVID-19 infection were included following resolution of the acute illness. Vocal cords movements were visualised via continuous laryngoscopy. Hyperventilation was employed as a surrogate for DB, using a standard protocol of 40 breathes per minute (bpm). Participants breathed through a flow sensor with concomitant laryngoscopy, and we monitored hyperventilation, gas exchange measurements and laryngeal movements. After 12-weeks patients returned for repeat hyperventilation testing. Result(s): The nine participants consisted of five females and four males, age range 24-66 years. Three of the nine participants developed classic inspiratory VCD during hyperventilation. Patients with VCD were female, younger (<45), reported significantly reduced exercise tolerance post infection and had been physically very active prior to COVID infection. In two participants VCD associated with hyperventilation had resolved on laryngoscopy at 12-weeks. In these two participants who had VCD, breathlessness and reduced exercise tolerance resolved at 12-weeks following laryngeal retraining. In one person evidence of VCD and reduced exercise tolerance persisted post 12-weeks review. Conclusion(s): This study provides the first evidence that COVID-19 may facilitate VCD via DB, causing unexplained breathlessness. Our findings suggest that this disease process may be implicated in 'long COVID' and provide a rationale for therapies such as breathing and laryngeal retraining.

Etiology of Acute Febrile Illness in the Peruvian Amazon as determined by modular formatted quantitative PCR: A Protocol for RIVERA, a Health Facility-Based Case-Control Study.

Background : The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. Methods : A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. Discussion : The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 hours and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific, prevalent pathogens as a cause of acute illness. Study Registration: Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.

Bringing rehabilitation home with an e-health platform to treat stroke patients: study protocol of a randomized clinical trial (RGS@home).

BACKGROUND: There is a pressing need for scalable healthcare solutions and a shift in the rehabilitation paradigm from hospitals to homes to tackle the increase in stroke incidence while reducing the practical and economic burden for patients, hospitals, and society. Digital health technologies can contribute to addressing this challenge; however, little is known about their effectiveness in at-home settings. In response, we have designed the RGS@home study to investigate the effectiveness, acceptance, and cost of a deep tech solution called the Rehabilitation Gaming System (RGS). RGS is a cloud-based system for delivering AI-enhanced rehabilitation using virtual reality, motion capture, and wearables that can be used in the hospital and at home. The core principles of the brain theory-based RGS intervention are to deliver rehabilitation exercises in the form of embodied, goal-oriented, and task-specific action. METHODS: The RGS@home study is a randomized longitudinal clinical trial designed to assess whether the combination of the RGS intervention with standard care is superior to standard care alone for the functional recovery of stroke patients at the hospital and at home. The study is conducted in collaboration with hospitals in Spain, Sweden, and France and includes inpatients and outpatients at subacute and chronic stages post-stroke. The intervention duration is 3 months with assessment at baseline and after 3, 6, and 12 months. The impact of RGS is evaluated in terms of quality of life measurements, usability, and acceptance using standardized clinical scales, together with health economic analysis. So far, one-third of the patients expected to participate in the study have been recruited (N = 90, mean age 60, days after stroke ≥ 30 days). The trial will end in July 2023. DISCUSSION: We predict an improvement in the patients' recovery, high acceptance, and reduced costs due to a soft landing from the clinic to home rehabilitation. In addition, the data provided will allow us to assess whether the prescription of therapy at home can counteract deterioration and improve quality of life while also identifying new standards for online and remote assessment, diagnostics, and intervention across European hospitals. TRIAL REGISTRATION: C linicalTrials.gov NCT04620707. Registered on November 3, 2020.

Teachers' experiences of emergency remote schooling during the pandemic: Drivers for student and teacher wellbeing

This article discusses findings from a recent survey (n = 297) of teachers' views of both their own and their students' experiences during the 2021 enforced emergency remote schooling period occurring in New South Wales Australia, due to the COVID-19 pandemic. The quantitative analysis reported here explores teachers' views regarding teaching and learning during this challenging period. It identifies three latent constructs, learning, assessment, and interaction, and then uses structural equation modelling to identify the perceived impact of these constructs on student and teacher wellbeing. The remote schooling period had a significant negative impact for teachers and their students across a range of elements of teaching and learning, as well as wellbeing. Student learning experiences and their peer interactions were found to be strong predictors of students' wellbeing outcomes. Assessment design and teachers' feedback to students were significant in predicting levels of teacher wellbeing. Future research directions are also provided. [ FROM AUTHOR] Copyright of Australian Journal of Education (Sage Publications Ltd.) is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Inequality and Irony: Barriers Associated with Missed Palliative Care Telemedicine Visits (TH106C)

Outcomes: 1. Determine factors associated with missed palliative care telemedicine visits, particularly those related to human differences, social identities, and social groups. 2. Utilize findings to stimulate initiatives that may promote equal opportunities in accessing palliative care telemedicine visits. Background(s): The COVID-19 pandemic accelerated the adoption of telemedicine in healthcare. Due to restrictions on in-person medical appointments, it was embraced by patients, providers, and payors and found its place in palliative care. While it showed efficiencies in healthcare delivery, telemedicine also brought about inequalities affecting the socioeconomically disadvantaged. The study aimed to identify factors associated with missed palliative care telemedicine visits. Method(s): This was a retrospective review of telemedicine visits between April 1, 2020, and March 31, 2021, at a palliative care clinic based in an academic medical center's cancer institute. Demographics, diagnosis and treatment, medical insurance, and enrollment in MyChartTM (online tool for patients to access their medical records) were recorded. Residency in community outreach zones (COZ), ZIP code clusters known for healthcare underutilization, was noted. Missed visits, either canceled or "no show," were analyzed;patients with at least three scheduled visits and missed at least 50% were considered pattern miss. Result(s): Of 1,225 scheduled telemedicine visits, there were 802 completed, 309 canceled, and 114 "no shows." Among 505 unique patients, 363 (72%) received active cancer treatment, 295 (58%) had at least one missed visit, 170 (34%) had multiple insurance, 87 (17%) lived in COZ, and 27 (5%) were pattern miss. For pattern miss, the rate was higher for patients in COZ vs those who were not (9/87 [10%] vs 18/418 [4%];p=0.036), and for patients with multiple insurance vs those with single insurance (16/170 [9%] vs 11/335 [3%];p=0.050). "No show" rate was higher among patients in active treatment vs those who were not (81/363 [22%] vs 20/142 [14%];p=0.03). Conclusion(s): Active cancer treatment was interestingly, and multiple insurance was ironically, associated with missed telemedicine visits. More remarkably, living in COZ was another barrier warranting attention. Measures are necessary to attenuate the disparity in accessing telemedicine.Copyright © 2023

Special Issue Editorial: Applications of 3D Printing for Polymers.

Polymer 3D printing is an emerging technology highly relevant in diverse industries, including medicine, electronics, and robotics [...].

Etiology of acute febrile illness in the peruvian amazon as determined by modular formatted quantitative PCR: a protocol for RIVERA, a health facility-based case-control study.

BACKGROUND: The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. METHODS: A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. DISCUSSION: The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 h and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific prevalent pathogens as a cause of acute illness. STUDY REGISTRATION: Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.

Changes in United States Residency Program Online Presence Following COVID-19.

PHENOMENON: The 2020-2021 residency application cycle was subject to major alterations following the COVID-19 global pandemic. This study determined the online presence of US-based residency training programs during this time period. APPROACH: An official list of accredited US residency programs for 24 medical specialties was obtained through the Electronic Residency Application Service Programs' online presence and was evaluated for website ownership in addition to Twitter, Instagram, and Facebook account ownership. Date of social media account foundation and virtual opportunities offered were recorded. Doximity Residency Navigator for 2020-2021 was used to determine program rank, and programs were stratified by location using Association of American Medical Colleges regions. Program rank and geographic location were used to determine potential trends in online presence. This study was performed during the residency application cycle from September 2, 2020, to November 29, 2020, during which applications were submitted and the interview cycle began. FINDINGS: Fifty-seven percent of the 4,562 programs had a presence on social media. One-third of all accounts were created after March 1, 2020, and most (58%) were residency program-associated. A total of 1,315 programs offered virtual open houses through Twitter (829), Instagram (792), and Facebook (295). First-quartile programs had significantly more social media accounts per program on average (1.8) than those in subsequent quartiles, and Western region programs had significantly more accounts per program on average (1.3) than the Central (1.0), Northeastern (1.0), and Southern (1.1) regions. INSIGHTS: US residency programs created social media accounts and online opportunities for applicants following March 1, 2020. Online interactions may serve as substitutes at a time when in-person interaction is not possible. Future studies may examine the influence and impact of virtual interactions.

Patient and Provider Perceptions of COVID-19-Driven Telehealth Use From Nurse-Led Care Models in Rural, Frontier, and Urban Colorado Communities.

The purpose of this study was to characterize the patient and provider engagement in the sudden telehealth implementation that occurred with the onset of the COVID-19 pandemic. Patients and providers from 3 nurse-led models of care (federally qualified health centers, nurse midwifery practices, and the Nurse-Family partnership program) in Colorado were surveyed. Data from the Patient Attitude toward Telehealth survey and Provider Perceptions about Telehealth were collected. Patient respondents (n = 308) who resided primarily in rural or frontier communities were female, white, and Hispanic. Patients in urban areas used telehealth more frequently than in rural or frontier areas (P < .001). Rural/Frontier patients had significantly lower attitude scores than urban patients across each of 5 domains assessed. Telehealth modality differed across location (P < .023), with video calls, used more frequently by urban providers, and phone calls used by rural/frontier providers. Our data highlight differences in telehealth access and attitudes across rurality. These findings may contribute to future policy while addressing barriers to telehealth access and delivery.

Etiology of Acute Febrile Illness in the Peruvian Amazon as determined by modular formatted quantitative PCR: A Protocol for RIVERA, a Health Facility-Based Case-Control Study (preprint)

Background: The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity.  We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. Methods: A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. Discussion: The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 hours and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific, prevalent pathogens as a cause of acute illness. Study Registration: Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.

Patient and Provider Perceptions of COVID-19-Driven Telehealth Use From Nurse-Led Care Models in Rural, Frontier, and Urban Colorado Communities

The purpose of this study was to characterize the patient and provider engagement in the sudden telehealth implementation that occurred with the onset of the COVID-19 pandemic. Patients and providers from 3 nurse-led models of care (federally qualified health centers, nurse midwifery practices, and the Nurse-Family partnership program) in Colorado were surveyed. Data from the Patient Attitude toward Telehealth survey and Provider Perceptions about Telehealth were collected. Patient respondents (n = 308) who resided primarily in rural or frontier communities were female, white, and Hispanic. Patients in urban areas used telehealth more frequently than in rural or frontier areas (P < .001). Rural/Frontier patients had significantly lower attitude scores than urban patients across each of 5 domains assessed. Telehealth modality differed across location (P < .023), with video calls, used more frequently by urban providers, and phone calls used by rural/frontier providers. Our data highlight differences in telehealth access and attitudes across rurality. These findings may contribute to future policy while addressing barriers to telehealth access and delivery.

Safety, tolerability, and efficacy of pirfenidone in patients with rheumatoid arthritis-associated interstitial lung disease: a randomised, double-blind, placebo-controlled, phase 2 study.

BACKGROUND: Interstitial lung disease is a known complication of rheumatoid arthritis, with a lifetime risk of developing the disease in any individual of 7·7%. We aimed to assess the safety, tolerability, and efficacy of pirfenidone for the treatment of patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). METHODS: TRAIL1 was a randomised, double-blind, placebo-controlled, phase 2 trial done in 34 academic centres specialising in interstitial lung disease in four countries (the UK, the USA, Australia, and Canada). Adults aged 18-85 years were eligible for inclusion if they met the 2010 American College of Rheumatology and European Alliance of Associations for Rheumatology criteria for rheumatoid arthritis and had interstitial lung disease on a high-resolution CT scan imaging and, when available, lung biopsy. Exclusion criteria include smoking, clinical history of other known causes of interstitial lung disease, and coexistant clinically significant COPD or asthma. Patients were randomly assigned (1:1) to receive 2403 mg oral pirfenidone (pirfenidone group) or placebo (placebo group) daily. The primary endpoint was the incidence of the composite endpoint of a decline from baseline in percent predicted forced vital capacity (FVC%) of 10% or more or death during the 52-week treatment period assessed in the intention-to-treat population. Key secondary endpoints included change in absolute and FVC% over 52 weeks, the proportion of patients with a decline in FVC% of 10% or more, and the frequency of progression as defined by Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT02808871. FINDINGS: From May 15, 2017, to March 31, 2020, 231 patients were assessed for inclusion, of whom 123 patients were randomly assigned (63 [51%] to the pirfenidone group and 60 [49%] to the placebo group). The trial was stopped early (March 31, 2020) due to slow recruitment and the COVID-19 pandemic. The difference in the proportion of patients who met the composite primary endpoint (decline in FVC% from baseline of 10% or more or death) between the two groups was not significant (seven [11%] of 63 patients in the pirfenidone group vs nine [15%] of 60 patients in the placebo group; OR 0·67 [95% CI 0·22 to 2·03]; p=0·48). Compared with the placebo group, patients in the pirfenidone group had a slower rate of decline in lung function, measured by estimated annual change in absolute FVC (-66 vs -146; p=0·0082) and FVC% (-1·02 vs -3·21; p=0·0028). The groups were similar with regards to the decline in FVC% by 10% or more (five [8%] participants in the pirfenidone group vs seven [12%] in the placebo group; OR 0·52 [95% CI 0·14-1·90]; p=0·32) and the frequency of progression as defined by OMERACT (16 [25%] in the pirfenidone group vs 19 [32%] in the placebo group; OR 0·68 [0·30-1·54]; p=0·35). There was no significant difference in the rate of treatment-emergent serious adverse events between the two groups, and there were no treatment-related deaths. INTERPRETATION: Due to early termination of the study and underpowering, the results should be interpreted with caution. Despite not meeting the composite primary endpoint, pirfenidone slowed the rate of decline of FVC over time in patients with RA-ILD. Safety in patients with RA-ILD was similar to that seen in other pirfenidone trials. FUNDING: Genentech.

Understanding the Spike Protein in COVID-19 Vaccine in Recombinant Vesicular Stomatitis Virus (rVSV) Using Automated Capillary Western Blots

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the viral agent that is responsible for the coronavirus disease-2019 (COVID-19) pandemic. One of the live virus vaccine candidates Merck and Co., Inc. was developing to help combat the pandemic was V590. V590 was a live-attenuated, replication-competent, recombinant vesicular stomatitis virus (rVSV) in which the envelope VSV glycoprotein (G protein) gene was replaced with the gene for the SARS-CoV-2 spike protein (S protein), the protein responsible for viral binding and fusion to the cell membrane. To assist with product and process development, a quantitative Simple Western (SW) assay was successfully developed and phase-appropriately qualified to quantitate the concentration of S protein expressed in V590 samples. A strong correlation was established between potency and S-protein concentration, which suggested that the S-protein SW assay could be used as a proxy for virus productivity optimization with faster data turnaround time (3 h vs 3 days). In addition, unlike potency, the SW assay was able to provide a qualitative profile assessment of the forms of S protein (S protein, S1 subunit, and S multimer) to ensure appropriate levels of S protein were maintained throughout process and product development. Finally, V590 stressed stability studies suggested that time and temperature contributed to the instability of S protein demonstrated by cleavage into its subunits, S1 and S2, and aggregation into S multimer. Both of which could potentially have a deleterious effect on the vaccine immunogenicity.

Formulation, inflammation, and RNA sensing impact the immunogenicity of self-amplifying RNA vaccines.

To be effective, RNA vaccines require both in situ translation and the induction of an immune response to recruit cells to the site of immunization. These factors can pull in opposite directions with the inflammation reducing expression of the vaccine antigen. We investigated how formulation affects the acute systemic cytokine response to a self-amplifying RNA (saRNA) vaccine. We compared a cationic polymer (pABOL), a lipid emulsion (nanostructured lipid carrier, NLC), and three lipid nanoparticles (LNP). After immunization, we measured serum cytokines and compared the response to induced antibodies against influenza virus. Formulations that induced a greater cytokine response induced a greater antibody response, with a significant correlation between IP-10, MCP-1, KC, and antigen-specific antibody titers. We then investigated how innate immune sensing and signaling impacted the adaptive immune response to vaccination with LNP-formulated saRNA. Mice that lacked MAVS and are unable to signal through RIG-I-like receptors had an altered cytokine response to saRNA vaccination and had significantly greater antibody responses than wild-type mice. This indicates that the inflammation induced by formulated saRNA vaccines is not solely deleterious in the induction of antibody responses and that targeting specific aspects of RNA vaccine sensing might improve the quality of the response.

Analytical sensitivity of COVID-19 rapid antigen tests: A case for a robust reference standard.

Aggressive diagnostic testing remains an indispensable strategy for health and aged care facilities to prevent the transmission of SARS-CoV-2 in vulnerable populations. The preferred diagnostic platform has shifted towards COVID-19 rapid antigen tests (RATs) to identify the most infectious individuals. As such, RATs are being manufactured faster than at any other time in our history yet lack the relevant quantitative analytics required to inform on absolute analytical sensitivity enabling manufacturers to maintain high batch-to-batch reproducibility, and end-users to accurately compare brands for decision making. Here, we describe a novel reference standard to measure and compare the analytical sensitivity of RATs using a recombinant GFP-tagged nucleocapsid protein (NP-GFP). Importantly, we show that the GFP tag does not interfere with NP detection and provides several advantages affording streamlined protein expression and purification in high yields as well as faster, cheaper and more sensitive quality control measures for post-production assessment of protein solubility and stability. Ten commercial COVID-19 RATs were evaluated and ranked using NP-GFP as a reference standard. Analytical sensitivity data of the selected devices as determined with NP-GFP did not correlate with those reported by the manufacturers using the median tissue culture infectious dose (TCID50) assay. Of note, TCID50 discordance has been previously reported. Taken together, our results highlight an urgent need for a reliable reference standard for evaluation and benchmarking of the analytical sensitivity of RAT devices. NP-GFP is a promising candidate as a reference standard that will ensure that RAT performance is accurately communicated to healthcare providers and the public.

Relapse activity and disability progression in COVIDvaccinated patients with multiple sclerosis: homologous vs. heterologous vaccination scheme

Background: Vaccination reduces the likelihood of a severe COVID-19 disease course. Therefore, vaccination against COVID-19 is generally recommended, even for people with autoimmune diseases such as multiple sclerosis (MS). Nevertheless, some people with MS (PwMS) have concerns about the vaccinations due to fear of disease worsening after the vaccinations. Objective(s): We aimed to analyse relapse activity and disability progression of PwMS stratified by COVID-19 vaccination scheme (homologous [HOM] vs. heterologous [HET]). Method(s): This study is based on a longitudinal observational study regarding the safety and tolerability of COVID-19 vaccines in PwMS. Acquisition of socio-demographic, clinical and vaccination data was conducted via several pseudonymised online surveys. PwMS with a minimum age of 18 years, a diagnosis of MS and a basic immunisation (usually two vaccinations) as well as >=1 booster vaccination against COVID-19 were included (N=2062). Patients with HOM (same vaccines) and HET vaccination schemes (different vaccines) were compared regarding relapse activity following vaccination and disability status (patient-determined disease steps [PDDS]). Result(s): The 2062 PwMS analysed showed a mean age of 47.1+/-11.0 years and a female proportion of 78.5%. The most common MS course was relapsing-remitting MS (74.8%). Most PwMS were currently treated with a disease-modifying drug (73.9%). Relapses after any COVID-19 vaccination occurred in 5.8% of PwMS. Comparing the disability level following the first vaccination with the period after the booster vaccination, a PDDS decrease was reported by 16.4% of PwMS, an increase by 13.6% and no change by 70.0%. The majority of patients reported a HOM vaccination scheme (59.4%), while 40.6% received HET vaccination (28.0%: different mRNA vaccines [HET1], 12.6%: mRNA + vector vaccines [HET2]). The only significant difference (p=0.012) between patients stratified by vaccination scheme was related to the mean age: PwMS receiving HOM vaccination (46.5+/-11.2 years) were younger than patients with HET vaccination (HET1: 48.4 years, HET2: 48.1 years). These patient subgroups revealed no considerable difference regarding the frequency of relapses following vaccination (HOM: 4.7%, HET1: 5.2%, HET2: 6.9%;p=0.3). Conclusion(s): The frequency of relapses and disability progression following COVID vaccinations do not appear to be associated with the type of vaccination regimen administered.

An evaluation of the risk of airborne transmission of COVID-19 on an inter-city train carriage.

Experiments were conducted in an UK inter-city train carriage with the aim of evaluating the risk of infection to the SARS-CoV-2 virus via airborne transmission. The experiments included in-service CO2 measurements and the measurement of salt aerosol concentrations released within the carriage. Computational fluid dynamics simulations of the carriage airflow were also used to visualise the airflow patterns, and the efficacy of the HVAC filter material was tested in a laboratory. Assuming an infectious person is present, the risk of infection for a 1-h train journey was estimated to be 6 times lower than for a full day in a well-ventilated office, or 10-12 times lower than a full day in a poorly ventilated office. While the absolute risk for a typical journey is likely low, in the case where a particularly infectious individual is on-board, there is the potential for a number of secondary infections to occur during a 1-h journey. Every effort should therefore be made to minimize the risk of airborne infection within these carriages. Recommendations are also given for the use of CO2 sensors for the evaluation of the risk of airborne transmission on train carriages.