Sensitivity Analysis of Medical Waste Sterilization Shredder Using Surrogate Model

Medical waste has been excessively generated in various medical facilities due to COVID-19, and its treatment has become an important concern. Previously, an optimized medical waste sterilization and shredding system was developed for hospital scale but due to increased demand, it is necessary to scale such a system for different facilities. Therefore, in this paper, a sensitivity analysis for the design variables of the shredding system has been conducted and a surrogate model is developed for stress estimation. The surrogate model was generated using LHS (Latin hypercube sampling), which can represent the overall information of the design domain with a limited number of samples. The surrogate model was then used to increase the number of samples for sensitivity analysis which helped in reducing the computational time for finite element analysis. The sensitive variables for the shredder system were then estimated using sensitivity analysis. Consequently, an efficient design framework for various capacities of medical waste shredder was suggested using sensitivity analysis and a data-driven surrogate model.

Effect of vaccine dosing intervals on Omicron surrogate neutralization after three doses of BNT162b2.

Background: Increasing the interval between the first and second SARS-CoV-2 vaccine doses enhances vaccine immunogenicity, however the optimal timing of the third vaccine is unknown. In this study, we investigated how the time interval between the first and second (V1-V2), or second and third (V2-V3) doses affects immunogenicity after three doses of the BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine. Methods: This is an observational cohort consisting of 360 participants enrolled in the COVID-19 Occupational Risks, Seroprevalence, and Immunity among Paramedics in Canada (CORSIP) study. Immune responses to BA.1 and other variants were measured from serum using an ACE2 competitive binding assay for surrogate SARS-CoV-2 neutralization. We fit a multiple linear regression model to estimate the independent association between both the V1-V2 and V2-V3 intervals and serum SARS-CoV-2 neutralization, while adjusting for age, sex, and the V3-to-blood collection interval. We examined vaccine dosing intervals as continuous variables and categorized them into quartiles. Results: The mean age was 40 years, 45% were female sex (at birth), and the median BA.1 surrogate neutralization was 61% (IQR 38-77%). The multivariate analysis indicated that longer V1-V2 (ß = 0.1292, 95% CI: 0.04807-0.2104) and V2-V3 (ß = 0.2653, 95% CI: 0.2291-0.3015) intervals were associated with increased surrogate neutralization of BA.1. These results were consistent when examining responses against Spike from other SARS-CoV-2 strains. When categorized into V2-V3 quartiles, the first (56-231 days), and second (231-266 days) quartiles demonstrated decreased BA.1 surrogate neutralization compared to the longest V2-V3 quartile (282-329 days). There was no significant difference in surrogate neutralization between the long (266-282 days) and longest (282-329 days) V2-V3 intervals. Conclusion: Longer intervals between first, second and third doses are independently associated with increased immunogenicity for all tested SARS-CoV-2 strains. Increasing the intervals between the second and third vaccine doses up to 8.9 months provided additive benefits increasing the immunogenicity of BNT162b2 vaccine schedules.

UV radiation sensitivity of bacteriophage PhiX174- A potential surrogate for SARS-CoV-2 in terms of radiation inactivation

To minimize health risks, surrogates are often employed to reduce experiments with pathogenic microorganisms and the associated health risk. Due to structural similarities between the enveloped RNA -viruses SARS-CoV-2 and Phi6, the latter has been established as a nonpathogenic coronavirus surrogate for many applications. However, large discrepancies in the UV log-reduction doses between SARS-CoV-2 and Phi6 necessitate the search for a better surrogate for UV inactivation applications. A literature study provided the bacteriophage PhiX174 as a potentially more suitable nonpathogenic coronavirus surrogate candidate. In irradiation experiments, the sensitivity of PhiX174 was investigated upon exposure to UV radiation of wavelengths 222 nm (Far-UVC), 254 nm (UVC), 302 nm (broad-band UVB), 311 nm (narrow-band UVB) and 366 nm (UVA) using a plaque assay. The determined log-reduction doses for PhiX174 were 1.3 mJ/cm2 @ 222 nm, 5 mJ/cm2 @ 254 nm, 17.9 mJ/cm2 @ 302 nm, 625 mJ/cm2 @ 311 nm and 42.5 J/cm2 @ 366 nm. The comparison of these results with published log-reduction doses of SARS-CoV-2 in the same spectral region, led to the conclusion that the bacteriophage PhiX174 exhibits larger log-reduction doses than SARS-CoV-2, nevertheless, it is a better UV-surrogate at 222 nm (Far-UVC), 254 nm (UVC) and 302 nm (UVB) than the often applied Phi6.

Attentive Multi-Task Prediction of Atmospheric Particulate Matter: Effect of the COVID-19 Pandemic

Air pollution, especially the continual increase in atmospheric particulate matter (PM), is a global environmental challenge. To reduce the PM concentration, a remarkable amount of machine learning-based research has been proposed. However, increasing the accuracy of the predictions and providing clear interpretations of the predictions are challenging. In particular, no studies have addressed models that predict and interpret PM before and during the COVID-19 pandemic. In this paper, we present a two-step predictive and explainable model to obtain insights into reducing PM. We first use attentive multi-task learning to predict the air quality of cities. To accurately predict the concentration of particles with sizes of similar to 10 mu m or similar to 2.5 mu m (PM10 and PM2.5, respectively), we demonstrate a performance difference between single-task and multi-task learning, as well as among the state-of-the art methods. The proposed attentive model with multi-task learning outperformed the others in terms of accuracy performance. We then used Shapley additive explanations, a representative explainable artificial intelligence framework, to interpret and determine the significance of features for predicting PM10 and PM2.5. We demonstrated the superiority of the proposed approach in predicting and explaining both PM10 and PM2.5 concentrations, and observed a statistically significant difference in air pollution before and during the COVID-19 pandemic.

Persistence and Dynamicity of Sars-Cov-2 Antibody Response after Double Dose of Bbv-152 and Azd1222 Vaccines: A Prospective, Longitudinal, Year-Long Cohort Study

Intro: Different vaccines against COVID-19 have been approved by the World Health Organization (WHO) at different stages, however, limited data is available on long-term kinetics of antibodies induced by vaccines. This study was performed to investigate the persistence and dynamicity of BBV-152 (Covaxin)- and AZD1222 (Covishield)-induced immunoglobulin-G (IgG) antibodies over the year and neutralizing antibodies' status after the one-month post booster dose. Method(s): This 52-week longitudinal cohort study documented antibody persistence and neutralizing antibody status among 278 health-care workers (HCWs) from four different healthcare and research facilities in Odisha, enrolled in January 2021 and continued until March 2022. An automated chemiluminescence immune assay (CLIA) platform from Abbott Diagnostics was used to quantify IgG antibodies against SARS-CoV-2's spike receptor-binding domain (RBD) and a surrogate virus neutralization test (sVNT) was performed by enzyme-linked immunosorbent assay (ELISA). If any participants developed any symptoms of COVID-19, nasopharyngeal swabs were collected and sent to ICMR- RMRC, Bhubaneswar for RT-PCR confirmation. Finding(s): Among the 243 participants, 119 HCWs (48.97%) were Covaxin recipients and the remaining 124 (51.02%) were Covishield recipients. During the seven follow- ups, 104 participants (42.79%) were identified as vaccine breakthrough cases. In 139 non-infected HCWs, the median antibody titer significantly waned after ten months of double dose, both for Covaxin (342.7 AU/mL at DD1 vs 43.9 AU/mL at DD10) and Covishield (2325.8 AU/mL at DD3 vs 595.2 AU/mL at DD10). No statistically significant differences in antibody titers were observed based on age, gender, comorbidities, and blood groups. The median inhibition activity of sVNT was increased significantly for Covaxin and Covishield booster recipients. Among the booster dose recipients, 24 had breakthrough cases by the Omicron variant. Conclusion(s): Results of this longitudinal cohort study can be used to implement vaccination strategies and could also aid in tracking and designing vaccine mandates to minimize vaccine escape.Copyright © 2023

Detection of SARS-CoV-2 Antibodies: Comparison of Enzyme Immunoassay, Surrogate Neutralization and Virus Neutralization Test.

BACKGROUND: Since sensitivity and specificity vary widely between tests, SARS-CoV-2 serology results should be interpreted with caution. METHODS: The study included serum samples from patients who had recovered from COVID-19 (n = 71), individuals vaccinated against SARS-CoV-2 (n = 84), and asymptomatic individuals (n = 33). All samples were tested for the presence of binding antibodies (enzyme immunoassay; EIA), neutralizing (NT) antibodies (virus neutralization test; VNT), and surrogate NT (sNT) antibodies (surrogate virus neutralization test; sVNT) of SARS-CoV-2. RESULTS: SARS-CoV-2-binding antibodies were detected in 71 (100%) COVID-19 patients, 77 (91.6%) vaccinated individuals, and 4 (12.1%) control subjects. Among EIA-positive samples, VNT was positive (titer ≥ 8) in 100% of COVID-19 patients and 63 (75.0%) of the vaccinated individuals, while sVNT was positive (>30% inhibition) in 62 (87.3%) patients and 59 (70.2%) vaccinated individuals. The analysis of antibody levels showed a significant moderate positive correlation between EIA and VNT, a moderate positive correlation between EIA and sVNT, and a strong positive correlation between VNT and sVNT. The proportion of positive sVNT detection rate was associated with VNT titer. The lowest positivity (72.4%/70.8%) was detected in samples with low NT titers (8/16) and increased progressively from 88.2% in samples with titer 32 to 100% in samples with titer 256. CONCLUSIONS: sVNT appeared to be a reliable method for the assessment COVID-19 serology in patients with high antibody levels, while false-negative results were frequently observed in patients with low NT titers.

Antiviral activity of nano-monocaprin against Phi6 as a surrogate for SARS-CoV-2.

The COVID-19 pandemic involving SARS-CoV-2 has raised interest in using antimicrobial lipid formulations to inhibit viral entry into their host cells or to inactivate them. Lipids are a part of the innate defense mechanism against pathogens. Here, we evaluated the use of nano-monocaprin (NMC) in inhibiting enveloped (phi6) and unenveloped (MS2) bacteriophages. NMC was prepared using the sonochemistry technique. Size and morphology analysis revealed the formation of ~ 8.4 ± 0.2-nm NMC as measured by dynamic light scattering. We compared the antiviral activity of NMC with molecular monocaprin (MMC) at 0.5 mM and 2 mM concentrations against phi6, which we used as a surrogate for SARS-CoV-2. The synthesized NMC exhibited 50% higher antiviral activity against phi6 than MMC at pH 7 using plaque assay. NMC inactivated phi6 stronger at pH 4 than at pH 7. To determine if NMC is toxic to mammalian cells, we used MTS assay to assess its IC50 for HPDE and HeLa cell lines, which were ~ 203 and 221 µM, respectively. NMC may be used for prophylactic application either as a drop or spray since many viruses enter the human body through the mucosal lining of the nose, eyes, and lungs.

Development of SARS-CoV-2 neutralizing antibody detection assay by using recombinant plant-produced proteins.

Detecting immunity against SARS-CoV-2 is vital for evaluating vaccine response and natural infection, but conventional virus neutralization test (cVNT) requires BSL3 and live viruses, and pseudo-virus neutralization test (pVNT) needs specialized equipment and trained professionals. The surrogate virus neutralization test (sVNT) was developed to overcome these limitations. This study explored the use of angiotensin converting enzyme 2 (ACE2) produced from Nicotiana benthamiana for the development of an affordable neutralizing antibodies detection assay. The results showed that the plant-produced ACE2 can bind to the receptor binding domain (RBD) of the SARS-CoV-2, and was used to develop sVNT with plant-produced RBD protein. The sVNT developed using plant-produced proteins showed high sensitivity and specificity when validated with a group of 30 RBD vaccinated mice sera and the results were correlated with cVNT titer. This preliminary finding suggests that the plants could offer a cost-effective platform for producing diagnostic reagents.

Kinetics and ability of binding antibody and surrogate virus neutralization tests to predict neutralizing antibodies against the SARS-CoV-2 Omicron variant following BNT162b2 booster administration.

OBJECTIVES: To assess the long-term humoral immunity induced by booster administration, as well as the ability of binding antibody and surrogate virus neutralization tests (sVNT) to predict neutralizing antibodies (NAbs) against the SARS-CoV-2 Omicron variant. METHODS: A total of 269 sera samples were analyzed from 64 healthcare workers who had received a homologous booster dose of BNT162b2. Neutralizing antibodies assessed by sVNT and anti-RBD IgG measured with the sCOVG assay (Siemens Healthineers®) were analyzed at five timepoints; before and up to 6 months following the booster. Antibody titers were correlated with neutralizing antibodies against the Omicron BA.1 variant obtained by pseudovirus neutralization test (pVNT) as a reference method. RESULTS: While Wild-type sVNT percentage of inhibition (POI) remained above 98.6% throughout the follow-up period after booster administration, anti-RBD IgG and NAbs assessed by Omicron BA.1 pVNT showed respectively a 3.4-fold and 13.3-fold decrease after 6 months compared to the peak reached at day 14. NAbs assessed by Omicron sVNT followed a steady decline until reaching a POI of 53.4%. Anti-RBD IgG and Omicron sVNT assays were strongly correlated (r=0.90) and performed similarly to predict the presence of neutralizing antibodies with Omicron pVNT (area under the ROC: 0.82 for both assays). In addition, new adapted cut-off values of anti-RBD IgG (>1,276 BAU/mL) and Omicron sVNT (POI>46.6%) were found to be better predictors of neutralizing activity. CONCLUSIONS: This study showed a significant drop in humoral immunity 6 months after booster administration. Anti-RBD IgG and Omicron sVNT assays were highly correlated and could predict neutralizing activity with moderate performance.

A Longitudinal Study in Turkiye of Host Ability to Produce Antibodies following a Third Homologous BNT162b2 Vaccination.

Obesity is a multifaceted, complex condition that has negative impacts on one's health. There are conflicting reports regarding the COVID-19 vaccine's ability to induce antibody formation in obese people. Our study aimed to determine anti-S-RBD IgG and surrogate neutralizing antibody (snAb) levels before and after the third Pfizer-BioNTech (BNT162b2) vaccination (at 15, 60, 90, and 120 days) in normal-weight adults, overweight, and obese individuals without any comorbidity or previous SARS-CoV-2 infection history, but it did not evaluate the response to the first two doses. In this longitudinal prospective study in Istanbul, Turkey, a total of 323 consecutive adult individuals (141 normal weight, 108 overweight, and 74 patients with obesity) were included. Peripheral blood samples were collected. Anti-S-RBD IgG and surrogate neutralizing antibody levels were detected using the ELISA method. After the third dose of BNT162b2 vaccination, obese patients had significantly lower levels of snAb against SARS-CoV-2 compared with normal-weight controls, but the levels otherwise did not differ between the study groups. Across all individuals in our cohort, titers peaked about a month after this third vaccination and then gradually faded. Anti-S-RBD IgG and snAb IH% levels against SARS-CoV-2 were not correlated with IL-6 and TNF-α levels. In conclusion, anti-S-RBD IgG titers and snAb IH% levels against SARS-CoV-2 were determined longitudinally for 120 days after the third homologous BNT162b2 vaccination. Although there were no significant differences in anti-S-RBD IgG, we found significant differences in the snAb IH% levels against SARS-CoV-2 between obese and healthy control subjects.

Transfer of Phi6 bacteriophage between human skin and surfaces common to consumer-facing environments.

AIMS: This study aimed to determine the extent of Phi6 (Φ6) transfer between skin and surfaces relevant to consumer-facing environments based on inoculum matrix, surface type and contact time. METHODS AND RESULTS: Φ6 transfer rates were determined from skin-to-fomite and fomite-to-skin influenced by inoculum matrix (artificial saliva and tripartite), surface type (aluminium, plastic, stainless steel, touchscreen, vinyl and wood) and contact time (5 and 10 s). Significant differences in estimated means were observed based on surface type (both transfer directions), inoculum matrix (skin-to-fomite) and contact time (both transfer directions). During a sequential transfer experiment from fomite-to-skin, the maximum number of consecutive transfer events observed was 3.33 ± 1.19, 2.33 ± 1.20 and 1.67 ± 1.21 for plastic, touchscreen and vinyl, respectively. CONCLUSIONS: Contact time significantly impacted Φ6 transfer rates, which may be attributed to skin absorption dynamics. Surface type should be considered for assessing Φ6 transfer rates. SIGNIFICANCE AND IMPACT OF THE STUDY: Although the persistence of Φ6 on fomites has been characterized, limited data are available regarding the transfer of Φ6 among skin and fomites. Determining Φ6 transfer rates for surfaces in consumer-facing environments based on these factors is needed to better inform future virus transmission mitigation strategies.

Immunogenicity and Safety of Homologous Chadox1 Ncov-19 and Heterologous Prime-Boost of Coronavac and Chadox1 Ncov-19 among Kidney Transplant Recipients: An Observational Prospective Cohort Study

Introduction: Kidney transplant recipients (KTRs) are at risk for substantial morbidity and mortality during COVID-19 infection. Vaccination for this group of patients is reccommended. However, immunogenicity and safety data after COVID-19 vaccination among KTRs remains limited. Method(s): We conducted an observational prospective trial involving KTRs at Chiang Mai University hospital, Chiang Mai, Thailand. The participants were received homologous ChAdOx1 nCoV-19 (AZ-AZ), or the heterologous prime-boost of CoronaVac,followed by AZ (SV-AZ). The immunogenicity was assessed by measuring antibodies against the S1 receptor-binding domain (anti-RBD), and SARS-CoV-2 surrogate virus neutralization test (sVNT) at specific timepoints. The primary outcome was the seroconversion rate of sVNT at day 28 after complete vaccination. The secondary outcomes were the seroconversion rate of sVNT at day 28 after the first dose of vaccination, the level of sVNT and anti-RBD at specific timepoints, and the adverse events of each vaccine regimen. Result(s): A total of 18 KTRs were recruited. Among those, 13 (72.2%), and 5 (27.8%) patients were received AZ-AZ, and SV-AZ regimen, respectively. The seroconversion rate of sVNT at day 28 after the second dose were 23.1%, and 20.0% for AZ-AZ, and SV-AZ, respectively (P>0.99). The level of sVNT and the level of anti-RBD at day 28 after the first and at day 28 after the second dose were not different between groups (Figure 1). There were no serious adverse events reported in any vaccine groups. However, AZ-AZ showed sign of tubular dysfunction demonstrated by increasing of fractional excretion of magnesium after complete course of vaccination which correlated to the trend of urine albumin and urine protein creatinine ratio (r=0.720, P=0.013;and r=0.726, P=0.011, respectively). [Formula presented] [Formula presented] Figure 1 Percentage of neutralization inhibition (a) and level of anti-RBD antibody (b) at each visit of homologous ChAdOx1 nCoV-19 (AZ-AZ), and heterologous prime-boost of CoronaVac, followed by AZ (SV-AZ) regimen Conclusion(s): Immunogenicity after COVID-19 vaccination with either homologous or heterologous prime-boost regimen among KTRs was compromised. Homologous replication-defective viral vectors vaccine regimen seemed to affect renal tubular function, and further follow-up should be warranted. No conflict of interestCopyright © 2023

Observed sidewalk autonomous delivery robot interactions with pedestrians and bicyclists

The recent deployment of sidewalk autonomous delivery robots (SADRs) across university campuses has offered students, staff, and faculty a convenient option for food delivery to their residences or workplaces. However, these low-speed automated food delivery services, which were first commercially deployed on American campuses in early 2019 and continued to offer an important contactless delivery service during the height of the Covid-19 pandemic, traverse campuses on pathways originally designed for pedestrians and bicyclists, creating a potential for conflicts among the different pathway users and potentially unsafe transportation conditions. This study examines one week of field-recorded video from ten locations across the Northern Arizona University campus to help understand the prevalence and severity of SADR-involved interactions with pedestrians and bicyclists. The severity of SADR-involved interactions was quantified by using the surrogate safety measure of post-encroachment time, which was then modeled as a function of conflict- and site-level characteristics to identify predictors of moderate or dangerous conflicts between SADRs and human pathway users. Findings from this study, which provides initial real-world insights into the impacts of SADRs sharing pathways with pedestrians and bicyclists, are intended to help inform facility management strategies capable of supporting the safe introduction of this emerging autonomous freight technology on shared-use facilities in current and potential future settings. © 2023 The Author(s)

Detection and Diagnosis Technologies for SARS-CoV-2

Detection and diagnosis platforms play key roles in early warning, outbreak control and exit strategy for any pandemic, and they are especially pertinent for the Coronavirus disease 2019 (COVID-19) pandemic. The challenges posed by the speed and extent of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) spread around the globe also offered unprecedented opportunities for the development and deployment of novel strategies and products - not only vaccines and therapeutics, but also diagnostics. This chapter provides a brief summary of the vast array of molecular, serological, cell-based and other diagnostic tools for the specific detection of SARS-CoV-2 infections and immune responses. The focus is on the principles and applications of each platform, while detailed protocols can be found in the cited references. © 2023 by World Scientific Publishing Co. Pte. Ltd.

Parents' digital Labor and disrupted parent-teacher relationships: theorizing Chinese parents' voices from the home-based online learning

The digital age has fundamentally altered the distribution of work and responsibilities in schools. Parents, as important stakeholders in schooling, are taking on more digital labour and facing changing roles. Before the COVID-19 pandemic, parents' digital labour often remained overlooked as they were not able to observe or participate in the whole process of schooling in the school. However, home-based online learning during the pandemic lockdown has created a rare situation of integrating technology into schooling, expanding parental involvement, and providing an opportunity to systematically explore the digital labour of parents and the influence of parent-teacher power relations in this regard. Using qualitative data from an open-ended parent survey in China, this study finds that parents take on the dual roles of regular parent and "surrogate teacher” in home-based online learning during the pandemic. Behind these two roles is a spectrum of digital labour ranging from technical support, notification delivery, and homework submission to monitoring and guiding school learning, learning content and time management, and learning-related communications with teachers. While technology strengthens existing unequal power relations, it also breaks teachers' monopoly over teaching affairs. Parents thus experience mixed emotions and develop a sense of shared responsibility and empathy with teachers. © 2023 National Institute of Education, Singapore.

Psychological components of infertility

Infertility is a medical diagnosis impacting 48.5 million couples globally. Infertility impacts physical and emotional health as well as social and romantic relationships. People with infertility report feelings of distress, grief, anxiety and depression. Couples notice changes in their relationships;some report becoming emotionally closer while others report relationship difficulties. People may feel more isolated due to lack of social support. People that use third party reproduction, such as donor egg, sperm, embryo or gestational carriers, have additional emotional impacts during pregnancy and parenting. Continuing changes to laws complicate international fertility care, particularly given the ongoing COVID-19 pandemic. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

A Demand-Side Inoperability Input–Output Model for Strategic Risk Management: Insight from the COVID-19 Outbreak in Shanghai, China

This paper proposes the dynamic inoperability input–output model (DIIM) to analyze the economic impact of COVID-19 in Shanghai in the first quarter of 2022. Based on the input–output model, the DIIM model introduces the sector elasticity coefficient, assesses the economic loss of the system and the influence of disturbances on other sectors through sectoral dependence, and simulates the inoperability and economic loss changes through time series. A multi-evaluation examination of the results reveals that the degree of inoperability of sub-sectors is inconsistent with the ranking of economic losses and that it is hard to quantify the impact of each sector directly. Different from the traditional DIIM model that only considers the negative part of the disaster, the innovation of this paper is that the negative value of the inoperability degree is used to measure the indirect positive growth of sectors under the impact of the Shanghai pandemic shock. At the same time, policymakers need to consider multi-objective optimization when making risk management decisions. This study uses surrogate worth trade-off to construct a multi-objective risk management framework to expand the DIIM model to enable policymakers to quantify the trade-off between economic benefit and investment costs when making risk management decisions. © 2023 by the authors.

Viral Preservation with Protein-Supplemented Nebulizing Media in Aerosols.

The outbreak of SARS-CoV-2 has emphasized the need for a deeper understanding of infectivity, spread, and treatment of airborne viruses. Bacteriophages (phages) serve as ideal surrogates for respiratory pathogenic viruses thanks to their high tractability and the structural similarities tailless phages bear to viral pathogens. However, the aerosolization of enveloped SARS-CoV-2 surrogate phi6 usually results in a >3-log10 reduction in viability, limiting its usefulness as a surrogate for aerosolized coronavirus in "real world" contexts, such as a sneeze or cough. Recent work has shown that saliva or artificial saliva greatly improves the stability of viruses in aerosols and microdroplets relative to standard dilution/storage buffers like suspension medium (SM) buffer. These findings led us to investigate whether we could formulate media that preserves the viability of phi6 and other phages in artificially derived aerosols. Results indicate that SM buffer supplemented with bovine serum albumin (BSA) significantly improves the recovery of airborne phi6, MS2, and 80α and outperforms commercially formulated artificial saliva. Particle sizing and acoustic particle trapping data indicate that BSA supplementation dose-dependently improves viral survivability by reducing the extent of particle evaporation. These data suggest that our viral preservation medium may facilitate a lower-cost alternative to artificial saliva for future applied aerobiology studies. IMPORTANCE We have identified common and inexpensive lab reagents that confer increased aerosol survivability on phi6 and other phages. Our results suggest that soluble protein is a key protective component in nebulizing medium. Protein supplementation likely reduces exposure of the phage to the air-water interface by reducing the extent of particle evaporation. These findings will be useful for applications in which researchers wish to improve the survivability of these (and likely other) aerosolized viruses to better approximate highly transmissible airborne viruses like SARS-CoV-2.

Could Prior COVID-19 Affect the Neutralizing Antibody after the Third BNT162b2 Booster Dose: A Longitudinal Study.

Vaccination is an essential public health measure for preventing the spread of illness during this continuing COVID-19 epidemic. The immune response developed by the host or the continuation of the immunological response caused by vaccination is crucial since it might alter the epidemic's prognosis. In our study, we aimed to determine the titers of anti-S-RBD antibody and surrogate neutralizing antibody (snAb) formed before and after the third dose of the BNT162b2 vaccination (on the 15th, 60th, and 90th days) in healthy adults who did not have any comorbidity either with or without prior SARS-CoV-2 infection. In this longitudinal prospective study, 300 healthy persons were randomly included between January and February 2022, following two doses of BNT162b2 immunization and before a third dosage. Blood was drawn from the peripheral veins. SARS-CoV-2 NCP IgG and anti-S-RBD IgG levels were detected by the CMIA method, and a surrogate neutralizing antibody was seen by the ELISA method. Our study included 154 (51.3%) female and 146 (48.7%) male (total 300) participants. The participants' median age was 32.5 (IQR:24-38). It was discovered that 208 individuals (69.3%) had never been infected with SARS-CoV-2, whereas 92 participants (30.7%) had SARS-CoV-2 infections in the past. Anti-S-RBD IgG and nAb IH% levels increased 5.94- and 1.26-fold on day 15, 3.63- and 1.22-fold on day 60, and 2.33- and 1.26-fold on day 90 after the third BNT162b2 vaccine dosage compared to pre-vaccination values (Day 0). In addition, the decrease in anti-S-RBD IgG levels on the 60th and 90th days was significantly different in the group without prior SARS-CoV-2 infection compared to the group with past SARS-CoV-2 infection (p < 0.05). In conclusion, it was observed that prior SARS-CoV-2 infection and the third BNT162b2 vaccine dose led to a lower decrease in both nAb and anti-S-RBD IgG levels. To evaluate the vaccine's effectiveness and update immunization programs, however, it is necessary to perform multicenter, longer-term, and comprehensive investigations on healthy individuals without immune response issues, as there are still circulating variants.

Persistence of spike-specific immune responses in BNT162b2-vaccinated donors and generation of rapid ex-vivo T cells expansion protocol for adoptive immunotherapy: A pilot study.

Introduction: The BNT162b2 mRNA-based vaccine has shown high efficacy in preventing COVID-19 infection but there are limited data on the types and persistence of the humoral and T cell responses to such a vaccine. Methods: Here, we dissect the vaccine-induced humoral and cellular responses in a cohort of six healthy recipients of two doses of this vaccine. Results and discussion: Overall, there was heterogeneity in the spike-specific humoral and cellular responses among vaccinated individuals. Interestingly, we demonstrated that anti-spike antibody levels detected by a novel simple automated assay (Jess) were strongly correlated (r=0.863, P<0.0001) with neutralizing activity; thus, providing a potential surrogate for neutralizing cell-based assays. The spike-specific T cell response was measured with a newly modified T-spot assay in which the high-homology peptide-sequences cross-reactive with other coronaviruses were removed. This response was induced in 4/6 participants after the first dose, and all six participants after the second dose, and remained detectable in 4/6 participants five months post-vaccination. We have also shown for the first time, that BNT162b2 vaccine enhanced T cell responses also against known human common viruses. In addition, we demonstrated the efficacy of a rapid ex-vivo T cell expansion protocol for spike-specific T cell expansion to be potentially used for adoptive-cell therapy in severe COVID-19, immunocompromised individuals, and other high-risk groups. There was a 9 to 13.7-fold increase in the number of expanded T cells with a significant increase of anti-spike specific response showing higher frequencies of both activation and cytotoxic markers. Interestingly, effector memory T cells were dominant in all four participants' CD8+ expanded memory T cells; CD4+ T cells were dominated by effector memory in 2/4 participants and by central memory in the remaining two participants. Moreover, we found that high frequencies of CD4+ terminally differentiated memory T cells were associated with a greater reduction of spike-specific activated CD4+ T cells. Finally, we showed that participants who had a CD4+ central memory T cell dominance expressed a high CD69 activation marker in the CD4+ activated T cells.