Convalescent human IgG, but not IgM, from COVID-19 survivors confers dose-dependent protection against SARS-CoV-2 replication and disease in hamsters

Introduction

Antibody therapeutic strategies have served an important role during the COVID-19 pandemic, even as their effectiveness has waned with the emergence of escape variants. Here we sought to determine the concentration of convalescent immunoglobulin required to protect against disease from SARS-CoV-2 in a Syrian golden hamster model.

Methods

Total IgG and IgM were isolated from plasma of SARS-CoV-2 convalescent donors. Dose titrations of IgG and IgM were infused into hamsters 1 day prior to challenge with SARS-CoV-2 Wuhan-1.

Results

The IgM preparation was found to have ~25-fold greater neutralization potency than IgG. IgG infusion protected hamsters from disease in a dose-dependent manner, with detectable serum neutralizing titers correlating with protection. Despite a higher in vitro neutralizing potency, IgM failed to protect against disease when transferred into hamsters.

Discussion

This study adds to the growing body of literature that demonstrates neutralizing IgG antibodies are important for protection from SARS-CoV-2 disease, and confirms that polyclonal IgG in sera can be an effective preventative strategy if the neutralizing titers are sufficiently high. In the context of new variants, against which existing vaccines or monoclonal antibodies have reduced efficacy, sera from individuals who have recovered from infection with the emerging variant may potentially remain an efficacious tool.

A multispecific antibody prevents immune escape and confers pan-SARS-CoV-2 neutralization

Despite effective countermeasures, SARS-CoV-2 persists worldwide due to its ability to diversify and evade human immunity1. This evasion stems from amino-acid substitutions, particularly in the receptor-binding domain of the spike, that confer resistance to vaccines and antibodies 2-16. To constrain viral escape through resistance mutations, we combined antibody variable regions that recognize different receptor binding domain (RBD) sites17,18 into multispecific antibodies. Here, we describe multispecific antibodies, including a trispecific that prevented virus escape >3000-fold more potently than the most effective clinical antibody or mixtures of the parental antibodies. Despite being generated before the evolution of Omicron, this trispecific antibody potently neutralized all previous variants of concern and major Omicron variants, including the most recent BA.4/BA.5 strains at nanomolar concentrations. Negative stain electron microscopy revealed that synergistic neutralization was achieved by engaging different epitopes in specific orientations that facilitated inter-spike binding. An optimized trispecific antibody also protected Syrian hamsters against Omicron variants BA.1, BA.2 and BA.5, each of which uses different amino acid substitutions to mediate escape from therapeutic antibodies. Such multispecific antibodies decrease the likelihood of SARS-CoV-2 escape, simplify treatment, and maximize coverage, providing a strategy for universal antibody therapies that could help eliminate pandemic spread for this and other pathogens.

Protocol paper: Multi-site, cluster-randomized clinical trial for optimizing functional outcomes of older cancer survivors after chemotherapy

BACKGROUND

Cancer survivors over the age of 65 have unique needs due to the higher prevalence of functional and cognitive impairment, comorbidities, geriatric syndromes, and greater need for social support after chemotherapy. In this study, we will evaluate whether a Geriatric Evaluation and Management-Survivorship (GEMS) intervention improves functional outcomes important to older cancer survivors following chemotherapy.

METHODS

A cluster-randomized trial will be conducted in approximately 30 community oncology practices affiliated with the University of Rochester Cancer Center (URCC) National Cancer Institute Community Oncology Research Program (NCORP) Research Base. Participating sites will be randomized to the GEMS intervention, which includes Advanced Practice Practitioner (APP)-directed geriatric evaluation and management (GEM), and Survivorship Health Education (SHE) that is combined with Exercise for Cancer Patients (EXCAP©®), or usual care. Cancer survivors will be recruited from community oncology practices (of participating oncology physicians and APPs) after the enrolled clinicians have consented and completed a baseline survey. We will enroll 780 cancer survivors aged 65 years and older who have completed curative-intent chemotherapy for a solid tumor malignancy within four weeks of study enrollment. Cancer survivors will be asked to choose one caregiver to also participate for a total up to 780 caregivers. The primary aim is to compare the effectiveness of GEMS for improving patient-reported physical function at six months. The secondary aim is to compare effectiveness of GEMS for improving patient-reported cognitive function at six months. Tertiary aims include comparing the effectiveness of GEMS for improving: 1) Patient-reported physical function at twelve months; 2) objectively assessed physical function at six and twelve months; and 3) patient-reported cognitive function at twelve months and objectively assessed cognitive function at six and twelve months. Exploratory health care aims include: 1) Survivor satisfaction with care, 2) APP communication with primary care physicians (PCPs), 3) completion of referral appointments, and 4) hospitalizations at six and twelve months. Exploratory caregiver aims include: 1) Caregiver distress; 2) caregiver quality of life; 3) caregiver burden; and 4) satisfaction with patient care at six and twelve months.

DISCUSSION

If successful, GEMS would be an option for a standardized APP-led survivorship care intervention.

TRIAL REGISTRATION

ClinicalTrials.govNCT05006482, registered on August 9, 2021.

Passive transfer of Ad26.COV2.S-elicited IgG from humans attenuates SARS-CoV-2 disease in hamsters

SARS-CoV-2 Spike-specific binding and neutralizing antibodies, elicited either by natural infection or vaccination, have emerged as potential correlates of protection. An important question, however, is whether vaccine-elicited antibodies in humans provide direct, functional protection from SARS-CoV-2 infection and disease. In this study, we explored directly the protective efficacy of human antibodies elicited by Ad26.COV2.S vaccination by adoptive transfer studies. IgG from plasma of Ad26.COV2.S vaccinated individuals was purified and transferred into naïve golden Syrian hamster recipients, followed by intra-nasal challenge of the hamsters with SARS-CoV-2. IgG purified from Ad26.COV2.S-vaccinated individuals provided dose-dependent protection in the recipient hamsters from weight loss following challenge. In contrast, IgG purified from placebo recipients provided no protection in this adoptive transfer model. Attenuation of weight loss correlated with binding and neutralizing antibody titers of the passively transferred IgG. This study suggests that Ad26.COV2.S-elicited antibodies in humans are mechanistically involved in protection against SARS-CoV-2.

One dose of COVID-19 nanoparticle vaccine REVC-128 protects against SARS-CoV-2 challenge at two weeks post-immunization

ABSTRACTA COVID-19 vaccine that can give early protection is needed to eliminate the viral spread efficiently. Here, we demonstrate the development of a nanoparticle vaccine candidate, REVC-128, in which multiple trimeric spike ectodomains with glycine (G) at position 614 were multimerized onto a nanoparticle. In-vitro characterization of this vaccine confirms its structural and antigenic integrity. In-vivo immunogenicity evaluation in mice indicates that a single dose of this vaccine induces potent serum neutralizing antibody titre at two weeks post-immunization. This is significantly higher than titre caused by trimeric spike protein without nanoparticle presentation. The comparison of serum binding to spike subunits between animals immunized by a spike with and without nanoparticle presentation indicates that nanoparticle prefers the display of spike RBD (Receptor-Binding Domain) over S2 subunit, likely resulting in a more neutralizing but less cross-reactive antibody response. Moreover, a Syrian golden hamster in-vivo model for the SARS-CoV-2 virus challenge was implemented two weeks post a single dose of REVC-128 immunization. The results showed that vaccination protects hamsters against the SARS-CoV-2 virus challenge with evidence of steady body weight, suppressed viral loads and alleviation of tissue damage for protected animals, compared with ∼10% weight loss, high viral loads and tissue damage in unprotected animals. Furthermore, the data showed that vaccine REVC-128 is thermostable at up to 37°C for at least 4 weeks. These findings, along with a history of safety for protein vaccines, suggest that the REVC-128 is a safe, stable and efficacious single-shot vaccine to give the earliest protection against SARS-CoV-2 infection.

One dose of COVID-19 nanoparticle vaccine REVC-128 protects against SARS-CoV-2 challenge at two weeks post-immunization

ABSTRACTA COVID-19 vaccine that can give early protection is needed to eliminate the viral spread efficiently. Here, we demonstrate the development of a nanoparticle vaccine candidate, REVC-128, in which multiple trimeric spike ectodomains with glycine (G) at position 614 were multimerized onto a nanoparticle. In-vitro characterization of this vaccine confirms its structural and antigenic integrity. In-vivo immunogenicity evaluation in mice indicates that a single dose of this vaccine induces potent serum neutralizing antibody titre at two weeks post-immunization. This is significantly higher than titre caused by trimeric spike protein without nanoparticle presentation. The comparison of serum binding to spike subunits between animals immunized by a spike with and without nanoparticle presentation indicates that nanoparticle prefers the display of spike RBD (Receptor-Binding Domain) over S2 subunit, likely resulting in a more neutralizing but less cross-reactive antibody response. Moreover, a Syrian golden hamster in-vivo model for the SARS-CoV-2 virus challenge was implemented two weeks post a single dose of REVC-128 immunization. The results showed that vaccination protects hamsters against the SARS-CoV-2 virus challenge with evidence of steady body weight, suppressed viral loads and alleviation of tissue damage for protected animals, compared with ∼10% weight loss, high viral loads and tissue damage in unprotected animals. Furthermore, the data showed that vaccine REVC-128 is thermostable at up to 37°C for at least 4 weeks. These findings, along with a history of safety for protein vaccines, suggest that the REVC-128 is a safe, stable and efficacious single-shot vaccine to give the earliest protection against SARS-CoV-2 infection.

How Organic Waste Improves Bitumen’s Characteristics

The organic fraction derived from the differentiated collection of urban waste is mainly composed of fatty acids, medium molecular weight hydrocarbons and cellulose. This peculiar composition gave us insight into the possible use of organic waste to improve bitumen’s characteristics (possible antioxidant, regenerating and/ or viscosifying additive for road pavements). The issue of the disposal of organic waste is a global one and it’s constantly of increasing concern. This study looks to alleviate this problem by finding ways for this waste fraction to be utilized for the greater good- in this case, as an additive for bitumen binder in road pavements. The present study is focused on the use of waste as it is and waste treated by the FENTON process (treatment with ferrous sulphate and hydrogen peroxide solution). Dynamic Shear Rheology (DSR) and aging tests (Rolling Thin Film Oven Test, RTFOT) showed that two of the additives tested in this study proved effective: one can be utilised as a viscosifying agent and the other can be us ed as a filler.

Immunity elicited by natural infection or Ad26.COV2.S vaccination protects hamsters against SARS-CoV-2 variants of concern

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern have emerged and may pose a threat to both the efficacy of vaccines based on the original WA1/2020 strain and the natural immunity induced by infection with earlier SARS-CoV-2 variants. We investigated how mutations in the spike protein of circulating SARS-CoV-2 variants, which have been shown to partially evade neutralizing antibodies, affect natural and vaccine-induced immunity. We adapted a Syrian hamster model of moderate to severe clinical disease for two variant strains of SARS-CoV-2: B.1.1.7 (alpha variant) and B.1.351 (beta variant). We then assessed the protective efficacy conferred by either natural immunity from WA1/2020 infection or by vaccination with a single dose of the adenovirus serotype 26 vaccine, Ad26.COV2.S. Primary infection with the WA1/2020 strain provided potent protection against weight loss and viral replication in lungs after rechallenge with WA1/2020, B.1.1.7, or B.1.351. Ad26.COV2.S induced cross-reactive binding and neutralizing antibodies that were reduced against the B.1.351 strain compared with WA1/2020 but nevertheless still provided robust protection against B.1.351 challenge, as measured by weight loss and pathology scoring in the lungs. Together, these data support hamsters as a preclinical model to study protection against emerging variants of SARS-CoV-2 conferred by prior infection or vaccination.

A SARS-CoV-2 spike ferritin nanoparticle vaccine protects hamsters against Alpha and Beta virus variant challenge

The emergence of SARS-CoV-2 variants of concern (VOC) requires adequate coverage of vaccine protection. We evaluated whether a SARS-CoV-2 spike ferritin nanoparticle vaccine (SpFN), adjuvanted with the Army Liposomal Formulation QS21 (ALFQ), conferred protection against the Alpha (B.1.1.7), and Beta (B.1.351) VOCs in Syrian golden hamsters. SpFN-ALFQ was administered as either single or double-vaccination (0 and 4 week) regimens, using a high (10 μg) or low (0.2 μg) dose. Animals were intranasally challenged at week 11. Binding antibody responses were comparable between high- and low-dose groups. Neutralizing antibody titers were equivalent against WA1, B.1.1.7, and B.1.351 variants following two high dose vaccinations. Dose-dependent SpFN-ALFQ vaccination protected against SARS-CoV-2-induced disease and viral replication following intranasal B.1.1.7 or B.1.351 challenge, as evidenced by reduced weight loss, lung pathology, and lung and nasal turbinate viral burden. These data support the development of SpFN-ALFQ as a broadly protective, next-generation SARS-CoV-2 vaccine.

mRNA-1273 protects against SARS-CoV-2 beta infection in nonhuman primates

B.1.351 is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant most resistant to antibody neutralization. We demonstrate how the dose and number of immunizations influence protection. Nonhuman primates received two doses of 30 or 100 µg of Moderna's mRNA-1273 vaccine, a single immunization of 30 µg, or no vaccine. Two doses of 100 µg of mRNA-1273 induced 50% inhibitory reciprocal serum dilution neutralizing antibody titers against live SARS-CoV-2 p.Asp614Gly and B.1.351 of 3,300 and 240, respectively. Higher neutralizing responses against B.1.617.2 were also observed after two doses compared to a single dose. After challenge with B.1.351, there was ~4- to 5-log10 reduction of viral subgenomic RNA and low to undetectable replication in bronchoalveolar lavages in the two-dose vaccine groups, with a 1-log10 reduction in nasal swabs in the 100-µg group. These data establish that a two-dose regimen of mRNA-1273 will be critical for providing upper and lower airway protection against major variants of concern.

Engineered SARS-CoV-2 receptor binding domain improves manufacturability in yeast and immunogenicity in mice

Global containment of COVID-19 still requires accessible and affordable vaccines for low- and middle-income countries (LMICs). Recently approved vaccines provide needed interventions, albeit at prices that may limit their global access. Subunit vaccines based on recombinant proteins are suited for large-volume microbial manufacturing to yield billions of doses annually, minimizing their manufacturing cost. These types of vaccines are well-established, proven interventions with multiple safe and efficacious commercial examples. Many vaccine candidates of this type for SARS-CoV-2 rely on sequences containing the receptor-binding domain (RBD), which mediates viral entry to cells via ACE2. Here we report an engineered sequence variant of RBD that exhibits high-yield manufacturability, high-affinity binding to ACE2, and enhanced immunogenicity after a single dose in mice compared to the Wuhan-Hu-1 variant used in current vaccines. Antibodies raised against the engineered protein exhibited heterotypic binding to the RBD from two recently reported SARS-CoV-2 variants of concern (501Y.V1/V2). Presentation of the engineered RBD on a designed virus-like particle (VLP) also reduced weight loss in hamsters upon viral challenge.

Immune correlates of protection by mRNA-1273 vaccine against SARS-CoV-2 in nonhuman primates

Immune correlates of protection can be used as surrogate endpoints for vaccine efficacy. Here, nonhuman primates (NHPs) received either no vaccine or doses ranging from 0.3 to 100 μg of the mRNA-1273 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. mRNA-1273 vaccination elicited circulating and mucosal antibody responses in a dose-dependent manner. Viral replication was significantly reduced in bronchoalveolar lavages and nasal swabs after SARS-CoV-2 challenge in vaccinated animals and most strongly correlated with levels of anti–S antibody and neutralizing activity. Lower antibody levels were needed for reduction of viral replication in the lower airway than in the upper airway. Passive transfer of mRNA-1273–induced immunoglobulin G to naïve hamsters was sufficient to mediate protection. Thus, mRNA-1273 vaccine–induced humoral immune responses are a mechanistic correlate of protection against SARS-CoV-2 in NHPs.

A SARS-CoV-2 spike ferritin nanoparticle vaccine protects against heterologous challenge with B.1.1.7 and B.1.351 virus variants in Syrian golden hamsters

The emergence of SARS-CoV-2 variants of concern (VOC) requires adequate coverage of vaccine protection. We evaluated whether a spike ferritin nanoparticle vaccine (SpFN), adjuvanted with the Army Liposomal Formulation QS21 (ALFQ), conferred protection against the B.1.1.7 and B.1.351 VOCs in Syrian golden hamsters. SpFN-ALFQ was administered as either single or double-vaccination (0 and 4 week) regimens, using a high (10 μg) or low (0.2 μg) immunogen dose. Animals were intranasally challenged at week 11. Binding antibody responses were comparable between high- and low-dose groups. Neutralizing antibody titers were equivalent against WA1, B.1.1.7, and B.1.351 variants following two high dose two vaccinations. SpFN-ALFQ vaccination protected against SARS-CoV-2-induced disease and viral replication following intranasal B.1.1.7 or B.1.351 challenge, as evidenced by reduced weight loss, lung pathology, and lung and nasal turbinate viral burden. These data support the development of SpFN-ALFQ as a broadly protective, next-generation SARS-CoV-2 vaccine.

Evaluation of mRNA-1273 against SARS-CoV-2 B.1.351 Infection in Nonhuman Primates

Background

Vaccine efficacy against the B.1.351 variant following mRNA-1273 vaccination in humans has not been determined. Nonhuman primates (NHP) are a useful model for demonstrating whether mRNA-1273 mediates protection against B.1.351.

Methods

Nonhuman primates received 30 or 100 µg of mRNA-1273 as a prime-boost vaccine at 0 and 4 weeks, a single immunization of 30 µg at week 0, or no vaccine. Antibody and T cell responses were assessed in blood, bronchioalveolar lavages (BAL), and nasal washes. Viral replication in BAL and nasal swabs were determined by qRT-PCR for sgRNA, and histopathology and viral antigen quantification were performed on lung tissue post-challenge.

Results

Eight weeks post-boost, 100 µg x2 of mRNA-1273 induced reciprocal ID ₅₀ neutralizing geometric mean titers against live SARS-CoV-2 D614G and B.1.351 of 3300 and 240, respectively, and 430 and 84 for the 30 µg x2 group. There were no detectable neutralizing antibodies against B.1351 after the single immunization of 30 µg. On day 2 following B.1.351 challenge, sgRNA in BAL was undetectable in 6 of 8 NHP that received 100 µg x2 of mRNA-1273, and there was a ∼2-log reduction in sgRNA in NHP that received two doses of 30 µg compared to controls. In nasal swabs, there was a 1-log ₁₀ reduction observed in the 100 µg x2 group. There was limited inflammation or viral antigen in lungs of vaccinated NHP post-challenge.

Conclusions

Immunization with two doses of mRNA-1273 achieves effective immunity that rapidly controls lower and upper airway viral replication against the B.1.351 variant in NHP.

Immune Correlates of Protection by mRNA-1273 Immunization against SARS-CoV-2 Infection in Nonhuman Primates

Immune correlates of protection can be used as surrogate endpoints for vaccine efficacy. The nonhuman primate (NHP) model of SARS-CoV-2 infection replicates key features of human infection and may be used to define immune correlates of protection following vaccination. Here, NHP received either no vaccine or doses ranging from 0.3 - 100 μg of mRNA-1273, a mRNA vaccine encoding the prefusion-stabilized SARS-CoV-2 spike (S-2P) protein encapsulated in a lipid nanoparticle. mRNA-1273 vaccination elicited robust circulating and mucosal antibody responses in a dose-dependent manner. Viral replication was significantly reduced in bronchoalveolar lavages and nasal swabs following SARS-CoV-2 challenge in vaccinated animals and was most strongly correlated with levels of anti-S antibody binding and neutralizing activity. Consistent with antibodies being a correlate of protection, passive transfer of vaccine-induced IgG to naïve hamsters was sufficient to mediate protection. Taken together, these data show that mRNA-1273 vaccine-induced humoral immune responses are a mechanistic correlate of protection against SARS-CoV-2 infection in NHP.

One-Sentence Summary

mRNA-1273 vaccine-induced antibody responses are a mechanistic correlate of protection against SARS-CoV-2 infection in NHP.

Engineered SARS-CoV-2 receptor binding domain improves immunogenicity in mice and elicits protective immunity in hamsters

Global containment of COVID-19 still requires accessible and affordable vaccines for low- and middle-income countries (LMICs).1 Recently approved vaccines provide needed interventions, albeit at prices that may limit their global access.2 Subunit vaccines based on recombinant proteins are suited for large-volume microbial manufacturing to yield billions of doses annually, minimizing their manufacturing costs.3 These types of vaccines are well-established, proven interventions with multiple safe and efficacious commercial examples.4-6 Many vaccine candidates of this type for SARS-CoV-2 rely on sequences containing the receptor-binding domain (RBD), which mediates viral entry to cells via ACE2.7,8 Here we report an engineered sequence variant of RBD that exhibits high-yield manufacturability, high-affinity binding to ACE2, and enhanced immunogenicity after a single dose in mice compared to the Wuhan-Hu-1 variant used in current vaccines. Antibodies raised against the engineered protein exhibited heterotypic binding to the RBD from two recently reported SARS-CoV-2 variants of concern (501Y.V1/V2). Presentation of the engineered RBD on a designed virus-like particle (VLP) also reduced weight loss in hamsters upon viral challenge.

REGN-COV2 antibodies prevent and treat SARS-CoV-2 infection in rhesus macaques and hamsters

An urgent global quest for effective therapies to prevent and treat coronavirus disease 2019 (COVID-19) is ongoing. We previously described REGN-COV2, a cocktail of two potent neutralizing antibodies (REGN10987 and REGN10933) that targets nonoverlapping epitopes on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. In this report, we evaluate the in vivo efficacy of this antibody cocktail in both rhesus macaques, which may model mild disease, and golden hamsters, which may model more severe disease. We demonstrate that REGN-COV-2 can greatly reduce virus load in the lower and upper airways and decrease virus-induced pathological sequelae when administered prophylactically or therapeutically in rhesus macaques. Similarly, administration in hamsters limits weight loss and decreases lung titers and evidence of pneumonia in the lungs. Our results provide evidence of the therapeutic potential of this antibody cocktail.

Vascular Disease and Thrombosis in SARS-CoV-2-Infected Rhesus Macaques

The COVID-19 pandemic has led to extensive morbidity and mortality throughout the world. Clinical features that drive SARS-CoV-2 pathogenesis in humans include inflammation and thrombosis, but the mechanistic details underlying these processes remain to be determined. In this study, we demonstrate endothelial disruption and vascular thrombosis in histopathologic sections of lungs from both humans and rhesus macaques infected with SARS-CoV-2. To define key molecular pathways associated with SARS-CoV-2 pathogenesis in macaques, we performed transcriptomic analyses of bronchoalveolar lavage and peripheral blood and proteomic analyses of serum. We observed macrophage infiltrates in lung and upregulation of macrophage, complement, platelet activation, thrombosis, and proinflammatory markers, including C-reactive protein, MX1, IL-6, IL-1, IL-8, TNFα, and NF-κB. These results suggest a model in which critical interactions between inflammatory and thrombosis pathways lead to SARS-CoV-2-induced vascular disease. Our findings suggest potential therapeutic targets for COVID-19.

Ad26 vaccine protects against SARS-CoV-2 severe clinical disease in hamsters

Coronavirus disease 2019 (COVID-19) in humans is often a clinically mild illness, but some individuals develop severe pneumonia, respiratory failure and death1-4. Studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in hamsters5-7 and nonhuman primates8-10 have generally reported mild clinical disease, and preclinical SARS-CoV-2 vaccine studies have demonstrated reduction of viral replication in the upper and lower respiratory tracts in nonhuman primates11-13. Here we show that high-dose intranasal SARS-CoV-2 infection in hamsters results in severe clinical disease, including high levels of virus replication in tissues, extensive pneumonia, weight loss and mortality in a subset of animals. A single immunization with an adenovirus serotype 26 vector-based vaccine expressing a stabilized SARS-CoV-2 spike protein elicited binding and neutralizing antibody responses and protected against SARS-CoV-2-induced weight loss, pneumonia and mortality. These data demonstrate vaccine protection against SARS-CoV-2 clinical disease. This model should prove useful for preclinical studies of SARS-CoV-2 vaccines, therapeutics and pathogenesis.

A Single Immunization with Nucleoside-Modified mRNA Vaccines Elicits Strong Cellular and Humoral Immune Responses against SARS-CoV-2 in Mice

SARS-CoV-2 infection has emerged as a serious global pandemic. Because of the high transmissibility of the virus and the high rate of morbidity and mortality associated with COVID-19, developing effective and safe vaccines is a top research priority. Here, we provide a detailed evaluation of the immunogenicity of lipid nanoparticle-encapsulated, nucleoside-modified mRNA (mRNA-LNP) vaccines encoding the full-length SARS-CoV-2 spike protein or the spike receptor binding domain in mice. We demonstrate that a single dose of these vaccines induces strong type 1 CD4⁺ and CD8⁺ T cell responses, as well as long-lived plasma and memory B cell responses. Additionally, we detect robust and sustained neutralizing antibody responses and the antibodies elicited by nucleoside-modified mRNA vaccines do not show antibody-dependent enhancement of infection in vitro. Our findings suggest that the nucleoside-modified mRNA-LNP vaccine platform can induce robust immune responses and is a promising candidate to combat COVID-19.

Analysis of Mechanical Performance of Bitumen Modified with Waste Plastic and Rubber Additives by Rheology and Self Diffusion NMR Experiments

In this study, the mechanical and physico-chemical properties of a new kind of modified bitumen are presented. The bituminous binders have been modified in order to understand the effect on the structural properties of several compounds such as a Polymer elastomer as Styrene Butadiene Rubber (SBR), Polymer thermoplastic polypropylene (PP) and a waste plastic (Waste PP). Laboratory tests have been focused on the characterization of bitumen modified with single product and their binary combinations compared with pristine binder as a reference. Characterization has been conducted by using conventional as well as advanced methods on bitumens. Fundamental rheological tests, based on dynamic shear rheometer in the temperature range from -30 °C to +160 °C have been performed and the structure of a bitumens and modified bitumens has been analysed by the mobility of the oily maltene by self-diffusion Pulsed field gradient spin-echo (PGSE) FT-NMR experiments.

Predicting birth weight in fetuses with gastroschisis

OBJECTIVE

To determine the accuracy of commonly utilized ultrasound formulas for estimating birth weight (BW) in fetuses with gastroschisis.

STUDY DESIGN

A retrospective review was conducted of all inborn pregnancies with gastroschisis within the five institutions of the University of California Fetal Consortium (UCfC) between 2007 and 2012. Infants delivered at ⩾28 weeks who had an ultrasound within 21 days before delivery were included. Prediction of BW was evaluated for each of the five ultrasound formulas: Hadlock 1 (abdominal circumference (AC), biparietal diameter (BPD), femur length (FL) and head circumference (HC)) and Hadlock 2 (AC, BPD and FL), Shepard (AC and BPD), Honarvar (FL) and Siemer (BPD, occipitofrontal diameter (OFD), and FL) using Pearson's correlation, mean difference and percent error and Bland-Altman analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the ultrasound diagnosis of intrauterine growth restriction (IUGR) were assessed.

RESULTS

We identified 191 neonates born with gastroschisis within the UCfC, with 111 neonates meeting the inclusion criteria. The mean gestational age at delivery was 36.3±1.7 weeks and the mean BW was 2448±460 g. Hadlock (1) formula was found to have the best correlation (r=0.81), the lowest mean difference (8±306 g) and the lowest mean percent error (1.4±13%). The Honarvar and Siemer formulas performed significantly worse when compared with Hadlock 1, with a 13.7% (P<0.001) and 3.9% (P=0.03) difference, respectively, between estimated and actual BW. This was supported by Bland-Altman plots. For Hadlock 1 and 2, sensitivity was 80% with a NPV of 91%.

CONCLUSION

The widely used Hadlock (1) and (2) formulas provided the best estimated BW in infants with gastroschisis despite its inclusion of abdominal circumference. Furthermore, this formula performs well with diagnosis of IUGR.

Fraction of high-grade cervical intraepithelial lesions attributable to genotypes targeted by a nonavalent HPV vaccine in Galicia, Spain

Background

Human papillomavirus (HPV) bivalent and quadrivalent vaccines have been widely implemented in worldwide organized immunization programs. A nonavalent HPV vaccine is now available in several countries. The objective was to describe the fraction of squamous non-invasive high-grade cervical intraepithelial lesions attributable to genotypes targeted by bi-quadrivalent vaccines and by nonavalent vaccine according to age and diagnosis in women living in the city of Vigo (Galicia, Spain).

Methods

Cervical scrapings (2009–2014) of women with histological diagnosis of cervical intraepithelial neoplasia grade 2 (CIN2, n = 145) and grade 3-carcinoma in situ (CIN3-CIS, n = 244) were tested with Linear Array HPV Genotyping test (Roche diagnostics, Mannheim, Germany). Hierarchical estimation of the fraction attributable to HPV 16/18 or HPV 31/33/45/52/58 detected alone or in combination was calculated. Absolute additional fraction attributable to genotypes targeted by nonavalent vaccine compared to genotypes targeted by bi-quadrivalent vaccines was calculated as the increment of attributable cases with respect to all studied cases. Age group 1, 2 and 3 included women 18 to 34, 35–44 and ≥45 years old, respectively. EPIDAT 3.1 was used.

Results

Fraction attributable to genotypes targeted by bi-quadrivalent vaccines was 59% CIN2 vs. 69% CIN3-CIS (p < 0.001). It was 63/51/50% of CIN2 and 78/66/45% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by nonavalent vaccine was 86% CIN2 and 86% CIN3-CIS. It was 87/91/75% of CIN2 and 90/86/76% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by these vaccines tended to decrease as age increased (p-trend <0.05). Globally, absolute additional attributable fraction was 16%, 26% and 29% in age group 1, 2 and 3, respectively (p < 0.005).

Conclusions

Absolute additional fraction of CIN2 and CIN3-CIS attributable to genotypes targeted by nonavalent vaccine was observed in women of any age, especially in those over 35 years old.

Morfologia macroscópica do aparelho reprodutor feminino de Leontopithecus cativos (Lesson, 1840) Primates-Callitrichidae

Descreveu-se o sistema reprodutor feminino em três espécies de mico-leão Leontopithecus (Lesson 1840), cativos: L. rosalia, L. chrysopygus e L. chrysomelas. A vulva está delimitada pelos lábios vulvares menores e com clitóris conspícuo. A superfície do períneo urogenital apresenta elevações papilares mais concentradas nos lábios vulvares, conferindo-lhe aspecto rugoso. O vestíbulo vaginal constitui um tubo muscular de parede espessa que se estende da rima da vulva até o óstio da vagina. A vagina é um tubo muscular alongado e achatado dorsoventralmente, que comunica o vestíbulo vaginal ao colo uterino. O útero piriforme está localizado na porção caudal da cavidade abdominal. Craniolateralmente abrem-se tubas uterinas convolutas e ovários grosseiramente fusiformes de superfície lisa.

Mesoscale engines by nonlinear friction

A new approach to build mesoscopic-size engines that move translationally or rotationally and can perform useful functions such as the pulling of a cargo is presented. The approach is based on the transformation of internal vibrations of the moving object into directed motion, making use of the nonlinear properties of friction. This can be achieved by superimposing time-dependent external fields that break the spatial symmetry. The motion can be controlled and optimized by adjusting the system parameters.

Rectification by hopping motion through nonsymmetric potentials: local versus global bias

The hopping motion of noninteracting classical particles through nonsymmetric potentials is investigated in the case of alternating local bias. Different to the case of alternating global bias, a resonancelike behavior is observed. The system exhibits rectification effects in the regime of small to medium bias, whereas rectification effects are absent in the strong bias regime. Possible generalizations and applications are outlined.

Self-generated power-law tails in probability distributions

We consider random processes characterized by the presence of correlations in their variance, or more generally in some of their moments. Typical examples are constituted by autoregressive conditional heteroskedasticity (ARCH) processes which are known to display power-law tails in the associated probability distributions. Here, we determine the corresponding exponents exactly and extend these results to relaxation phenomena which can be expected to play a role in natural sciences.

Molecular motor based entirely on the Coulomb interaction

A molecular motor is introduced which is composed of charges only and which does not contain any potential or interaction besides the Coulomb one. The motor is shown to transform efficiently a driven random rotation into a directed translational motion. The direction of translational motion can be chosen dynamically, so that a "forward gear," a "reverse gear," and even a "neutral gear" exist. The high efficiency stems from the fact that this motor only steps in the direction determined by the chosen gear.

"Generalized des Cloizeaux" exponent for self-avoiding walks on the incipient percolation cluster

We study the asymptotic shape of self-avoiding random walks (SAW) on the backbone of the incipient percolation cluster in d-dimensional lattices analytically. It is generally accepted that the configurational averaged probability distribution function <P(B)(r,N)> for the end-to-end distance r of an N step SAW behaves as a power law for r-->0. In this work, we determine the corresponding exponent using scaling arguments, and show that our suggested "generalized des Cloizeaux" expression for the exponent is in excellent agreement with exact enumeration results in two and three dimensions.

Pregnancy outcome in Hispanic patients with unexplained positive triple marker screening for Down syndrome

OBJECTIVE

The objective of this study was to compare pregnancy outcomes in Hispanic patients with a positive serum triple marker screen for Down syndrome and normal fetal karyotype with Hispanic women who had a negative triple marker screen.

METHODS

This prospective investigation involved Hispanic gravidas who underwent maternal serum screening. A power analysis was performed to determine the sample size. Fifty women with false-positive screens for Down syndrome were matched with a control group of 100 women with a negative screen. Adverse pregnancy outcomes were compared between the two groups.

RESULTS

An adverse pregnancy outcome occurred in 14% of the study group and in 13% of controls. There were no statistically significant differences between the two groups in the incidence of preterm labor (p > 0.5), pre-eclampsia (p > 0.1), intrauterine growth restriction (p > 0.5), or fetal demise (p > 0.5).

CONCLUSION

Hispanic patients with unexplained positive triple marker screen for Down syndrome do not appear to be at increased risk for adverse pregnancy outcomes.

Molecular motor that never steps backwards

We investigate the dynamics of a classical particle in a one-dimensional two-wave potential composed of two periodic potentials that are time independent and of the same amplitude and periodicity. One of the periodic potentials is externally driven and performs a translational motion with respect to the other. It is shown that, if one of the potentials is of the ratchet type, translation of the potential in a given direction leads to motion of the particle in the same direction, whereas translation in the opposite direction leaves the particle localized at its original location. Moreover, even if the translation is random, but still has a finite velocity, an efficient directed transport of the particle occurs.

Critical packing fraction of rectangular particles on the square lattice

The random packing of identical and nonoverlapping rectangular particles of size nxm (1</=n,m</=10) is studied numerically on the square lattice, and the corresponding packing fractions p(f) and percolation probabilities P(infinity) are determined. We find that for randomly oriented particles there is a critical packing fraction p(c)(f)=0.67+/-0.01, such that for all particles sizes nxm for which p(f)<p(c)(f) they do not percolate, i.e., P(infinity)-->0 for L-->infinity, while when p(f)>p(c)(f),P(infinity)-->1 when L-->infinity and an infinite cluster exists. The value for p(c)(f) is found to be consistent with the continuum percolation threshold p(c) congruent with0.67 for overlapping particles in two dimensions.

Atomic scale engines: cars and wheels

We introduce a new approach to build microscopic engines on the atomic scale that move translationally or rotationally and can perform useful functions such as the pulling of a cargo. Characteristic of these engines is the possibility to determine dynamically the directionality of the motion. The approach is based on the transformation of the fed energy to directed motion through a dynamical competition between the intrinsic lengths of the moving object and the supporting carrier.

Multifractal behavior of linear polymers in disordered media

The scaling behavior of linear polymers in disordered media modeled by self-avoiding random walks (SAWs) on the backbone of two- and three-dimensional percolation clusters at their critical concentrations p(c) is studied. All possible SAW configurations of N steps on a single backbone configuration are enumerated exactly. We find that the moments of order q of the total number of SAWs obtained by averaging over many backbone configurations display multifractal behavior; i.e., different moments are dominated by different subsets of the backbone. This leads to generalized coordination numbers mu(q) and enhancement exponents gamma(q), which depend on q. Our numerical results suggest that the relation mu(1)=p(c)mu between the first moment mu(1) and its regular lattice counterpart mu is valid.

Corticotrophin-releasing hormone and fetal responses in human pregnancy

During human pregnancy, maternal and fetal compartments of the human placenta produce and release corticotrophic-releasing hormone (CRH). Elevations of placental CRH are associated with decreased gestational length (including preterm delivery). The effects of elevated placental CRH on human fetal neurological development are not known. Pregnant women in the 31st and 32nd week of gestation consented to procedures for collection of blood and measurement of fetal heart rate (FHR) in response to a series of 40 vibro-acoustic stimuli (VAS). Measures of habituation and dishabituation were calculated from the FHR. All subjects were followed to delivery. Fetuses (N = 33) of women with highly elevated CRH were least responsive (p < .03) to stimulation after presentation of a novel (dishabituating) stimulus with control for parity, fetal gender, medical (antepartum) risk, and gestational length at term. In a larger sample (N = 156) a polynomial model predicted the pattern of FHR reactivity for the first 15 trials. Placental CRH concentration significantly predicted FHR reactivity after controlling for the effects of trial number, baseline FHR, inter-trial interval, and presence of uterine contractions. Increased maternal CRH levels were significantly related to the length of gestation after controlling for the effects of fetal gender, parity, and medical risk (p = .05). The relationship between length of gestation and FHR was not significant suggesting separate actions of CRH on these events. Elevated placental CRH appears to accelerate certain developmental events (gestational length) and may influence the fetal nervous system. The impaired fetal responses to novelty and increased arousal observed in this study suggest that neurological systems may be targets for placental CRH during sensitive developmental periods.

Influence of dipolar interaction on magnetic properties of ultrafine ferromagnetic particles

We use Monte Carlo simulations to study the influence of dipolar interaction and polydispersity on the magnetic properties of single-domain ultrafine ferromagnetic particles. From the zero field cooling (ZFC)/field cooling (FC) simulations we observe that the blocking temperature T(B) clearly increases with increasing strength of interaction, but it is almost not effected by a broadening of the distribution of particle sizes. While the dependence of the ZFC/FC curves on interaction and cooling rate are reminiscent of a spin glass transition at T(B), the relaxational behavior of the magnetic moments below T(B) is not in accordance with the picture of cooperative freezing.

Optimal paths in disordered media: scaling of the crossover from self-similar to self-affine behavior

We study optimal paths in disordered energy landscapes using energy distributions of the type P(log(10) E)=const that lead to the strong disorder limit. If we truncate the distribution, so that P(log(10) E)=const only for E(min) < or =E < or =E(max), and P(log(10) E)=0 otherwise, we obtain a crossover from self-similar (strong disorder) to self-affine (moderate disorder) behavior at a path length l(x). We find that l(x) proportional, variant[log(10)(E(max)/E(min))](kappa), where the exponent kappa has the value kappa=1.60 +/- 0.03 both in d=2 and d=3. We show how the crossover can be understood from the distribution of local energies on the optimal paths.

The incidence and severity of shoulder dystocia correlates with a sonographic measurement of asymmetry in patients with diabetes

The objective of this paper is to examine the relationship between fetal asymmetry measured sonographically and the incidence and severity of shoulder dystocia in diabetic patients. Ultrasound data were collected retrospectively from examinations of women with gestational and pregastational diabetes who delivered at University of California, Irvine Medical Center from 1993-1995. Sonographic fetal asymmetry was quantified by calculating the difference between the abdominal diameter and the biparietal diameter in centimeters (AD-BPD). The residual AD-BPD was a patient's actual AD-BPD at the time of the ultrasound minus the mean AD-BPD obtained in our population at the patient's gestational age. The correlations between fetal asymmetry and the incidence and severity of shoulder dystocia were assessed using an analysis of variance as well as a logistic regression analysis. Mild shoulder dystocia was defined as a delivery requiring McRobert's maneuver and/or suprapubic pressure, while severe shoulder dystocia was assessed when delivery of the posterior arm with Wood's corkscrew maneuver was required. One hundred twenty-three women met the inclusion criteria for the study. Dividing the cohort into three groups based on AD-BPD residual values resulted in the following AD-BPD residual ranges and incidences of shoulder dystocia: Group I, -1.80 to -0.32 cm (9.8%), Group II, -0.31 to 0.32 cm (19.5%), and Group III .33 to 2.0 cm (34.1%), (p <0.03). The residual AD-BPD difference correlated with the incidence of shoulder dystocia after controlling for maternal age, weight, parity, birth weight, and the gestational age at ultrasound (P <0.03). Similar results were found with regards to dystocia severity as the mean residual AD-BPD difference between those with no dystocia, mild dystocia, and severe shoulder dystocia was -0.09, 0.23, and 0.46 cm, respectively, (p <0.006). The residual AD-BPD correlated with the severity of shoulder dystocia after controlling for the above-mentioned confounding variables (p <0.05) in a regression analysis. There is a direct correlation in diabetic patients between the level of fetal truncal asymmetry measured sonographically and the incidence and severity of shoulder dystocia.

Maternal corticotropin-releasing hormone and habituation in the human fetus

Elevated concentrations of maternal corticotrophin-releasing hormone (CRH) during the 2nd and early 3rd trimester of human pregnancy are associated with spontaneous preterm birth, but the effects of maternal CRH on the fetus are unknown. Maternal plasma was collected for analysis of CRH concentration, m = 156.24 +/- 130.91 pg/ml, from 33 pregnant women during Weeks 31-33 of gestation. Immediately after collection of plasma, fetal heart rate (FHR) measures were obtained in response to a challenge with a series of vibroacoustic stimuli. Fetuses of mothers with highly elevated CRH did not respond significantly to the presence of a novel stimulus in a repeated series, p = 0.016. These effects on the FHR response were not related to parity, fetal gender, medical (antepartum) risk, or eventual birth outcomes. Impaired dishabituation in these fetuses of mothers with high concentrations of CRH suggests that neurological systems rich with CRH receptors that support learning and memory, such as parahippocampal regions, may be targets for maternal/placental CRH, with implications for fetal neurological development.

Pregnancy in a Jehovah's witness with cervical cancer and anemia

A 34-year-old Jehovah's Witness presented with vaginal bleeding and anemia at 23 weeks gestation. She was diagnosed with a FIGO Stage IB2 squamous cell carcinoma of the cervix. The patient refused transfusion of blood products and strongly desired to continue the pregnancy. She was hospitalized and at 33 weeks gestation underwent a Cesarean-radical hysterectomy with measures that minimized blood loss.