Immunogenicity and safety of a bivalent (omicron BA.5 plus ancestral) SARS-CoV-2 recombinant spike protein vaccine as a heterologous booster dose: interim analysis of a phase 3, non-inferiority, randomised, clinical trial

BACKGROUND

SARS-CoV-2 variants evade immunity despite vaccination with prototype COVID-19 vaccines or previous infection. The 2019nCoV-311 (part 2) study is evaluating immune responses after two booster doses of a vaccine containing the omicron BA.5 subvariant spike protein in adults previously vaccinated with a prototype mRNA vaccine. This interim analysis reports on day 28 immunogenicity and safety outcomes after one booster dose.

METHODS

In this phase 3, randomised, observer-blinded study conducted at 35 sites in Australia, medically stable, previously COVID-19-vaccinated (mRNA-based; ≥three doses) adults aged 18 years or older were enrolled and randomly allocated (1:1:1; via an interactive web response system) to receive two doses of bivalent (NVX-CoV2373 + NVX-CoV2540; bivalent group), authorised prototype (NVX-CoV2373; prototype group), or BA.5 (NVX-CoV2540; BA.5 group) vaccine. Only blinded personnel performed study assessments or had participant contact to collect data after study vaccination. Participants received vaccines containing 5 μg SARS-CoV-2 recombinant spike protein and 50 μg Matrix-M adjuvant, administered via a 0·5 mL intramuscular injection (2·5 μg of NVX-CoV2373 plus 2·5 μg of NVX-CoV2540 for the bivalent vaccine, prepared on-site as a 1:1 mixture). The coprimary endpoints include day 28 neutralising antibody geometric mean titre (GMT) ratios (GMTRs) to omicron BA.5 and the ancestral strain, and seroresponse rates to BA.5, in the bivalent and prototype groups. These endpoints were calculated in the per-protocol analysis set, which was defined as participants who had received a vaccine dose, had baseline and day 28 immunogenicity data, and were PCR-negative for SARS-CoV-2, with no major protocol deviations. The primary objective was to determine the primary outcome (antibody responses), which consisted of three comparisons: superiority of the bivalent versus prototype vaccine for neutralising antibody GMT to BA.5 (ie, lower bound of the GMTR 95% CI >1·0); non-inferiority of neutralising antibody seroresponse rate to BA.5 (ie, lower bound of the seroresponse rate 95% CI >-5%); and non-inferiority of neutralising antibody GMT to the ancestral strain (ie, lower bound of GMTR 95% CI >0·67). This trial was registered at ClinicalTrials.gov, number NCT05372588.

FINDINGS

Between March 22, 2023 and May 2, 2023, 837 participants were screened for eligibility and 766 were randomly allocated to receive the BA.5 (n=255), prototype (n=252), or bivalent (n=259) vaccine. After accounting for exclusions due to participants being baseline SARS-CoV-2-positive, having previous infection, or protocol deviations, the per-protocol analysis set included 694 participants (236 in BA.5 group, 227 in prototype group, and 231 in bivalent group). In this interim analysis (maximum follow-up 35 days after the first dose), the bivalent group, compared with the prototype group, had superior neutralising antibody responses to BA.5 (GMT 1017·8 [95% CI 891·0-1162·6] vs 515·1 [450·4-589·0]; GMTR 2·0 [1·69-2·33]) and a non-inferior seroresponse rate to BA.5 at day 28 (39·8% [33·5-46·5] vs 12·3% [8·4-17·3]; difference 27·5% [19·8-35·0]). The bivalent group also had non-inferior neutralising antibody responses to the ancestral strain (GMTR 1·0 [0·84-1·20]), compared with the prototype group. All vaccines were similarly well tolerated.

INTERPRETATION

All three coprimary endpoints were met in part 2 of the ongoing 2019nCoV-311 study. These data support the development of monovalent and/or bivalent vaccines for the most currently circulating variants, to optimise protection. With no new safety findings, further investigation of omicron-based subvariant vaccines is supported by the evidence.

FUNDING

Novavax.

First Measurement of η Meson Production in Neutrino Interactions on Argon with MicroBooNE

We present a measurement of η production from neutrino interactions on argon with the MicroBooNE detector. The modeling of resonant neutrino interactions on argon is a critical aspect of the neutrino oscillation physics program being carried out by the DUNE and Short Baseline Neutrino programs. η production in neutrino interactions provides a powerful new probe of resonant interactions, complementary to pion channels, and is particularly suited to the study of higher-order resonances beyond the Δ(1232). We measure a flux-integrated cross section for neutrino-induced η production on argon of 3.22±0.84(stat)±0.86(syst) 10^{-41}  cm^{2}/nucleon. By demonstrating the successful reconstruction of the two photons resulting from η production, this analysis enables a novel calibration technique for electromagnetic showers in GeV accelerator neutrino experiments.

Prototype and BA.5 protein nanoparticle vaccines protect against Omicron BA.5 variant in Syrian hamsters

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with greater transmissibility or immune evasion properties has jeopardized the existing vaccine and antibody-based countermeasures. Here, we evaluated the efficacy of boosting pre-immune hamsters with protein nanoparticle vaccines (Novavax, Inc.) containing recombinant Prototype (Wuhan-1) or BA.5 S proteins against a challenge with the Omicron BA.5 variant of SARS-CoV-2. Serum antibody binding and neutralization titers were quantified before challenge, and viral loads were measured 3 days after challenge. Boosting with Prototype or BA.5 vaccine induced similar antibody binding responses against ancestral Wuhan-1 or BA.5 S proteins, and neutralizing activity of Omicron BA.1 and BA.5 variants. One and three months after vaccine boosting, hamsters were challenged with the Omicron BA.5 variant. Prototype and BA.5 vaccine-boosted hamsters had reduced viral infection in the nasal washes, nasal turbinates, and lungs compared to unvaccinated animals. Although no significant differences in virus load were detected between the Prototype and BA.5 vaccine-boosted animals, fewer breakthrough infections were detected in the BA.5-vaccinated hamsters. Thus, immunity induced by Prototype or BA.5 S protein nanoparticle vaccine boosting can protect against the Omicron BA.5 variant in the Syrian hamster model.

IMPORTANCE

As SARS-CoV-2 continues to evolve, there may be a need to update the vaccines to match the newly emerging variants. Here, we compared the protective efficacy of the updated BA.5 and the original Wuhan-1 COVID-19 vaccine against a challenge with the BA.5 Omicron variant of SARS-CoV-2 in hamsters. Both vaccines induced similar levels of neutralizing antibodies against multiple variants of SARS-CoV-2. One and three months after the final immunization, hamsters were challenged with BA.5. No differences in protection against the BA.5 variant virus were observed between the two vaccines, although fewer breakthrough infections were detected in the BA.5-vaccinated hamsters. Together, our data show that both protein nanoparticle vaccines are effective against the BA.5 variant of SARS-CoV-2 but given the increased number of breakthrough infections and continued evolution, it is important to update the COVID-19 vaccine for long-term protection.

The parent and family impact of CLN3 disease: an observational survey-based study

BACKGROUND

CLN3 disease (also known as CLN3 Batten disease or Juvenile Neuronal Ceroid Lipofuscinosis) is a rare pediatric neurodegenerative disorder caused by biallelic mutations in CLN3. While extensive efforts have been undertaken to understand CLN3 disease etiology, pathology, and clinical progression, little is known about the impact of CLN3 disease on parents and caregivers. Here, we investigated CLN3 disease progression, clinical care, and family experiences using semi-structured interviews with 39 parents of individuals with CLN3 disease. Analysis included response categorization by independent observers and quantitative methods.

RESULTS

Parents reported patterns of disease progression that aligned with previous reports. Insomnia and thought- and mood-related concerns were reported frequently. "Decline in visual acuity" was the first sign/symptom noticed by n = 28 parents (70%). A minority of parents reported "behavioral issues" (n = 5, 12.5%), "communication issues" (n = 3, 7.5%), "cognitive decline" (n = 1, 2.5%), or "seizures" (n = 1, 2.5%) as the first sign/symptom. The mean time from the first signs or symptoms to a diagnosis of CLN3 disease was 2.8 years (SD = 4.1). Misdiagnosis was common, being reported by n = 24 participants (55.8%). Diagnostic tests and treatments were closely aligned with observed symptoms. Desires for improved or stabilized vision (top therapeutic treatment concern for n = 14, 32.6%), cognition (n = 8, 18.6%), and mobility (n = 3, 7%) dominated parental concerns and wishes for therapeutic correction. Family impacts were common, with n = 34 (81%) of respondents reporting a financial impact on the family and n = 20 (46.5%) reporting marital strain related to the disease.

CONCLUSIONS

Collectively, responses demonstrated clear patterns of disease progression, a strong desire for therapies to treat symptoms related to vision and cognition, and a powerful family impact driven by the unrelenting nature of disease progression.

Immunogenicity and efficacy of XBB.1.5 rS vaccine against EG.5.1 variant of SARS-CoV-2 in Syrian hamsters

The continued emergence of SARS-CoV-2 variants necessitates updating COVID-19 vaccines to match circulating strains. The immunogenicity and efficacy of these vaccines must be tested in pre-clinical animal models. In Syrian hamsters, we measured the humoral and cellular immune response after immunization with the nanoparticle recombinant Spike (S) protein-based COVID-19 vaccine (Novavax, Inc.). We also compared the efficacy of the updated monovalent XBB.1.5 variant vaccine to previous COVID-19 vaccines for the induction of XBB.1.5 and EG.5.1 neutralizing antibodies and protection against a challenge with the EG.5.1 variant of SARS-CoV-2. Immunization induced high levels of spike-specific serum IgG and IgA antibodies, S-specific IgG and IgA antibody secreting cells, and antigen specific CD4 + T-cells. The XBB.1.5 and XBB.1.16 vaccines, but not the Prototype vaccine, induced high levels of neutralizing antibodies against XBB.1.5 and EG.5.1 variants of SARS-CoV-2. Upon challenge with the Omicron EG.5.1 variant, the XBB.1.5 and XBB.1.16 vaccines reduced the virus load in the lungs, nasal turbinates, trachea and nasal washes. The bivalent vaccine continued to offer protection in the trachea and lungs, but protection was reduced in the upper airways. In contrast, the monovalent Prototype vaccine no longer offered good protection, and breakthrough infections were observed in all animals and tissues. Thus, the protein-based XBB.1.5 vaccine is immunogenic and can protect against the Omicron EG.5.1 variant in the Syrian hamster model.

Unintended consequences of using collars with occipital extensions in neck support - Snapshot assessment at the largest tertiary spinal referral centre in the UK

INTRODUCTION

Upper cervical spine fractures are commonplace in the elderly following low energy trauma. These injuries carry high mortality rates, similar to patients sustaining hip fractures. A key aspect affecting clinical outcome is effective management in the first 12 weeks following injury. This study aims to assess the understanding of healthcare staff that may be required to care for such patients.

MATERIALS AND METHODS

A survey was carried out over a single day at the UK's largest Spine Specialist referral centre (Salford Royal Foundation Trust, SRFT) assessing the understanding of healthcare staff of the term, 'Collar with occipital extension', by asking staff to identify the safe position of the neck when looking at clinical images of a model in a collar in various different neck positions. The participants demographics were then taken, including profession, grade, spinal/post graduate experience, if English is their first language and their understanding of the term 'Collar with occipital extension'.

RESULTS

102 participants were interviewed and the results showed almost half (45.1%) of participants selecting an incorrect hyperextended neck to be a safe position for conservative treatment and only 37.3% selecting the neutral position as satisfactory. The only positive predictors identified for those selective the neutral safe cervical spine alignment was if participants had >5 years of previous spinal experience (p = 0.0006) or if they understood the term 'Collar with occipital extension' to be describing the collar component (p = 0.000013) and not neck position.

CONCLUSION

Management of spinal injuries are classically poorly managed in non-spinal centres, possibly due to the lack of training and understanding within the spinal speciality. This study shows the importance of clearly communicating with referring hospitals exactly how to conservatively manage patients with high cervical injuries to best improve clinical outcome.

Ischemia but no obstructive coronary artery disease: more than meets the eye

Symptomatic women with angina are more likely to have ischemia with no obstructive coronary arteries (INOCA) compared to men. In both men and women, the finding of INOCA is not benign and is associated with adverse cardiovascular events, including myocardial infarction, heart failure and angina hospitalizations. Women with INOCA have more angina and a lower quality of life compared to men, but they are often falsely reassured because of a lack of obstructive coronary artery disease (CAD) and a perception of low risk. Coronary microvascular dysfunction (CMD) is a key pathophysiologic contributor to INOCA, and non-invasive imaging methods are used to detect impaired microvascular flow. Coronary vasospasm is another mechanism of INOCA, and can co-exist with CMD, but usually requires invasive coronary function testing (CFT) with provocation testing for a definitive diagnosis. In addition to traditional heart disease risk factors, inflammatory, hormonal and psychological risk factors that impact microvascular tone are implicated in INOCA. Treatment of risk factors and use of anti-atherosclerotic and anti-anginal medications offer benefit. Increasing awareness and early referral to specialized centers that focus on INOCA management can improve patient-oriented outcomes. However, large, randomized treatment trials to investigate the impact on major adverse cardiovascular events (MACE) are needed. In this focused review, we discuss the prevalence, pathophysiology, presentation, diagnosis and treatment of INOCA.

Search for Heavy Neutral Leptons in Electron-Positron and Neutral-Pion Final States with the MicroBooNE Detector

We present the first search for heavy neutral leptons (HNLs) decaying into νe^{+}e^{-} or νπ^{0} final states in a liquid-argon time projection chamber using data collected with the MicroBooNE detector. The data were recorded synchronously with the NuMI neutrino beam from Fermilab's main injector corresponding to a total exposure of 7.01×10^{20} protons on target. We set upper limits at the 90% confidence level on the mixing parameter |U_{μ4}|^{2} in the mass ranges 10≤m_{HNL}≤150  MeV for the νe^{+}e^{-} channel and 150≤m_{HNL}≤245  MeV for the νπ^{0} channel, assuming |U_{e4}|^{2}=|U_{τ4}|^{2}=0. These limits represent the most stringent constraints in the mass range 35 Collapse

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Three immunizations with Novavax's protein vaccines increase antibody breadth and provide durable protection from SARS-CoV-2

The immune responses to Novavax's licensed NVX-CoV2373 nanoparticle Spike protein vaccine against SARS-CoV-2 remain incompletely understood. Here, we show in rhesus macaques that immunization with Matrix-MTM adjuvanted vaccines predominantly elicits immune events in local tissues with little spillover to the periphery. A third dose of an updated vaccine based on the Gamma (P.1) variant 7 months after two immunizations with licensed NVX-CoV2373 resulted in significant enhancement of anti-spike antibody titers and antibody breadth including neutralization of forward drift Omicron variants. The third immunization expanded the Spike-specific memory B cell pool, induced significant somatic hypermutation, and increased serum antibody avidity, indicating considerable affinity maturation. Seven months after immunization, vaccinated animals controlled infection by either WA-1 or P.1 strain, mediated by rapid anamnestic antibody and T cell responses in the lungs. In conclusion, a third immunization with an adjuvanted, low-dose recombinant protein vaccine significantly improved the quality of B cell responses, enhanced antibody breadth, and provided durable protection against SARS-CoV-2 challenge.

Patterns of online information use prior to middle-ear surgery: a retrospective cohort study

OBJECTIVE

This study aimed to identify what proportion of middle-ear surgery patients utilise the internet for information and to characterise which resources and media formats are used and for what durations.

METHOD

A single-arm, retrospective cohort study was performed using an online survey of English-speaking patients who underwent middle-ear surgery over a three-year period across two otology practices.

RESULTS

Of 260 invitees, 165 responded. A total of 122 used online resources: 9.8 per cent used online resources for less than 15 minutes, 27.0 per cent used them for 15 to 29 minutes, 27.0 per cent used them for 30 to 59 minutes and 36.1 per cent used them for 60 minutes or more. Of online users with complete responses (108 of 122), the most used resources (used for 12 minutes or more) were: written information (73.1 per cent); surgeons' websites (55.6 per cent); pictures, diagrams or photos (42.6 per cent); videos (37.0 per cent); and social media (10.2 per cent).

CONCLUSION

At least 46.9 per cent of patients undergoing elective ear surgery use online resources. Most time is spent using written information, pictures, diagrams, photos and videos. Therefore, it is increasingly essential that accurate and informative resources in these formats are readily available online.

Diet-induced obesity and diabetes enhance mortality and reduce vaccine efficacy for SARS-CoV-2

IMPORTANCE

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a wide spectrum of diseases in the human population, from asymptomatic infections to death. It is important to study the host differences that may alter the pathogenesis of this virus. One clinical finding in coronavirus disease 2019 (COVID-19) patients is that people with obesity or diabetes are at increased risk of severe illness from SARS-CoV-2 infection. We used a high-fat diet model in mice to study the effects of obesity and type 2 diabetes on SARS-CoV-2 infection as well as how these comorbidities alter the response to vaccination. We find that diabetic/obese mice have increased disease after SARS-CoV-2 infection and they have slower clearance of the virus. We find that the lungs of these mice have increased neutrophils and that removing these neutrophils protects diabetic/obese mice from disease. This demonstrates why these diseases have increased risk of severe disease and suggests specific interventions upon infection.

Attitudes and barriers to participation in window-of-opportunity trials reported by White and Asian/Asian British ethnicity patients who have undergone treatment for endometrial cancer

PURPOSE

Window-of-opportunity trials (WOT) are a study design that have been used to investigate drug activity in endometrial cancer (EC). Recruitment to cancer clinical trials by patients from ethnic minority groups is reported to be lower than for patients of White ethnicity.

METHODS

A verbal questionnaire was conducted with White and Asian/Asian British ethnicity patients who had undergone treatment for EC. Strategic purposeful sampling was used to recruit patients from diverse social/educational backgrounds. Questions explored: background knowledge of clinical research, WOT study design, and views on medications that might be investigated. Thematic analysis was used to explore motivations for WOT participation and perceived barriers.

RESULTS

In total, 21 patients were recruited to the study (15 White and 6 Asian/Asian British). Views on optimum time to receive trial information differed, preferences ranging from 'at the time of diagnosis' to 'a few days after diagnosis'. The choice of medication under investigation had a strong influence on potential willingness to participate, with greater interest reported in medications derived from vitamins or food supplements rather than hormone-based drugs. Potential barriers to participation included concern over potential side-effects and the emotional/physical burden of a cancer diagnosis prior to major surgery.

DISCUSSION

This study provides important insights into patients' views on WOT participation in EC and raises issues that need to be considered for future trial design and participant recruitment materials. The timing and format of study information and type of substance under investigation were factors influencing potential participation. Future studies should consider using multi-lingual visual information videos to address information needs, as this may encourage participation by ethnic minority patients.

Immunogenicity and safety of heterologous Omicron BA.1 and bivalent SARS-CoV-2 recombinant spike protein booster vaccines: a phase 3, randomized, clinical trial

BACKGROUND

Mutations present in emerging SARS-CoV-2 variants permit evasion of neutralization with prototype vaccines. A novel Omicron BA.1 subvariant-specific vaccine (NVX-CoV2515) was tested alone, or as a bivalent preparation in combination with the prototype vaccine (NVX-CoV2373), to assess antibody responses to SARS-CoV-2.

METHODS

Participants aged 18 to 64 years immunized with 3 doses of prototype mRNA vaccines were randomized 1:1:1 to receive a single dose of NVX-CoV2515, NVX-CoV2373, or bivalent mixture in a phase 3 study investigating heterologous boosting with SARS-CoV-2 recombinant spike protein vaccines. Immunogenicity was measured 14 and 28 days after vaccination for the SARS-CoV-2 Omicron BA.1 sublineage and ancestral strain. Safety profiles of vaccines were assessed.

RESULTS

Of participants who received trial vaccine (N = 829), those administered NVX-CoV2515 (n = 286) demonstrated superior neutralizing antibody response to BA.1 versus NVX-CoV2373 (n = 274) at Day 14 (geometric mean titer ratio [95% CI]: 1.6 [1.33, 2.03]). Seroresponse rates [n/N; 95% CI] were 73.4% [91/124; 64.7, 80.9] for NVX-CoV2515 versus 50.9% [59/116; 41.4, 60.3] for NVX-CoV2373. All formulations were similarly well-tolerated.

CONCLUSIONS

NVX-CoV2515 elicited a superior neutralizing antibody response against the Omicron BA.1 subvariant compared with NVX-CoV2373 when administered as a fourth dose. Safety data were consistent with the established safety profile of NVX-CoV2373.

XBB.1.5 spike protein COVID-19 vaccine induces broadly neutralizing and cellular immune responses against EG.5.1 and emerging XBB variants

Monovalent SARS-CoV-2 Prototype (Wuhan-Hu-1) and bivalent (Prototype + BA.4/5) COVID-19 vaccines have demonstrated a waning of vaccine-mediated immunity highlighted by lower neutralizing antibody responses against SARS-CoV-2 Omicron XBB sub-variants. The reduction of humoral immunity due to the rapid evolution of SARS-CoV-2 has signaled the need for an update to vaccine composition. A strain change for all authorized/approved vaccines to a monovalent composition with Omicron subvariant XBB.1.5 has been supported by the WHO, EMA, and FDA. Here, we demonstrate that immunization with a monovalent recombinant spike protein COVID-19 vaccine (Novavax, Inc.) based on the subvariant XBB.1.5 induces neutralizing antibodies against XBB.1.5, XBB.1.16, XBB.2.3, EG.5.1, and XBB.1.16.6 subvariants, promotes higher pseudovirus neutralizing antibody titers than bivalent (Prototype + XBB.1.5) vaccine, induces SARS-CoV-2 spike-specific Th1-biased CD4 + T-cell responses against XBB subvariants, and robustly boosts antibody responses in mice and nonhuman primates primed with a variety of monovalent and bivalent vaccines. Together, these data support updating the Novavax vaccine to a monovalent XBB.1.5 formulation for the 2023-2024 COVID-19 vaccination campaign.

Intracorporeal or extracorporeal anastomosis after minimally invasive right colectomy: a systematic review and meta-analysis

PURPOSE

As part of the wide adoption of minimally invasive surgery, intracorporeal anastomosis is becoming increasingly common. The benefits of minimally invasive versus open right colectomy are well known although the additional benefits of an intracorporeal anastomosis, performed laparoscopically or robotically, are unclear. The aim of this study was to assess the current literature comparing intracorporeal and extracorporeal anastomosis in the setting of laparoscopic and robotic-assisted right colectomy.

METHODS

A systematic review and meta-analysis was conducted according to PRISMA and AMSTAR methods. Studies included were randomized controlled trials and prospective or retrospective cohort studies, between January 1 2010 and July 1 2021, comparing intracorporeal and extracorporeal anastomosis with laparoscopic and robotic approaches. Four groups were identified: laparoscopic extracorporeal anastomosis (L-ECA), laparoscopic intracorporeal anastomosis (L-ICA), robotic extracorporeal anastomosis (R-ECA), and robotic intracorporeal anastomosis (R-ICA). Operative time, rate of conversion to an open procedure, surgical site infection, reoperation within 30 days, postoperative complications within 30 days, and length of hospital stay were assessed.

RESULTS

Twenty-one retrospective cohort studies were included in the final analysis. R-ICA and R-ECA had comparable operative times, but a robotic approach required more time than laparoscopic (68 min longer, p < 0.00001). Conversion to open surgery was 55% less likely in the R-ICA group vs. L-ICA, and up to 94% less likely in the R-ICA group in comparison to the R-ECA group. Length of hospital stay was shorter for R-ICA by a half day vs. R-ECA, and up to 1 day less vs. L-ECA. There were no differences in postoperative complications, reoperations, or surgical site infections, regardless of approach. However, the included studies all had high risks of bias due to confounding variables and patient selection.

CONCLUSION

Robotic-assisted right colectomy with intracorporeal anastomosis was associated with shorter length of hospitalization and decreased rate of conversion to open surgery, compared to either laparoscopic or extracorporeal robotic approaches. Prospective studies are needed to better understand the true impact of robotic approach and intracorporeal anastomosis in right colectomy.

Efficacy of mRNA-1273 and Novavax ancestral or BA.1 spike booster vaccines against SARS-CoV-2 BA.5 infection in nonhuman primates

Omicron SARS-CoV-2 variants escape vaccine-induced neutralizing antibodies and cause nearly all current COVID-19 cases. Here, we compared the efficacy of three booster vaccines against Omicron BA.5 challenge in rhesus macaques: mRNA-1273, the Novavax ancestral spike protein vaccine (NVX-CoV2373), or Omicron BA.1 spike protein version (NVX-CoV2515). All three booster vaccines induced a strong BA.1 cross-reactive binding antibody and changed immunoglobulin G (Ig) dominance from IgG1 to IgG4 in the serum. All three booster vaccines also induced strong and comparable neutralizing antibody responses against multiple variants of concern, including BA.5 and BQ.1.1, along with long-lived plasma cells in the bone marrow. The ratio of BA.1 to WA-1 spike-specific antibody-secreting cells in the blood was higher in NVX-CoV2515 animals compared with NVX-CoV2373 animals, suggesting a better recall of BA.1-specific memory B cells by the BA.1 spike-specific vaccine compared with the ancestral spike-specific vaccine. Further, all three booster vaccines induced low levels of spike-specific CD4 but not CD8 T cell responses in the blood. After challenge with SARS-CoV-2 BA.5 variant, all three vaccines showed strong protection in the lungs and controlled virus replication in the nasopharynx. In addition, both Novavax vaccines blunted viral replication in nasopharynx at day 2. The protection against SARS-CoV-2 BA.5 infection in the upper respiratory airways correlated with binding, neutralizing, and ADNP activities of the serum antibody. These data have important implications for COVID-19 vaccine development, because vaccines that lower nasopharyngeal virus may help to reduce transmission.

Three Decade Single-Institution Experience of Safety and Efficacy of Radiotherapy and Adjuvant Chemotherapy for Young Adult Patients with Medulloblastoma

PURPOSE/OBJECTIVE(S)

The rarity of medulloblastoma in the adult population limits information on optimal treatment and clinical outcomes. Adjuvant chemoradiation has been correlated to improved overall survival (OS) in a recent National Cancer Database (NCDB) analysis. We performed a retrospective safety and efficacy analysis of radiation (RT) +/- adjuvant chemotherapy (aCTH) in young adult patients with medulloblastoma to better understand outcomes, prognostic factors, and possibly optimal treatment strategies.

MATERIALS/METHODS

We conducted an IRB-approved retrospective chart review on young adult (age ≥18 - 39 years old) patients with medulloblastoma treated at our institution (1992-2018) with a minimum follow-up of 6 months from completion of therapy. We gathered data on patient and disease characteristics, treatment, and clinical outcomes, including OS, progression-free survival (PFS), local control (LC), and freedom from distant metastasis (FDM). We employed Cox regression model for univariable and multivariable analyses and Kaplan-Meier (KM) test methods for survival analyses, using JMP version 15.0 software.

RESULTS

Thirty-one patients were treated with postoperative RT including craniospinal irradiation (median dose: 2340 cGy/13 fractions) followed by tumor bed/posterior fossa (median total dose: 5580 cGy/31 fractions) either alone (n = 9; 29%) or with adjuvant chemotherapy (aCTH: n = 22; 71%); mostly as per COG A9961 Regimen A: oral lomustine, intravenous cisplatin, and intravenous vincristine (n = 12). 54.6% (n = 12) were known to complete the full aCTH course. Common RT acute toxicities included G1-2 nausea and/or vomiting (N/V; n = 8) and G1-2 fatigue (n = 6). Common aCTH acute toxicities included G1-2 N/V (n = 7) and peripheral neuropathy: G1-2 (n = 6) and G3 (n = 3). Late adverse events were primarily G1-2 peripheral neuropathy and gait imbalance (22.6%), G1-2 hormonal disturbances (19.4%) and G1-2 neurocognitive impairment (16.1%). Male patients had worse OS, PFS, FDM, and LC. Age at diagnosis, tumor location (lateral vs. central), and completion of aCTH course were shown on uni- and multi-variable analysis to be significantly associated with OS; p<0.05. KM survival analysis revealed superior 10-year PFS and OS in patients who completed aCTH compared to those who received RT alone or did not complete aCTH: 72.9% vs 59.3% vs 42%, p = 0.461, and 74.1% vs 63.5% vs 40%, p = 0.033, respectively. A similar trend was noted for LC and FDM.

CONCLUSION

Our series provides a report of acute and late side effects of treatment of young adult patients with medulloblastoma. Significant OS and PFS advantage are seen of aCTH completion in this patient population. Since optimal treatment of these patients is still an unmet need, prospective studies for this rare disease entity are needed.

Strong CD4+ T-Cell Responses to Ancestral and Variant Spike Proteins Are Established by NVX-CoV2373 Severe Acute Respiratory Syndrome Coronavirus 2 Primary Vaccination

BACKGROUND

NVX-CoV2373 is an efficacious coronavirus disease 2019 (COVID-19) vaccine comprising full-length recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (rS) glycoprotein and Matrix-M adjuvant. Phase 2 of a randomized, placebo-controlled, phase 1/2 trial in healthy adults (18-84 years of age) previously reported good safety/tolerability and robust humoral immunogenicity.

METHODS

Participants were randomized to placebo or 1 or 2 doses of 5-µg or 25-µg rS with 50 µg Matrix-M adjuvant 21 days apart. CD4+ T-cell responses to SARS-CoV-2 intact S or pooled peptide stimulation (with ancestral or variant S sequences) were measured via enzyme-linked immunosorbent spot assay and intracellular cytokine staining.

RESULTS

A clearly discernable spike antigen-specific CD4+ T-cell response was induced after 1 dose, but markedly enhanced after 2 doses. Counts and fold increases in cells producing Th1 cytokines exceeded those secreting Th2 cytokines, although both phenotypes were clearly present. Interferon-γ responses to rS were detected in 93.5% of 2-dose 5-µg recipients. A polyfunctional CD4+ T-cell response was cross-reactive and of equivalent magnitude to all tested variants, including Omicron BA.1/BA.5.

CONCLUSIONS

NVX-CoV2373 elicits a moderately Th1-biased CD4+ T-cell response that is cross-reactive with ancestral and variant S proteins after 2 doses.

CLINICAL TRIALS REGISTRATION

NCT04368988.

First Double-Differential Measurement of Kinematic Imbalance in Neutrino Interactions with the MicroBooNE Detector

We report the first measurement of flux-integrated double-differential quasielasticlike neutrino-argon cross sections, which have been made using the Booster Neutrino Beam and the MicroBooNE detector at Fermi National Accelerator Laboratory. The data are presented as a function of kinematic imbalance variables which are sensitive to nuclear ground-state distributions and hadronic reinteraction processes. We find that the measured cross sections in different phase-space regions are sensitive to different nuclear effects. Therefore, they enable the impact of specific nuclear effects on the neutrino-nucleus interaction to be isolated more completely than was possible using previous single-differential cross section measurements. Our results provide precision data to help test and improve neutrino-nucleus interaction models. They further support ongoing neutrino-oscillation studies by establishing phase-space regions where precise reaction modeling has already been achieved.

3D-QSAR-based design, synthesis and biological evaluation of 2,4-disubstituted quinoline derivatives as antimalarial agents

2,4-Disubstituted quinoline derivatives were designed based on a 3D-QSAR study, synthesized and evaluated for antimalarial activity. A large dataset of 178 quinoline derivatives was used to perform a 3D-QSAR study using CoMFA and CoMSIA models. PLS analysis provided statistically validated results for CoMFA (r2ncv = 0.969, q2 = 0.677, r2cv = 0.682) and CoMSIA (r2ncv = 0.962, q2 = 0.741, r2cv = 0.683) models. Two series of a total of 40 2,4-disubstituted quinoline derivatives were designed with amide (quinoline-4-carboxamide) and secondary amine (4-aminoquinoline) linkers at the -C4 position of the quinoline ring. For the purpose of selecting better compounds for synthesis with good pEC50 values, activity prediction was carried out using CoMFA and CoMSIA models. Finally, a total of 10 2,4-disubstituted quinoline derivatives were synthesized, and screened for their antimalarial activity based on the reduction of parasitaemia. Compound #5 with amide linker and compound #19 with secondary amine linkers at the -C4 position of the quinoline ring showed maximum reductions of 64% and 57%, respectively, in the level of parasitaemia. In vivo screening assay confirmed and validated the findings of the 3D-QSAR study for the design of quinoline derivatives.

First Measurement of Quasielastic Λ Baryon Production in Muon Antineutrino Interactions in the MicroBooNE Detector

We present the first measurement of the cross section of Cabibbo-suppressed Λ baryon production, using data collected with the MicroBooNE detector when exposed to the neutrinos from the main injector beam at the Fermi National Accelerator Laboratory. The data analyzed correspond to 2.2×10^{20} protons on target running in neutrino mode, and 4.9×10^{20} protons on target running in anti-neutrino mode. An automated selection is combined with hand scanning, with the former identifying five candidate Λ production events when the signal was unblinded, consistent with the GENIE prediction of 5.3±1.1 events. Several scanners were employed, selecting between three and five events, compared with a prediction from a blinded Monte Carlo simulation study of 3.7±1.0 events. Restricting the phase space to only include Λ baryons that decay above MicroBooNE's detection thresholds, we obtain a flux averaged cross section of 2.0_{-1.7}^{+2.2}×10^{-40}  cm^{2}/Ar, where statistical and systematic uncertainties are combined.

Immunogenicity and safety of a fourth homologous dose of NVX-CoV2373

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has significantly reduced the efficacy of some approved vaccines. A fourth dose of NVX-CoV2373 (5 µg SARS-CoV-2 recombinant spike [rS] protein + 50 µg Matrix-M™ adjuvant; Novavax, Gaithersburg, MD) was evaluated to determine induction of cross-reactive antibodies to variants of concern. A phase II randomized study (NCT04368988) recruited participants in Australia and the United States to assess a primary series of NVX-CoV2373 followed by two booster doses (third and fourth doses at 6-month intervals) in adults 18-84 years of age. The primary series was administered when the SARS-CoV-2 ancestral strain was prevalent and the third and fourth doses while the Alpha and Delta variants were prevalent in AUS and US. Local/systemic reactogenicity was assessed the day of vaccination and for 6 days thereafter. Unsolicited adverse events (AEs) were reported. Immunogenicity was measured before, and 14 days after, fourth dose administration, using anti-spike serum immunoglobulin G (IgG) and neutralization assays against ancestral SARS-CoV-2 strain and Omicron sublineages. Among 1283 enrolled participants, 258 were randomized to receive the two-dose primary series, of whom 104 received a third dose, and 45 received a fourth dose of NVX-CoV2373. The incidence of local/systemic reactogenicity events increased after the first three doses of NVX-CoV2373 and leveled off after dose 4. Unsolicited AEs were reported in 9 % of participants after dose 4 (none of which were severe or serious). Anti-rS IgG levels and neutralization antibody titers increased following booster doses to a level approximately four-fold higher than that observed after the primary series, with a progressively narrowed gap in response between the ancestral strain and Omicron BA.5. A fourth dose of NVX-CoV2373 enhanced immunogenicity for ancestral and variant SARS-CoV-2 strains without increasing reactogenicity, indicating that updates to the vaccine composition may not be currently warranted.

Diet Induced Obesity and Diabetes Enhance Mortality and Reduces Vaccine Efficacy for SARS-CoV-2

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of Coronavirus disease 2019 (COVID-19), emerged in Wuhan, China, in December 2019. As of October 2022, there have been over 625 million confirmed cases of COVID-19, including over 6.5 million deaths. Epidemiological studies have indicated that comorbidities of obesity and diabetes mellitus are associated with increased morbidity and mortality following SARS-CoV-2 infection. We determined how the comorbidities of obesity and diabetes affect morbidity and mortality following SARS-CoV-2 infection in unvaccinated and adjuvanted spike nanoparticle (NVX-CoV2373) vaccinated mice. We find that obese/diabetic mice infected with SARS-CoV-2 have increased morbidity and mortality compared to age matched normal mice. Mice fed a high-fat diet (HFD) then vaccinated with NVX-CoV2373 produce equivalent neutralizing antibody titers to those fed a normal diet (ND). However, the HFD mice have reduced viral clearance early in infection. Analysis of the inflammatory immune response in HFD mice demonstrates a recruitment of neutrophils that was correlated with increased mortality and reduced clearance of the virus. Depletion of neutrophils in diabetic/obese vaccinated mice reduced disease severity and protected mice from lethality. This model recapitulates the increased disease severity associated with obesity and diabetes in humans with COVID-19 and is an important comorbidity to study with increasing obesity and diabetes across the world.

Safety, Immunogenicity, and Efficacy of the NVX-CoV2373 COVID-19 Vaccine in Adolescents: A Randomized Clinical Trial

Importance

Greater than 20% of cases and 0.4% of deaths from COVID-19 occur in children. Following demonstration of the safety and efficacy of the adjuvanted, recombinant spike protein vaccine NVX-CoV2373 in adults, the PREVENT-19 trial immediately expanded to adolescents.

Objective

To evaluate the safety, immunogenicity, and efficacy of NVX-CoV2373 in adolescents.

Design, Setting, and Participants

The NVX-CoV2373 vaccine was evaluated in adolescents aged 12 to 17 years in an expansion of PREVENT-19, a phase 3, randomized, observer-blinded, placebo-controlled multicenter clinical trial in the US. Participants were enrolled from April 26 to June 5, 2021, and the study is ongoing. A blinded crossover was implemented after 2 months of safety follow-up to offer active vaccine to all participants. Key exclusion criteria included known previous laboratory-confirmed SARS-CoV-2 infection or known immunosuppression. Of 2304 participants assessed for eligibility, 57 were excluded and 2247 were randomized.

Interventions

Participants were randomized 2:1 to 2 intramuscular injections of NVX-CoV2373 or placebo, 21 days apart.

Main Outcomes and Measures

Serologic noninferiority of neutralizing antibody responses compared with those in young adults (aged 18-25 years) in PREVENT-19, protective efficacy against laboratory-confirmed COVID-19, and assessment of reactogenicity and safety.

Results

Among 2232 participants (1487 NVX-CoV2373 and 745 placebo recipients), the mean (SD) age was 13.8 (1.4) years, 1172 (52.5%) were male, 1660 (74.4%) were White individuals, and 359 (16.1%) had had a previous SARS-CoV-2 infection at baseline. After vaccination, the ratio of neutralizing antibody geometric mean titers in adolescents compared with those in young adults was 1.5 (95% CI, 1.3-1.7). Twenty mild COVID-19 cases occurred after a median of 64 (IQR, 57-69) days of follow-up, including 6 among NVX-CoV2373 recipients (incidence, 2.90 [95% CI, 1.31-6.46] cases per 100 person-years) and 14 among placebo recipients (incidence, 14.20 [95% CI, 8.42-23.93] cases per 100 person-years), yielding a vaccine efficacy of 79.5% (95% CI, 46.8%-92.1%). Vaccine efficacy for the Delta variant (the only viral variant identified by sequencing [n = 11]) was 82.0% (95% CI, 32.4%-95.2%). Reactogenicity was largely mild to moderate and transient, with a trend toward greater frequency after the second dose of NVX-CoV2373. Serious adverse events were rare and balanced between treatments. No adverse events led to study discontinuation.

Conclusions and Relevance

The findings of this randomized clinical trial indicate that NVX-CoV2373 is safe, immunogenic, and efficacious in preventing COVID-19, including the predominant Delta variant, in adolescents.

Trial Registration

ClinicalTrials.gov Identifier: NCT04611802.

Elamipretide mitigates ischemia-reperfusion injury in a swine model of hemorrhagic shock

ischemia-reperfusion injury (IRI) after hemorrhage is potentiated by aortic occlusion or resuscitative endovascular balloon occlusion of the aorta (REBOA). Given the central role of mitochondrial injury in shock, we hypothesized that Elamipretide, a peptide that protects mitochondria, would mitigate IRI after hemorrhagic shock and REBOA. Twelve pigs were subjected to hemorrhagic shock and 45 min of REBOA. After 25 min of REBOA, animals received either saline or Elamipretide. Animals were transfused with autologous blood during balloon deflation, and pigs were resuscitated with isotonic crystalloids and norepinephrine for 4.25 h. Elamipretide-treated animals required less crystalloids than the controls (62.5 [50-90] and 25 [5-30] mL/kg, respectively), but similar amounts of norepinephrine (24.7 [8.6-39.3] and 9.7 [2.1-12.5] mcg/kg, respectively). Treatment animals had a significant reduction in serum creatinine (control: 2.7 [2.6-2.8]; Elamipretide: 2.4 [2.4-2.5] mg/dL; p = 0.04), troponin (control: 3.20 [2.14-5.47] ng/mL, Elamipretide: 0.22 [0.1-1.91] ng/mL; p = 0.03), and interleukin-6 concentrations at the end of the study. There were no differences in final plasma lactate concentration. Elamipretide reduced fluid requirements and protected the kidney and heart after profound IRI. Further understanding the subcellular consequences of REBOA and mitochondrial rescue will open new therapeutic avenues for patients suffering from IRI after hemorrhage.

A 15-year experience: intraoperative parathyroid hormone assay for the management of primary hyperparathyroidism in a UK endocrine surgical unit

PURPOSE

This study aims to evaluate the outcomes of first-time parathyroidectomy for primary hyperparathyroidism using intraoperative PTH (IOPTH) assay in the light of the UK National Institute for Health and Care Excellence (NICE) guidelines for the management of primary hyperparathyroidism.

METHOD

This is a retrospective cohort analysis of a prospectively maintained database of endocrine surgery in a tertiary centre. Preoperative radiological localisation (concordance and accuracy), intraoperative PTH parameters and adjusted serum calcium at minimum 6-month follow-up were analysed. The accuracy of IOPTH to predict post-operative normocalcaemia and the number needed to treat (NNT) within the cohort when IOPTH was utilised were determined. Differences between groups were evaluated with Chi-squared and Fisher's exact test.

RESULTS

Between January 2004 and September 2018, 849 patients (75.4% women), median age 64 years (IQR 54-72), were analysed. The median preoperative adjusted serum calcium was 2.80mmol/l (IQR 2.78-2.90), and the median preoperative PTH was 14.20pmol/l (IQR 10.70-20.25). The overall first-time cure (normocalcaemia) rate was 96.4%. The sensitivity, specificity, positive predictive value and negative predictive values of IOPTH were 96.8%, 83.2%, 97.6% and 78.8%, respectively, with an accuracy of 95.1%. For patients with concordant scans (48.3%), a targeted approach without IOPTH would have achieved a cure rate of 94.1% compared with 98.0% using IOPTH (p<0.01) CONCLUSION: The use of IOPTH assay significantly improved the rate of normocalcaemia at 6 months. The low NNT to benefit from IOPTH, particularly those patients with a single positive scan, and the inevitable reduction in the potential costs incurred from failure and reoperation justify its utilisation.

Extrapleural fat: description, incidence, and relation with body mass index

BACKGROUND AND AIMS

Pleural appendages (PA) are portions of extrapleural fat that hang from the chest wall. They have been described on videothoracoscopy, however their appearance, frequency and possible relationship with the amount of patient's fat remain unknown. Our aim is to describe their appearances and prevalence on CT, and determinate whether their size and number is higher in obese patients.

PATIENTS AND METHODS

Axial images of 226 patients with pneumothorax on CT chest were retrospectively reviewed. Exclusion criteria included known pleural disease, previous thoracic surgery and small pneumothorax. Patients were divided in obese (BMI>30) and non-obese (BMI<30) groups. Presence, position, size and number of PA were recorded. Chi square and Fisher's exact test were used to evaluate differences between the two groups, considering p<0.05 as significant.

RESULTS

Valid CT studies were available for 101 patients. Extrapleural fat was identified in 50 (49.5%) patients. Most were solitary (n=31). Most were located in the cardiophrenic angle (n=27), and most measured <5cm (n=39). There was no significant difference between obese and non-obese patients regarding the presence or absence of PA (p=0.315), number (p=0.458) and size (p=0.458).

CONCLUSIONS

Pleural appendages were seen in 49.5% patients with pneumothorax on CT. There was no significant difference between obese and non-obese patients regarding presence, number and size of pleural appendages.

Immunogenicity and protection of a variant nanoparticle vaccine that confers broad neutralization against SARS-CoV-2 variants

SARS-CoV-2 variants have emerged with elevated transmission and a higher risk of infection for vaccinated individuals. We demonstrate that a recombinant prefusion-stabilized spike (rS) protein vaccine based on Beta/B.1.351 (rS-Beta) produces a robust anamnestic response in baboons against SARS-CoV-2 variants when given as a booster one year after immunization with NVX-CoV2373. Additionally, rS-Beta is highly immunogenic in mice and produces neutralizing antibodies against WA1/2020, Beta/B.1.351, and Omicron/BA.1. Mice vaccinated with two doses of Novavax prototype NVX-CoV2373 (rS-WU1) or rS-Beta alone, in combination, or heterologous prime-boost, are protected from challenge. Virus titer is undetectable in lungs in all vaccinated mice, and Th1-skewed cellular responses are observed. We tested sera from a panel of variant spike protein vaccines and find broad neutralization and inhibition of spike:ACE2 binding from the rS-Beta and rS-Delta vaccines against a variety of variants including Omicron. This study demonstrates that rS-Beta vaccine alone or in combination with rS-WU1 induces antibody-and cell-mediated responses that are protective against challenge with SARS-CoV-2 variants and offers broader neutralizing capacity than a rS-WU1 prime/boost regimen alone. Together, these nonhuman primate and murine data suggest a Beta variant booster dose could elicit a broad immune response to fight new and future SARS-CoV-2 variants.

How do I save cell therapy product's storage space?

BACKGROUND

Availability of liquid nitrogen (LN2) freezer storage space is a major challenge for many transplant programs as they continue to grow and accumulate products. The recent trend of allogeneic grafts cryopreservation that started during the COVID-19 pandemic, made the situation even worse requiring an increase in storage capacity. Multi-compartment cryopreservation bags can help save storage space but can be tricky to use. Here, we describe the validation of muti-compartment cryopreservation bags for the purpose of donor lymphocyte infusion (DLI) aliquots.

METHODS

We validated the use of five compartment cryobags for cryopreservation of cell therapy products. Four products were cryopreserved using these bags and each compartment was tested post-thaw for product volume distribution, total cell count recovery, and viability. Additionally, the integrity of both bag compartments and labels was assessed as well.

RESULTS

All tested specimens met post-thaw viability and TNC recovery acceptability criteria. Fill volume was optimized at 24-25 mL for acceptable volume distribution between aliquots. With proper heat sealing between compartments, all aliquots retain their integrity and cryopreservation labels were adherent and legible.

CONCLUSIONS

Muti-compartment bags can be used successfully for cryopreservation of cell therapy products and increase storage capacity.

Final Study Report of Andexanet Alfa for Major Bleeding With Factor Xa Inhibitors

BACKGROUND

Andexanet alfa is a modified recombinant inactive factor Xa (FXa) designed to reverse FXa inhibitors. ANNEXA-4 (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) was a multicenter, prospective, phase-3b/4, single-group cohort study that evaluated andexanet alfa in patients with acute major bleeding. The results of the final analyses are presented.

METHODS

Patients with acute major bleeding within 18 hours of FXa inhibitor administration were enrolled. Co-primary end points were anti-FXa activity change from baseline during andexanet alfa treatment and excellent or good hemostatic efficacy, defined by a scale used in previous reversal studies, at 12 hours. The efficacy population included patients with baseline anti-FXa activity levels above predefined thresholds (≥75 ng/mL for apixaban and rivaroxaban, ≥40 ng/mL for edoxaban, and ≥0.25 IU/mL for enoxaparin; reported in the same units used for calibrators) who were adjudicated as meeting major bleeding criteria (modified International Society of Thrombosis and Haemostasis definition). The safety population included all patients. Major bleeding criteria, hemostatic efficacy, thrombotic events (stratified by occurring before or after restart of either prophylactic [ie, a lower dose, for prevention rather than treatment] or full-dose oral anticoagulation), and deaths were assessed by an independent adjudication committee. Median endogenous thrombin potential at baseline and across the follow-up period was a secondary outcome.

RESULTS

There were 479 patients enrolled (mean age, 78 years; 54% male, 86% White; 81% anticoagulated for atrial fibrillation at a median time of 11.4 hours since last dose, with 245 (51%) on apixaban, 176 (37%) on rivaroxaban, 36 (8%) on edoxaban, and 22 (5%) on enoxaparin. Bleeding was predominantly intracranial (n=331 [69%]) or gastrointestinal (n=109 [23%]). In evaluable apixaban patients (n=172), median anti-FXa activity decreased from 146.9 ng/mL to 10.0 ng/mL (reduction, 93% [95% CI, 94-93]); in rivaroxaban patients (n=132), it decreased from 214.6 ng/mL to 10.8 ng/mL (94% [95% CI, 95-93]); in edoxaban patients (n=28), it decreased from 121.1 ng/mL to 24.4 ng/mL (71% [95% CI, 82-65); and in enoxaparin patients (n=17), it decreased from 0.48 IU/mL to 0.11 IU/mL (75% [95% CI, 79-67]). Excellent or good hemostasis occurred in 274 of 342 evaluable patients (80% [95% CI, 75-84]). In the safety population, thrombotic events occurred in 50 patients (10%); in 16 patients, this occurred during treatment with prophylactic anticoagulation that began after the bleeding event. No thrombotic episodes occurred after oral anticoagulation restart. Specific to certain populations, reduction of anti-FXa activity from baseline to nadir significantly predicted hemostatic efficacy in patients with intracranial hemorrhage (area under the receiver operating characteristic curve, 0.62 [95% CI, 0.54-0.70]) and correlated with lower mortality in patients <75 years of age (adjusted P=0.022; unadjusted P=0.003). Median endogenous thrombin potential was within the normal range by the end of andexanet alfa bolus through 24 hours for all FXa inhibitors.

CONCLUSIONS

In patients with major bleeding associated with the use of FXa inhibitors, treatment with andexanet alfa reduced anti-FXa activity and was associated with good or excellent hemostatic efficacy in 80% of patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02329327.

Prediction of long-term dependence on vitamin D analogues following total thyroidectomy for Graves' disease

INTRODUCTION

This study aimed to identify patients at risk of long-term hypocalcaemia following total thyroidectomy for Graves' disease, and to determine the thresholds of postoperative day 1 serum calcium and parathyroid hormone (PTH) at which long-term activated vitamin D treatment can be safely excluded.

METHODS

This study was a retrospective analysis of 115 consecutive patients undergoing total thyroidectomy for Graves' disease at a university referral centre between 2010 and 2018. Outcome measures were the day 1 postoperative adjusted calcium and PTH results, and vitamin D analogue need at 6 months postoperatively. Logistic receiver operating curves were used to identify optimal cut-off values for adjusted serum calcium and serum PTH, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated.

RESULTS

Temporary hypocalcaemia was observed in 20.9% of patients (mean day 1 serum adjusted calcium 2.2±0.14mmol/l and PTH 4.15±2.42pmol/l). Long-term (>6 months) activated vitamin D analogue therapy was required in five patients (4.3%), four of whom had normal serum PTH and one with undetectable PTH at 6 weeks post surgery. No patient with a day 1 postoperative calcium >2.05mmol/l and detectable PTH required vitamin D supplementation at 6 months post surgery (100% sensitivity, PPV 50%, NPV 100%).

CONCLUSIONS

The biochemical postoperative day 1 thresholds identified in this paper have a 100% NPV in the identification of patients who are likely to require either no or only temporary activated vitamin D supplementation. We were able to identify all patients requiring activated vitamin D supplementation 6 months postoperatively from the day 1 postoperative serum calcium and PTH values, while excluding those that may only need temporary calcium supplementation. These threshold levels could be used for targeted follow-up and management of this subset of patients most at risk of long-term hypocalcaemia.

First Constraints on Light Sterile Neutrino Oscillations from Combined Appearance and Disappearance Searches with the MicroBooNE Detector

We present a search for eV-scale sterile neutrino oscillations in the MicroBooNE liquid argon detector, simultaneously considering all possible appearance and disappearance effects within the 3+1 active-to-sterile neutrino oscillation framework. We analyze the neutrino candidate events for the recent measurements of charged-current ν_{e} and ν_{μ} interactions in the MicroBooNE detector, using data corresponding to an exposure of 6.37×10^{20} protons on target from the Fermilab booster neutrino beam. We observe no evidence of light sterile neutrino oscillations and derive exclusion contours at the 95% confidence level in the plane of the mass-squared splitting Δm_{41}^{2} and the sterile neutrino mixing angles θ_{μe} and θ_{ee}, excluding part of the parameter space allowed by experimental anomalies. Cancellation of ν_{e} appearance and ν_{e} disappearance effects due to the full 3+1 treatment of the analysis leads to a degeneracy when determining the oscillation parameters, which is discussed in this Letter and will be addressed by future analyses.

LB746. Safety and Immunogenicity of a Booster Dose of Novavax COVID-19 Vaccine, Adjuvanted (NVX-CoV2373) in Adults from the PREVENT-19 Trial in the United States

Background

Novavax COVID-19 Vaccine, Adjuvanted (5 µg recombinant spike protein/50 µg Matrix-MTM adjuvant; NVX-CoV2373) has received regulatory authorizations for use in adults ≥ 18 years globally.

Methods

Participants from PREVENT-19 (NCT04611802), a phase 3, randomized, observer-blinded, placebo-controlled trial that evaluated the efficacy, safety, and immunogenicity of a primary series of 2 doses of NVX-CoV2373 given 21 days apart, in adults ≥ 18 years in the United States and Mexico, were eligible to receive a booster dose at least 6 months after the initial vaccination series. Short-term safety and immunogenicity of the booster dose was assessed in an ad hoc analysis of 298 participants.

Results

There was an incremental increase compared to the initial vaccination series in local and systemic reactogenicity, which was transient and mostly mild-to-moderate in intensity. Most unsolicited adverse events were also mild-to-moderate in severity; there were no deaths or treatment-related SAEs and 2/298 booster recipients in this analysis reported unrelated SAEs. Neutralizing, anti-S IgG, and hACE2 receptor binding inhibiting antibodies against the ancestral (Wuhan) strain 28 days after booster were higher than those 14 days after primary vaccination (Table). Overall, humoral responses were high regardless of interval between priming and booster vaccination, but a longer interval yielded stronger responses. Higher immune responses against the Omicron BA.1, BA.2, and BA.5 variants were also observed after the booster dose than after the primary series in a subset of 14-18 participants tested. Overall, humoral responses were high and broad regardless of age after any vaccination, but higher responses were observed in adults &lt; 65 years after initial and booster vaccinations. A booster dose induced more robust antibody responses compared with the primary series in adults ≥ 65 years.

Conclusion

A single booster dose of NVX-CoV2373 demonstrated a satisfactory safety profile, and high levels of neutralizing, anti-S IgG, and hACE2 inhibition antibody responses against the SARS-CoV-2 prototype Wuhan as well as against the Omicron variant including recently emerged sub-variants.

Disclosures

Germán Áñez, MD, Novavax Inc.: employer|Novavax Inc.: Stocks/Bonds Lisa M. Dunkle, MD, Novavax, Inc: Employee|Novavax, Inc: Stocks/Bonds Nita Patel, MS, CRP, Novavax, Inc.: employer|Novavax, Inc.: Stocks/Bonds Joyce S. Plested, PhD, Novavax Inc.: employer|Novavax Inc.: Stocks/Bonds|Novavax Inc.: Stocks/Bonds Alice McGarry, MPH, Novavax: Employee|Novavax: Stocks/Bonds Wayne Woo, MS, Novavax: Employee|Novavax: Stocks/Bonds Rongman Cai, PhD, Novavax Inc.: employer|Novavax Inc.: Stocks/Bonds Iksung Cho, MS, Novavax, Inc.: employer|Novavax, Inc.: Stocks/Bonds.