Autoimmune encephalitis in Israeli children - A retrospective nationwide study.

Immune-mediated or autoimmune encephalitis (AE) is a relatively new, rare and elusive form of encephalitis in children. We retrospectively collected seropositive children (0-18 years old) with well characterized antibodies through 3 reference laboratories in Israel. Clinical symptoms, MRI and EEG findings and treatment courses were described. A total of 16 patients were included in the study, with 10 females. Anti NMDA encephalitis was most common followed by anti HU and anti mGLuR1. Psychiatric symptoms, abnormal movements, seizures and behavioral changes were the most common presentation. Pathological MRI and EEG findings were described in 37% and 56% of children, respectively. Treatment with corticosteroids, Intravenous immunoglobulins (IVIG) was first line in most children. Following inadequate response children were treated with plasmapheresis and/or rituximab. Two patients relapsed following both first and second line protocols. In terms of long term prognosis, 9 children (56%) had one or more residual behavioral, psychiatric or neurologic findings. Three children required hospitalization for rehabilitation. AE remains a rare diagnosis with variable presenting symptoms, requiring a high index of suspicion. Consensus recommended treatment is generally effective in the pediatric population. Female gender was associated with a higher chance of severe disease. Larger cohorts would be needed to identify prognostic factors in the pediatric population.

Toward the quantification of α-synuclein aggregates with digital seed amplification assays.

The quantification and characterization of aggregated α-synuclein in clinical samples offer immense potential toward diagnosing, treating, and better understanding neurodegenerative synucleinopathies. Here, we developed digital seed amplification assays to detect single α-synuclein aggregates by partitioning the reaction into microcompartments. Using pre-formed α-synuclein fibrils as reaction seeds, we measured aggregate concentrations as low as 4 pg/mL. To improve our sensitivity, we captured aggregates on antibody-coated magnetic beads before running the amplification reaction. By first characterizing the pre-formed fibrils with transmission electron microscopy and size exclusion chromatography, we determined the specific aggregates targeted by each assay platform. Using brain tissue and cerebrospinal fluid samples collected from patients with Parkinson's Disease and multiple system atrophy, we demonstrated that the assay can detect endogenous pathological α-synuclein aggregates. Furthermore, as another application for these assays, we studied the inhibition of α-synuclein aggregation in the presence of small-molecule inhibitors and used a custom image analysis pipeline to quantify changes in aggregate growth and filament morphology.

Validation of the 2023 international diagnostic criteria for MOGAD in a pediatric cohort.

OBJECTIVE: To validate the recently published diagnostic criteria for Myelin Oligodendrocyte Glycoprotein-antibody associated disease (MOGAD) in real-world cohort of children with acquired demyelinating syndromes. METHODS: Patients <18yrs presenting with demyelinating disease to Pediatric neuroimmunology clinics at two Israeli tertiary centers who had MOG antibodies (MOG-Abs) tested between 01/07/2017 and 15/08/2023 were included. Diagnostic criteria for MOGAD were applied and sensitivity and specificities were calculated. RESULTS: MOG-Abs were detected in 28/63 (44 %). Median age at onset for all patients was 11.4 yrs (range 1.1-17.6 yrs) and 41 (65 %) were female. Of the patients testing negative, ADEM was the most common diagnosis (n = 11) followed by MS (n = 8). No patients without MOG-Abs were diagnosed with MOGAD. All patients with a clinical diagnosis of MOGAD had positive MOG-Abs and fulfilled the 2023 international diagnostic criteria for MOGAD. Sensitivity, specificity, positive predictive value, and negative predictive value were 100 %. We found no difference between younger (<10yrs old) and older (>10 yrs old) children in the number of supportive criteria fulfilled at onset (median 2 vs. 2.5, p = 0.4) The number of supporting features was higher in patients with relapsing (n = 5) vs. monophasic (n = 23) disease course at onset (median 3 vs. 2, p = 0.03) and at final follow-up (median 5 vs. 2, p = 0.004). CONCLUSION: Recent MOGAD diagnostic criteria had excellent performance in this pediatric cohort but did not add to the diagnostic accuracy of the antibody test alone.

Real-Life Experience With Purified Cannabidiol Treatment for Refractory Epilepsy: A Multicenter Retrospective Study.

BACKGROUND: Drug-resistant epilepsy (DRE) affects the development and quality of life of children and young adults. We analyzed the effectiveness and safety of purified CBD in this population. METHODS: A retrospective analysis of medical records of 139 children and young adults (54.7% female, median age 12.0 years) with DRE treated with purified CBD from 2018 to 2022 at five medical centers in Israel. RESULTS: The most common diagnosis was Lennox-Gastaut syndrome (37.4%) followed by Dravet syndrome (16.5%) and tuberous sclerosis complex (16.5%). Median purified CBD dose was 12.5 mg/kg (range 2.5 to 20.0), and median treatment duration was 9.0 months (range 0.5 to 48.0). Most patients (92.2%) had a reduced seizure frequency following treatment initiation; 41.1% had >50% reduction. Fifty-three patients (38.1%) had positive effects: improved alertness (31.7%), improved speech (10.1%), and achievement of new developmental milestones (2.2%). A multivariate linear model assessing predictive factors for seizure reduction demonstrated that patients previously treated with CBD oils, especially those with >50% seizure reduction on prior treatment, were also more likely to have a reduced seizure frequency while they were treated with purified CBD (P = 0.01, P < 0.0001). Development, diagnosis, age, purified CBD dose (0 to 10 mg/kg/day vs 10 to 20 mg/kg/day), and concomitant treatment with clobazam, valproic acid, or everolimus did not affect seizure reduction by purified CBD. The most common adverse events were irritability (20.9%) and drowsiness (12.9%). CONCLUSION: Purified CBD is well-tolerated and effective in reducing seizure frequency in children and young adults with DRE.

Novel homozygous variants in PRORP expand the genotypic spectrum of combined oxidative phosphorylation deficiency 54.

Biallelic hypomorphic variants in PRORP have been recently described as causing the autosomal recessive disorder combined oxidative phosphorylation deficiency type 54 (COXPD54). COXPD54 encompasses a phenotypic spectrum of sensorineural hearing loss and ovarian insufficiency (Perrault syndrome) to leukodystrophy. Here, we report three additional families with homozygous missense PRORP variants with pleiotropic phenotypes. Each missense variant altered a highly conserved residue within the metallonuclease domain. In vitro mitochondrial tRNA processing assays with recombinant TRMT10C, SDR5C1 and PRORP indicated two COXPD54-associated PRORP variants, c.1159A>G (p.Thr387Ala) and c.1241C>T (p.Ala414Val), decreased pre-tRNAIle cleavage, consistent with both variants impacting tRNA processing. No significant decrease in tRNA processing was observed with PRORP c.1093T>C (p.Tyr365His), which was identified in an individual with leukodystrophy. These data provide independent evidence that PRORP variants are associated with COXPD54 and that the assessment of 5' leader mitochondrial tRNA processing is a valuable assay for the functional analysis and clinical interpretation of novel PRORP variants.

Improved isolation of extracellular vesicles by removal of both free proteins and lipoproteins.

Extracellular vesicles (EVs) are released by all cells into biofluids such as plasma. The separation of EVs from highly abundant free proteins and similarly sized lipoproteins remains technically challenging. We developed a digital ELISA assay based on Single Molecule Array (Simoa) technology for ApoB-100, the protein component of several lipoproteins. Combining this ApoB-100 assay with previously developed Simoa assays for albumin and three tetraspanin proteins found on EVs (Ter-Ovanesyan, Norman et al., 2021), we were able to measure the separation of EVs from both lipoproteins and free proteins. We used these five assays to compare EV separation from lipoproteins using size exclusion chromatography with resins containing different pore sizes. We also developed improved methods for EV isolation based on combining several types of chromatography resins in the same column. We present a simple approach to quantitatively measure the main impurities of EV isolation in plasma and apply this approach to develop novel methods for enriching EVs from human plasma. These methods will enable applications where high-purity EVs are required to both understand EV biology and profile EVs for biomarker discovery.

A recurrent de novo variant in NUSAP1 escapes nonsense-mediated decay and leads to microcephaly, epilepsy, and developmental delay.

NUSAP1 encodes a cell cycle-dependent protein with key roles in mitotic progression, spindle formation, and microtubule stability. Both over- and under-expression of NUSAP1 lead to dysregulation of mitosis and impaired cell proliferation. Through exome sequencing and Matchmaker Exchange, we identified two unrelated individuals with the same recurrent, de novo heterozygous variant (NM_016359.5 c.1209C > A; p.(Tyr403Ter)) in NUSAP1. Both individuals had microcephaly, severe developmental delay, brain abnormalities, and seizures. The gene is predicted to be tolerant of heterozygous loss-of-function mutations, and we show that the mutant transcript escapes nonsense mediated decay, suggesting that the mechanism is likely dominant-negative or toxic gain of function. Single-cell RNA-sequencing of an affected individual's post-mortem brain tissue indicated that the NUSAP1 mutant brain contains all main cell lineages, and that the microcephaly could not be attributed to loss of a specific cell type. We hypothesize that pathogenic variants in NUSAP1 lead to microcephaly possibly by an underlying defect in neural progenitor cells.

Disulfide Bonds Are Not Necessary for Intrinsic TNSALP Activity.

Recent developments in single-molecule enzymology (SME) have allowed for the observation of subpopulations present in enzyme ensembles. Tissue-nonspecific alkaline phosphatase (TNSALP), a homodimeric monophosphate esterase central to bone metabolism, has become a model enzyme for SME studies. TNSALP contains two internal disulfide bonds that are critical for its effective dimerization; mutations in its disulfide bonding framework have been reported in patients with hypophosphatasia, a rare disease characterized by impaired bone and tooth mineralization. In this paper, we present the kinetics of these mutants and show that these disulfide bonds are not crucial for TNSALP enzymatic function. This surprising result reveals that the enzyme's active conformation does not rely on its disulfide bonds. We posit that the signs and symptoms seen in hypophosphatasia are likely not primarily due to impaired enzyme function, but rather decreased enzyme expression and trafficking.

Delineating the phenotype and genetic basis of AMPD2-related pontocerebellar hypoplasia.

Pontocerebellar hypoplasia is a group of disorders with a wide range of presentations. We describe here the genetic and phenotypic features of PCH type 9 due to mutations in AMPD2. All patients have severe intellectual disability, and the vast majority manifest abnormal tone, cortical blindness, and microcephaly. Almost all have agenesis of the corpus callosum and severe cerebellar hypoplasia. The course is not progressive, however, few die in the first decade of life. Mutations are spread throughout the gene, and no hot spot can be identified. One of the mutations we report here is the most distal truncating variant known in this gene and is predicted to result in a truncated protein. The phenotype is severe in all cases; thus, no clear genotype-phenotype correlation can be established.

The yield of ophthalmoscopy as a screening tool for intracranial pathology in pediatric headache.

Headache is a common complaint in children who present at the pediatric emergency department (PED). Serious conditions such as intracranial tumors and idiopathic intracranial hypertension (IIH) should be rapidly ruled out. Ophthalmoscopy for the presence of papilledema has long been considered critical to the assessment of headaches in children; however, the yield of this procedure is poorly validated. This retrospective study implemented a computerized search of the medical records of a single tertiary center to identify all children aged 2-18 years who presented at the PED complaining of headache between 2007 and 2017. The clinical, demographic, radiographic, and laboratory data were analyzed. Of the 948 children aged 2-18 years who presented at the PED complaining of headache, 536 had an ophthalmoscopy examination carried out by an ophthalmologist. Forty-one had papilledema, of whom 7 had an intracranial tumor, 15 had IIH, and 9 had optic nerve head drusen. Of the 495 children without papilledema, 3 had intracranial tumor, and 11 had IIH. The sensitivity and specificity of papilledema for the diagnosis of intracranial tumor were 70% and 93.5%, respectively, with an NPV and PPV of 99.4% and 17.1%, respectively. The sensitivity and specificity of papilledema for the diagnosis of intracranial pathology in general were 61.1% and 96.2%, respectively, with an NPV and PPV of 97.2% and 53.7%, respectively.  Conclusion: Assessment by ophthalmoscopy for papilledema in children presenting to the PED with headache had high sensitivity and high specificity, thus reinforcing the importance of ophthalmoscopy as a screening tool in these children. What is Known: • Headache is a common complaint in children. Serious intracranial pathologies need to be rapidly excluded. • Ophthalmoscopy for the presence of papilledema is commonly used as a screening tool for intracranial pathology, but this procedure is poorly validated. What is New: • Ophthalmoscopy for the assessment of papilledema in children who present with headache to the pediatric emergency department is shown to exhibit sensitivity and specificity for the diagnosis of intracranial pathology.

Improving pediatric idiopathic intracranial hypertension care: a retrospective cohort study.

To describe the clinical course and prognosis of pediatric idiopathic intracranial hypertension (IIH) and examine the preferred management setting. IIH is characterized by increased intracranial pressure and is often associated with headaches and visual complaints. IIH is a preventable cause of vision loss in children. Hence, a rapid diagnosis followed by prompt treatment and follow-up is essential. However, standardization of the management of IIH in the pediatric population is not well established. Computerized medical charts of all 82 pediatric (< 18 years) patients diagnosed with IIH between 2007 and 2018 in the metropolitan area of Jerusalem were reviewed. Comparison was made between children followed in a multidisciplinary clinic in tertiary centers and those followed elsewhere. Detailed demographic and clinical data, as well as data regarding the follow-up setting and clinical course of the disease, were collected and analyzed. Recurrent IIH-related hospital returns were selected as a measurable marker for the uncontrolled disease. Recurrent IIH-related hospital return rate was significantly lower and occurred later among children followed by multidisciplinary teams compared to individual experts. Follow-up in multidisciplinary clinics improve the quality of life, and financial burden and may prevent permanent visual impairment in children with IIH.

What is the optimal duration of home-video-EEG monitoring for patients with <1 seizure per day? A simulation study.

Ambulatory "at home" video-EEG monitoring (HVEM) may offer a more cost-effective and accessible option as compared to traditional inpatient admissions to epilepsy monitoring units. However, home monitoring may not allow for safe tapering of anti-seizure medications (ASM). As a result, longer periods of monitoring may be necessary to capture a sufficient number of the patients' stereotypic seizures. We aimed to quantitatively estimate the necessary length of HVEM corresponding to various diagnostic scenarios in clinical practice. Using available seizure frequency statistics, we estimated the HVEM duration required to capture one, three, or five seizures on different days, by simulating 100,000 annual time-courses of seizure occurrence in adults and children with more than one and <30 seizures per month (89% of adults and 85% of children). We found that the durations of HVEM needed to record 1, 3, or 5 seizures in 80% of children were 2, 5, and 8 weeks (median 2, 12, and 21 days), respectively, and significantly longer in adults -2, 6, and 10 weeks (median 3, 14, and 26 days; p < 10-10 for all comparisons). Thus, longer HVEM than currently used is needed for expanding its clinical value from diagnosis of nonepileptic or very frequent epileptic events to a presurgical tool for patients with drug-resistant epilepsy. Technical developments and further studies are warranted.

Single-molecule studies reveal method for tuning the heterogeneous activity of alkaline phosphatase.

Single-molecule-enzymology (SME) methods have enabled the observation of heterogeneous catalytic activities within a single enzyme population. Heterogeneous activity is hypothesized to originate from conformational changes in the enzyme that result from changes in the local environment leading to catalytically active substates. Here, we use SME to investigate the mechanisms of heterogeneous activity exhibited by tissue nonspecific alkaline phosphatase (TNSALP), which reveals two subpopulations with different catalytic activities. We show the effect of pH and temperature on the distribution of TNSALP activity and confirm the presence of two subpopulations attributed to half- and fully active TNSALP substates. We provide mechanistic insight about protein structure using molecular dynamic simulations and show pH- and temperature-dependent conformational transitions that corroborate experimentally observed changes in TNSALP activity. These results show the utility of SME to understand heterogeneous enzyme activity and demonstrate a simple approach using pH and temperature to tune catalytic activity within an enzyme population.

Ectopic Lymphoid Follicle Formation and Human Seasonal Influenza Vaccination Responses Recapitulated in an Organ-on-a-Chip.

Lymphoid follicles (LFs) are responsible for generation of adaptive immune responses in secondary lymphoid organs and form ectopically during chronic inflammation. A human model of ectopic LF formation will provide a tool to understand LF development and an alternative to non-human primates for preclinical evaluation of vaccines. Here, it is shown that primary human blood B- and T-lymphocytes autonomously assemble into ectopic LFs when cultured in a 3D extracellular matrix gel within one channel of a two-channel organ-on-a-chip microfluidic device. Superfusion via a parallel channel separated by a microporous membrane is required for LF formation and prevents lymphocyte autoactivation. These germinal center-like LFs contain B cells expressing Activation-Induced Cytidine Deaminase and exhibit plasma cell differentiation upon activation. To explore their utility for seasonal vaccine testing, autologous monocyte-derived dendritic cells are integrated into LF Chips. The human LF chips demonstrate improved antibody responses to split virion influenza vaccination compared to 2D cultures, which are enhanced by a squalene-in-water emulsion adjuvant, and this is accompanied by increases in LF size and number. When inoculated with commercial influenza vaccine, plasma cell formation and production of anti-hemagglutinin IgG are observed, as well as secretion of cytokines similar to vaccinated humans over clinically relevant timescales.

Severe Acute Respiratory Syndrome Coronavirus 2 Antigens as Targets of Antibody Responses.

Humoral immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during acute infection and convalescence has been widely studied since March 2020. In this review, the authors summarize literature on humoral responses to SARS-CoV-2 antigens with a focus on spike, nucleocapsid, and the receptor-binding domain as targets of antibody responses. They highlight serologic studies during acute SARS-CoV-2 infection and discuss the clinical relevance of antibody levels in COVID-19 progression. Antibody responses in pediatric COVID-19 patients are also reviewed. Finally, the authors discuss antibody responses during convalescence and their role in protection from SARS-CoV-2 reinfection.

Zonulin Antagonist, Larazotide (AT1001), As an Adjuvant Treatment for Multisystem Inflammatory Syndrome in Children: A Case Series.

OBJECTIVES: A recent study suggests that Multisystem Inflammatory Syndrome in Children (MIS-C) is triggered by gastrointestinal breach of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral particles from the gut lumen into systemic circulation. The virus remains in the gut weeks to months after respiratory infection, causing zonulin release from the intestinal epithelial cells. Zonulin loosens tight junctions, permitting trafficking of highly inflammatory viral particles into circulation. Current MIS-C treatments target the subsequent immune hyperactivation, not the causative loss of mucosal barrier integrity. Larazotide, a zonulin inhibitor, prevents breakdown of tight junctions, limiting antigen trafficking. DESIGN: Children with MIS-C were treated with larazotide as an adjuvant to steroid/intravenous immunoglobulin therapy. Clinical outcomes, SARS-CoV-2 antigenemia, and cytokine profiles are reported. Outcomes were compared with children with MIS-C receiving steroids and/or IVIG therapy alone. PATIENTS: Four children with MIS-C, ages 3-17 years, were enrolled. INTERVENTIONS: Patients were treated with open label larazotide 10 mcg/kg (maximum 500 mcg/dose) orally four times daily for 21 days. MEASUREMENTS AND MAIN RESULTS: All four patients tolerated larazotide without adverse effects and displayed reduction in Spike antigenemia to undetectable levels. When compared with 22 children with MIS-C receiving steroids and/or intravenous immunoglobulin therapy alone, larazotide-treated patients reported significantly improved time to resolution of gastrointestinal symptoms (p = 0.03), and time to clearance of Spike antigenemia (p = 0.04), plus a trend towards shorter length of stay. CONCLUSIONS: Larazotide appears safe and well-tolerated and may offer potential benefit as an adjuvant to immune-targeted therapies. Expansion of clinical trials is urgently needed to ascertain the clinical impact of larazotide on MIS-C.

High-Sensitivity Single Molecule Array Assays for Pathological Isoforms in Parkinson's Disease.

BACKGROUND: Clinical trials for neurodegenerative diseases are increasingly utilizing measurements of post-translational modifications (PTMs) and pathological isoforms as surrogate markers of target engagement and therapeutic efficacy. These isoforms, however, tend to exist at femtomolar concentrations, well below the detection limit of conventional immunoassays. Therefore, highly sensitive and well-validated assays for these isoforms are needed. METHODS: We developed a novel panel of single molecule array assays for pathological isoforms and PTMs implicated in the development and pathophysiology of Parkinson's disease. We validated this panel by measuring these analytes in the cerebrospinal fluid of a cross-sectional cohort of 100 patients with Parkinson's disease and 100 healthy controls. RESULTS: When comparing patients with Parkinson's disease to healthy controls, alpha synuclein, pSer129 alpha synuclein, DJ-1, and C-reactive protein were shown to be reduced in patients with Parkinson's disease while p396 tau and neurofilament light chain were shown to be increased. A random forest analysis produced an area under the curve of 0.70 for the panel. CONCLUSIONS: Measurement of post-translational modifications and pathological isoforms in patients with Parkinson's disease improved diagnostic accuracy above that of total protein measurements, demonstrating the potential utility of these assays for monitoring patients in clinical trials.

Single-Molecule Enzymology for Diagnostics: Profiling Alkaline Phosphatase Activity in Clinical Samples.

Enzymes can be used as biomarkers for a variety of diseases. However, profiling enzyme activity in clinical samples is challenging due to the heterogeneity in enzyme activity, and the low abundance of the target enzyme in biofluids. Single-molecule methods can overcome these challenges by providing information on the distribution of enzyme activities in a sample. Here, we describe the concept of using the single-molecule enzymology (SME) method to analyze enzymatic activity in clinical samples. We present recent work focused on measuring alkaline phosphatase isotypes in serum samples using SME. Future work will involve improving and simplifying this technology, and applying it to other enzymes for diagnostics.

Digital Semiology: A Prototype for Standardized, Computer-Based Semiologic Encoding of Seizures.

Video-EEG monitoring (VEM) is imperative in seizure classification and presurgical assessment of epilepsy patients. Analysis of VEM is currently performed in most institutions using a freeform report, a time-consuming process resulting in a non-standardized report, limiting the use of this essential diagnostic tool. Herein we present a pilot feasibility study of our experience with "Digital Semiology" (DS), a novel seizure encoding software. It allows semiautomated annotation of the videos of suspected events from a predetermined, hierarchal set of options, with highly detailed semiologic descriptions, somatic localization, and timing. In addition, the software's semiologic extrapolation functions identify characteristics of focal seizures and PNES, sequences compatible with a Jacksonian march, and risk factors for SUDEP. Sixty episodes from a mixed adult and pediatric cohort from one level 4 epilepsy center VEM archives were analyzed using DS and the reports were compared with the standard freeform ones, written by the same epileptologists. The behavioral characteristics appearing in the DS and freeform reports overlapped by 78-80%. Encoding of one episode using DS required an average of 18 min 13 s (standard deviation: 14 min and 16 s). The focality function identified 19 out of 43 focal episodes, with a sensitivity of 45.45% (CI 30.39-61.15%) and specificity of 87.50% (CI 61.65-98.45%). The PNES function identified 6 of 12 PNES episodes, with a sensitivity of 50% (95% CI 21.09-78.91%) and specificity of 97.2 (95% CI 88.93-99.95%). Eleven events of GTCS triggered the SUDEP risk alert. Overall, these results show that video recordings of suspected seizures can be encoded using the DS software in a precise manner, offering the added benefit of semiologic alerts. The present study represents an important step toward the formation of an annotated video archive, to be used for machine learning purposes. This will further the goal of automated VEM analysis, ultimately contributing to wider utilization of VEM and therefore to the reduction of the treatment gap in epilepsy.

A Modular Biomaterial Scaffold-Based Vaccine Elicits Durable Adaptive Immunity to Subunit SARS-CoV-2 Antigens.

The coronavirus disease 2019 (COVID-19) pandemic demonstrates the importance of generating safe and efficacious vaccines that can be rapidly deployed against emerging pathogens. Subunit vaccines are considered among the safest, but proteins used in these typically lack strong immunogenicity, leading to poor immune responses. Here, a biomaterial COVID-19 vaccine based on a mesoporous silica rods (MSRs) platform is described. MSRs loaded with granulocyte-macrophage colony-stimulating factor (GM-CSF), the toll-like receptor 4 (TLR-4) agonist monophosphoryl lipid A (MPLA), and SARS-CoV-2 viral protein antigens slowly release their cargo and form subcutaneous scaffolds that locally recruit and activate antigen-presenting cells (APCs) for the generation of adaptive immunity. MSR-based vaccines generate robust and durable cellular and humoral responses against SARS-CoV-2 antigens, including the poorly immunogenic receptor binding domain (RBD) of the spike (S) protein. Persistent antibodies over the course of 8 months are found in all vaccine configurations tested and robust in vitro viral neutralization is observed both in a prime-boost and a single-dose regimen. These vaccines can be fully formulated ahead of time or stored lyophilized and reconstituted with an antigen mixture moments before injection, which can facilitate its rapid deployment against emerging SARS-CoV-2 variants or new pathogens. Together, the data show a promising COVID-19 vaccine candidate and a generally adaptable vaccine platform against infectious pathogens.