Vaccine Efficacy Research Articles

Serological responses to target Streptococcus pyogenes vaccine antigens in patients with proven invasive beta-haemolytic streptococcal infections.

Rising incidence of invasive beta-haemolytic streptococcal (iBHS) infections has prompted consideration of vaccination as a preventative strategy for at-risk populations. The benefits of a vaccine targeting Lancefield group A (Streptococcus pyogenes; Strep A) would increase if cross-species immunity against Lancefield groups C/G (Streptococcus dysgalactiae subspecies equisimilis; SDSE) and B (Streptococcus agalactiae; GBS) was demonstrated. A prospective, observational study of adult patients with iBHS infections due to Strep A, SDSE or GBS. Antibody responses to six Strep A candidate antigens were assayed on acute and convalescent sera. A serological response was defined as an increase of >0.2log10 arbitrary units/mL (AU/mL). Sixty-seven participants were enrolled. Thirty-three participants were included in the final analysis (12, 11 and 10 with Strep A, SDSE and GBS, respectively). The median serological response for participants with Strep A was significant for all tested antigens (median >0.2log10 difference between acute and convalescent samples; P<0.05 for all). Those with SDSE had comparable and significant median (IQR) responses to streptolysin-O (0.65 [0.36-1.67], P=0.004), S. pyogenes adhesion and division protein (0.68 [0.36-1.63], P=0.005) and C5a peptidase (ScpA; 0.30 [0.23-1.06]), P=0.004). GBS responses were limited to ScpA only (0.34 [0.08-0.52], P=0.05). Patients with invasive Strep A infection mount robust antibody responses to six non-M protein vaccine candidate antigens. Similar significant responses to C5a peptidase in those with invasive SDSE and GBS infection highlight the importance of further research into cross-species protection and immunological correlates of vaccine efficacy.

Prospects of universal influenza virus vaccine and the current challenges of new antiviral drugs

The profound impact of influenza viruses on human health persists as a significant burden, given their potent capacity to cause morbidity and mortality. Despite efforts to mitigate the annual burden of influenza, the effectiveness of current seasonal vaccines in providing substantial protection falls short, leaving undesirable pandemic of influenza viruses. The challenges posed by the influenza pandemic lies from the constant changes inherent in the virus itself, as well as the limitations of current immunization approaches in achieving sufficient immunogenicity. Influenza viruses exhibit antigenic drift and shift, undergoing antigenic evolution by altering the surface glycoproteins. These changes contribute to the persistent and dynamic nature of the influenza virus, posing formidable challenges to effective prevention and control strategies. Currently, there is growing recognition of unique viral targets that hold promise development of broad-protective vaccines against influenza. These targets are distinct from traditional vaccine targets and offer the potential for more comprehension protection against diverse strains of the virus. Here, we present a review about the novel drugs and vaccines that target the influenza virus would signify the unique immune correlates of protection that need to be initiated to accelerate the vaccine efficacy.

Immunogenicity and Protectivity of Sputnik V Vaccine in hACE2-Transgenic Mice against Homologous and Heterologous SARS-CoV-2 Lineages Including Far-Distanced Omicron BA.5

Background: The SARS-CoV-2 virus continuously acquires mutations, leading to the emergence of new variants. Notably, the effectiveness of global vaccination efforts has significantly declined with the rise and spread of the B.1.1.529 (Omicron) variant. Methods: The study used virological, immunological and histological research methods, as well as methods of working with laboratory animals. In this study, we evaluated the Gam-COVID-Vac (Sputnik V), an adenoviral vaccine developed by the N.F. Gamaleya National Research Center for Epidemiology and Microbiology, and conducted experiments on hemizygous K18-ACE2-transgenic F1 mice. The variants studied included B.1.1.1, B.1.1.7, B.1.351, B.1.1.28/P.1, B.1.617.2, and B.1.1.529 BA.5. Results: Our findings demonstrate that the Sputnik V vaccine elicits a robust humoral and cellular immune response, effectively protecting vaccinated animals from challenges posed by various SARS-CoV-2 variants. However, we observed a notable reduction in vaccine efficacy against the B.1.1.529 (Omicron BA.5) variant. Conclusions: Our results indicate that ongoing monitoring of emerging mutations is crucial to assess vaccine efficacy against new SARS-CoV-2 variants to identify those with pandemic potential. If protective efficacy declines, it will be imperative to develop new vaccines tailored to current variants of the virus.

Improved influenza vaccine responses after expression of multiple viral glycoproteins from a single mRNA.

Influenza viruses cause substantial morbidity and mortality every year despite seasonal vaccination. mRNA-based vaccines have the potential to elicit more protective immune responses, but for maximal breadth and durability, it is desirable to deliver both the viral hemagglutinin and neuraminidase glycoproteins. Delivering multiple antigens individually, however, complicates manufacturingand increases cost, thus it would be beneficial to express both proteins from a single mRNA. Here, we develop an mRNA genetic configuration that allows the simultaneous expression of unmodified, full-length NA and HA proteins from a single open reading frame. We apply this approach to glycoproteins from contemporary influenza A and B viruses and, after vaccination, observe high levels of functional antibodies and protection from disease in female mouse and male ferret challenge models. This approach may further efforts to utilize mRNA technology to improve seasonal vaccine efficacy by efficiently delivering multiple viral antigens simultaneously and in their native state.

A Narrative Review on the Pandemic Zoonotic RNA Virus Infections Occurred During the Last 25 Years.

Pandemic zoonotic RNA virus infections have continued to threaten humans and animals worldwide. The objective of this review was to highlight the epidemiology and socioeconomic impacts of pandemic zoonotic RNA virus infections that occurred between 1997 and 2021. Literature search was done from Web of Science, PubMed, Google Scholar and Scopus databases, cumulative case fatalities of individual viral infection calculated, and geographic coverage of the pandemics were shown by maps. Seven major pandemic zoonotic RNA virus infections occurred from 1997 to 2021 and were presented in three groups: The first group consists of highly pathogenic avian influenza (HPAI-H5N1) and swine-origin influenza (H1N1) viruses with cumulative fatality rates of 53.5% and 0.5% in humans, respectively. Moreover, HPAI-H5N1 infection caused 90-100% death in poultry and economic losses of >$10billion worldwide. Similarly, H1N1 caused a serious infection in swine and economic losses of 0.5-1.5% of the Gross Domestic Product (GDP) of the affected countries. The second group consists of severe acute respiratory syndrome-associated coronavirus infection (SARS-CoV), Middle East Respiratory Syndrome (MERS-CoV) and Coronavirus disease 2019 (COVID-19) with case fatalities of 9.6%, 34.3% and 2.0%, respectively in humans; but this group only caused mild infections in animals. The third group consists of Ebola and Zika virus infections with case fatalities of 39.5% and 0.02%, respectively in humans but causing only mild infections in animals. Similar infections are expected in the near future, and hence strict implementation of conventional biosecurity-based measures and development of efficacious vaccines would help minimize the impacts of the next pandemic infection.

Adenoviral fiber-knob based vaccination elicits efficient neutralizing antibodies and T cell responses against adenovirus infection

BackgroundHuman adenoviruses (HAdVs) frequently cause common respiratory or gastrointestinal infections among children, adults, individuals with immune deficiencies, and other vulnerable populations with varying degree of symptoms, ranging from mild to server, and in some cases, even fatalities. Despite the significant clinical impact of HAdVs, there is currently no approved vaccine available.MethodsThis study explores the potential of the adenovirus type 5 fiber knob (Ad5-FK) to stimulate the production of Ad-specific neutralizing antibodies and T-cell responses in mice. Based on structure predictions, we first expressed Ad5-FK in E. coli and confirmed the assembly of FK into its trimeric form. After testing the binding capability of the trimeric FK to susceptible cells, the immunogenicity of the protein in combination with the c-di-AMP adjuvant was assessed in BALB/c mice.ResultsThe purified Ad5-FK exhibited self-trimerization and maintained correct conformation akin to the authentic FK structure. This facilitated effective binding to susceptible HEK293 cells. Notably, the protein demonstrated significant inhibition of HEK293 cells infection by rAd5-GFP. Immunization of BALB/c mice with Ad5-FK, or Ad5-FK mixed with c-di-AMP yielded FK-specific antibodies with potent neutralization capacity. Significantly, Ad5-FK was found to elicit a vigorous CD4+ T-cell response in the immunized mice.ConclusionOur findings underscore the efficacy of FK-based vaccine in eliciting anti-Ad humoral immune response and CD4 T-cell immune reactions essential for protection against viral infections.

Preclinical immunogenicity and safety of hemagglutinin-encoding modRNA influenza vaccines

Seasonal epidemics of influenza viruses are responsible for a significant global public health burden. Vaccination remains the most effective way to prevent infection; however, due to the persistence of antigenic drift, vaccines must be updated annually. The selection of vaccine strains occurs months in advance of the influenza season to allow adequate time for production in eggs. RNA vaccines offer the potential to accelerate production and improve efficacy of influenza vaccines. We leveraged the nucleoside-modified RNA (modRNA) platform technology and lipid nanoparticle formulation process of the COVID-19 mRNA vaccine (BNT162b2; Comirnaty®) to create modRNA vaccines encoding hemagglutinin (HA) (modRNA-HA) for seasonal human influenza strains and evaluated their preclinical immunogenicity and toxicity. In mice, a monovalent modRNA vaccine encoding an H1 HA demonstrated robust antibody responses, HA-specific Th1-type CD4+ T cell responses, and HA-specific CD8+ T cell responses. In rhesus and cynomolgus macaques, the vaccine exhibited durable functional antibody responses and HA-specific IFN-γ+ CD4+ T cell responses. Immunization of mice with monovalent, trivalent, and quadrivalent modRNA-HA vaccines generated functional antibody responses targeting the seasonal influenza virus(es) encoded in the vaccines that were greater than, or similar to, those of a licensed quadrivalent influenza vaccine. Monovalent and quadrivalent modRNA-HA vaccines were well-tolerated by Wistar Han rats, with no evidence of systemic toxicity. These nonclinical immunogenicity and safety data support further evaluation of the modRNA-HA vaccines in clinical studies.

Safety and efficacy of COVID-19 vaccines in children and adolescents with cancer.

Children with cancer have a higher morbidity and mortality due to COVID-19. Vaccination of children with cancer is important. In this study, we aimed to investigate the effectiveness and side effects of the COVID-19 vaccines in children and adolescents with cancer. Fifty-eight patients from four centers were included in the study. Antibodies to the SARS-CoV-2 spike protein levels were measured. Vaccine-related complaints were recorded. There were 33 male and 25 female patients. The mean age was 16.9±2.3 years. In 58.6% of cases, the diagnosis was hematological malignancies. Twenty patients were currently under treatment, while 38 had completed the treatment. Forty-eight patients received chemotherapy ± radiotherapy, 13 received immunotherapy, and 3 underwent stem cell transplantation. CoronoVac© and BNT162b2© vaccines were administered in 24% and 76%, respectively. The mean antibody level was lower in patients who received CoronaVac© than that of BNT162b2©, although the difference was not significant. The levels were within the protective limits in both groups. No significant difference was found in antibody levels according to diagnostic subgroups, treatment status, type of treatment, line of treatment, disease status and time between vaccines and measurement of antibody level. The most common side effects were pain at the injection site (37.9%) and malaise/weakness (17.2%), which were similar for both vaccines. Our study showed that both mRNA and inactivated vaccines elicit an immune response in children with cancer. However, the seroconversion rate is significantly higher in mRNA vaccines. Side effects were similar to those seen in healthy children.

Optimized Fabrication of Dendritic Mesoporous Silica Nanoparticles as Efficient Delivery System for Cancer Immunotherapy.

In the past decade, cancer immunotherapy has revolutionized the field of oncology. Major immunotherapy approaches such as immune checkpoint inhibitors, cancer vaccines, adoptive cell therapy, cytokines, and immunomodulators have shown great promise in preclinical and clinical settings. Among them, immunomodulatory agents including cancer vaccines are particularly appealing; however, they face limitations, notably the absence of efficient and precise targeted delivery of immune-modulatory agents to specific immune cells and the potential for off-target toxicity. Nanomaterials can play a pivotal role in addressing targeting and other challenges in cancer immunotherapy. Dendritic mesoporous silica nanoparticles (DMSNs) can enhance the efficacy of cancer vaccines by enhancing the effective loading of immune modulatory agents owing to their tunable pore sizes. In this work, an emulsion-based method is optimized to customize the pore size of DMSNs and loaded DMSNs with ovalbumin (OVA) and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (CpG-OVA-DMSNs). The immunotherapeutic effect of DMSNs is achieved through controlled chemical release of OVA and CpG in antigen-presenting cells (APCs). The results demonstrated that CpG-OVA-DMSNs efficiently activated the immune response in APCs and reduced tumor growth in the murine B16-OVA tumor model.

Switching from a 2-dose to a 1-dose program of gender-neutral routine vaccination against human papillomavirus in Canada: a mathematical modelling analysis.

Worldwide, countries are examining whether to implement 1-dose human papillomavirus (HPV) vaccination instead of using 2 doses. To inform policy, we sought to project the population-level impact and efficiency of switching from 2-dose to 1-dose gender-neutral routine HPV vaccination in Canada. We used HPV-ADVISE, an individual-based transmission-dynamic model of HPV infections and diseases, to mathematically model vaccination programs in 2 provinces, Quebec, a province with high HPV vaccination coverage (around 85%), and Ontario, which has lower coverage (around 65%). We examined non-inferior and pessimistic scenarios of the efficacy (vaccine efficacy of 98% or 90%) and average vaccine duration (lifelong, 30 yr, or 25 yr) of 1 dose compared with 2 doses (98% vaccine efficacy, lifelong vaccine duration). Our main outcomes were the relative reduction in HPV-16 (by sex) and cervical cancers, and the number of doses needed to prevent 1 cervical cancer. Our model projected that 1-dose HPV vaccination would avert a similar number of cervical cancers as 2 doses in Canada, under various scenarios. Under the most pessimistic scenario (25-yr vaccine duration), 1-dose vaccination would avert fewer cervical cancers than 2 doses, by about 3 percentage points over 100 years. All 1-dose scenarios were projected to lead to elimination of cervical cancer (< 4 cervical cancers/100 000 female-years) and to be a substantially more efficient use of vaccine doses than a 2-dose scenario (1-dose v. no vaccination = 800-1000 doses needed to prevent 1 cervical cancer; incremental doses for 2-dose v. 1-dose vaccination > 10 000 doses needed to prevent 1 additional cervical cancer). If the average duration of 1-dose protection is longer than 25 years, a 1-dose HPV vaccination program would protect those vaccinated during their peak ages of sexual activity and prevent a similar number of HPV-related cancers as a 2-dose program, while being a more efficient use of vaccine doses.

Effective Synthesis of mRNA during In Vitro Transcription with Fewer Impurities Produced.

The remarkable efficacy of COVID-19 vaccines has established mRNA as a highly promising biomedical technology. However, the adequate application of mRNA therapeutics necessitates additional measures to mitigate the inherent immunogenicity, which is predominantly caused by dsRNA. As a byproduct of the in vitro transcription of mRNA, dsRNA was reported to be originated through several distinct mechanisms, including the extension of 3' loop-back hairpins, the extension of hybridized abortive transcripts, and promoter-independent transcription. The intricate mechanisms involved pose a dilemma as the reduction in dsRNA results in a concomitant decrease in other critical quality attributes of mRNA. Here, we demonstrate that the promoter binding motifs of T7 RNA polymerase directly impact the production of promoter-independent transcription-based dsRNA. Specifically, the G753A mutation significantly reduces the formation of dsRNA byproducts, which can further combine with modified nucleotides to enhance the effectiveness of dsRNA mitigation and with previously reported high-integrity mutation K389A to minimize side effects. Accordingly, the present study reports a cost-effective approach to synthesize high-purity, less immunostimulatory mRNA by using an engineered T7 RNA polymerase mutant.

6684 Multi-Dose BCG Vaccination for Protection Against COVID-19 Disease and Other Respiratory Infections in Subjects with Type 1 Diabetes Late in the US Pandemic

Abstract Disclosure: W. Kühtreiber: None. E. Hostetter: None. G.E. Wolfe: None. M. Vaishnaw: None. R. Goldstein: None. E. Bulczynski: None. N. Hullavarad: None. J.E. Braley: None. H. Zheng: None. D.L. Faustman: None. A Phase II clinical trial previously reported that multiple doses of the bacillus Calmette-Guerin (BCG) vaccine, originally developed for tuberculosis prevention, could protect at-risk individuals with type 1 diabetes (T1D) against COVID-19 disease and infectious diseases early in the pandemic in the United States (US) (Cell Rep Med 2022). As SARS-CoV-2 evolved, COVID-19 disease became more transmissible, but less lethal. In a new, Phase III, randomized, double-blinded, placebo-controlled trial, we tested whether at-risk individuals with T1D given multi-dose, intradermal BCG would be protected against COVID-19 and other infectious diseases (2:1 randomization; BCG: n=93; placebo: n=48). The trial was conducted late in the COVID-19 pandemic during sequential dominance of Beta, Gamma, Delta and Omicron variants. All participants were US citizens and were negative for prior BCG vaccination and negative for tuberculosis. Two co-primary endpoints were protection from COVID-19 disease and platform protection from all infectious diseases. From April 2021 to November 2022, Tokyo-strain BCG vaccination provided significant protection against COVID-19 disease (p=0.023) and strong platform protection against all infectious diseases (p&amp;lt;0.0001). Over the 19-month course of the study, commercial COVID-19 vaccines were rolled out. An observational analysis of the placebo control group (i.e., no BCG vaccination) showed that COVID-19 mRNA vaccination alone provided no protection from COVID-19 disease in the enrolled population (p=0.43). BCG vaccination efficacy against COVID-19 and infectious disease in T1D was unaffected by concurrent COVID-19 vaccinations (observational analysis). These data suggest that BCG has efficacy against a range of SARS-CoV-2 variants, in contrast to current COVID-19 vaccines, which have narrow efficacy against specific viral variants. Further, it shows that individuals with T1D represent a vulnerable population for whom BCG appears to be the only effective vaccine against COVID-19 disease and confirms that, in the US, BCG vaccination protects against infectious disease as well. Presentation: 6/3/2024

Enhanced anti-tumor efficacy of electroporation (EP)-mediated DNA vaccine boosted by allogeneic lymphocytes in pre-established tumor models

BackgroundTumor-reactive T cells play a crucial role in anti-tumor responses, but T cells induced by DNA vaccination are time-consuming processes and exhibit limited anti-tumor efficacy. Therefore, we evaluated the anti-tumor effectiveness of reactive T cells elicited by electroporation (EP)-mediated DNA vaccine targeting epidermal growth factor receptor variant III (pEGFRvIII plasmid), in conjunction with adoptive cell therapy (ACT), involving the transfer of lymphocytes from a pEGFRvIII EP-vaccinated healthy donor.MethodsThe validation of the established pEGFRvIII plasmid and EGFRvIII-positive cell model was confirmed through immunofluorescence and western blot analysis. Flow cytometry and cytotoxicity assays were performed to evaluate the functionality of antigen-specific reactive T cells induced by EP-mediated pEGFRvIII vaccines, ACT, or their combination. The anti-tumor effectiveness of EP-mediated pEGFRvIII vaccines alone or combined with ACT was evaluated in the B16F10-EGFRvIII tumor model.ResultsEP-mediated pEGFRvIII vaccines elicited serum antibodies and a robust cellular immune response in both healthy and tumor-bearing mice. However, this response only marginally inhibited early-stage tumor growth in established tumor models. EP-mediated pEGFRvIII vaccination followed by adoptive transfer of lymphocytes from vaccinated healthy donors led to notable anti-tumor efficacy, attributed to the synergistic action of antigen-specific CD4+ Th1 cells supplemented by ACT and antigen-specific CD8+ T cells elicited by the EP-mediated DNA vaccination.ConclusionsOur preclinical studies results demonstrate an enhanced anti-tumor efficacy of EP-mediated DNA vaccination boosted with adoptively transferred, vaccinated healthy donor-derived allogeneic lymphocytes.

The Effects of Numerical Evidence and Message Framing in Communicating Vaccine Efficacy

To examine the effects of numerical evidence and message framing in communicating vaccine efficacy information about infectious diseases, an online experiment presented to U.S. adults different versions of a vaccination promotional message that vary by numerical vaccine efficacy evidence: (low efficacy rate: 60% vs. high efficacy rate: 95%), outcome framing (preventing disease-related infection vs. preventing disease-related severe illness), and gain vs. loss framing, using a factorial between-subjects design. While there was no significant interaction between numerical vaccine efficacy evidence and message framing, findings showed that a higher vaccine efficacy rate increased positive beliefs about vaccination and outcome framing emphasizing infection prevention increased message processing fluency. Given that infectious diseases pose higher risks for severe illness among older adults, follow-up analyses by age showed that only younger adults were sensitive to message framing where outcome framing emphasizing infection prevention increased processing fluency.

Machine learning tools used for mapping some immunogenic epitopes within the major structural proteins of the bovine coronavirus (BCoV) and for the in silico design of the multiepitope-based vaccines.

BCoV is one of the significant causes of enteritis in young calves; it may also be responsible for many respiratory outbreaks in young calves. BCoV participates in the development of bovine respiratory disease complex in association with other bacterial pathogens. Our study aimed (1) to map the immunogenic epitopes (B and T cells) within the major BCoV structural proteins. These epitopes are believed to induce a robust immune response through the interaction with major histocompatibility complex (MHC class II) molecules (2) to design some novel BCoV multiepitope-based vaccines. The goal is achieved through several integrated in silico prediction computational tools to map these epitopes within the major BCoV structural proteins. The final vaccine was constructed in conjugation with the Choleratoxin B toxin as an adjuvant. The tertiary structure of each vaccine construct was modeled through the AlphaFold2 tools. The constructed vaccine was linked to some immunostimulants such as Toll-like receptors (TLR2 and TLR4). We also predicted the affinity binding of these vaccines with this targeted protein using molecular docking. The stability and purity of each vaccine construct were assessed using the Ramachandran plot and the Z-score values. We created the in silico cloning vaccine constructs using various expression vectors through vector builder and Snap gene. The average range of major BCoV structural proteins was detected within the range of 0.4 to 0.5, which confirmed their antigen and allergic properties. The binding energy values were detected between -7.9 and -9.4 eV and also confirmed their best interaction between our vaccine construct and Toll-like receptors. Our in silico cloning method expedited the creation of vaccine constructs and established a strong basis for upcoming clinical trials and experimental validations. Our designed multiepitope vaccine candidates per each BCoV structural protein showed high antigenicity, immunogenicity, non-allergic, non-toxic, and high-water solubility. Further studies are highly encouraged to validate the efficacy of these novel BCoV vaccines in the natural host.

Novel vaccines against lung cancer.

Despite recent advances in immunotherapy treatment for metastatic, early-stage nonsmall cell lung cancer (NSCLC), palliative, adjuvant, neoadjuvant, and perioperative treatment options, further development is needed. Exploring new frontiers of immuno-oncology is necessary. Researchers are interested in a therapeutic vaccination model. In this paper, we provide a review of the latest lung cancer therapeutic vaccines.We describe strategies for antigen selection and delivery platforms. As of 5th of August 2024, we have reviewed ongoing clinical trials and results.We summarize most of the important clinical trials of novel vaccines, the way of action, and available clinical data. We also discuss the pros and cons of various types of therapeutic vaccines. Until recently, clinical trial results were mixed regarding the efficacy of therapeutic vaccines in lung cancer.Developing next-generation sequencing and bioinformatic technologies has helped identify suitable antigens. New personalized vaccines are based on neoantigens specific to unique tumor mutations.Neoantigens, instead of tumor-associated antigens, better delivery systems and adjuvants will improve antigen presentation and immune system activation.Combining these therapeutic vaccines with other therapeutic approaches will improve and prolong the response.

B-043 Q-nab™ Igg kit: verification and validation of a novel cell-free quantitative neutralizing antibody assay

Abstract Background As the world exits the COVID-19 pandemic era, it is very important to assess population-level and individual seroprotectivity against multiple circulating and emerging SARS-CoV-2 strains, especially in vulnerable populations. Current serological measurements for neutralizing antibodies (NAbs) are either done using complex and time-intensive pseudovirus- or micro-neutralization assays or as a high throughput competitive ELISA assay. These assays, by design, cannot be multiplexed to measure NAb titers against multiple strains and suffer from a limited dynamic range. The Q-NAb IgG Tests, which rely on blocking the non-neutralizing antibodies (NNAbs) using a novel fusion protein, were developed and validated to quantitatively measure NAb titer against the SARS-CoV-2 strains used to develop the first two mRNA vaccines viz. ancestral and BA.4/5 strains. Methods The Q-NAb assay measures the NAb titer in a sample by first sequestering the NNAbs using the fusion protein (made by covalently coupling SARS-CoV-2 BA.4/5 RBD and h-ACE2 protein) thereby enriching the NAbs in the sample. Variant-specific NAbs are then detected using an indirect ELISA where the wells are coated with the variant RBD and yield a signal that is directly proportional to the concentration of NAb. Clinical samples from subjects that have either had a SARS-CoV-2 infection (N=27), taken the initial vaccine series (N=123) and/or the bivalent booster (N=151) and pre-pandemic samples (N=29) were commercially sourced. Q-NAb NAb titers were measured using the ancestral and BA.4/5 kits and were compared against corresponding MN50 values using both parametric and non-parametric models. Single-site precision, low-end sensitivity, dilutional linearity, and interference screening of Q-NAb IgG Kits were evaluated in accordance with appropriate CLSI guidelines. Traceability and total uncertainty of the Q-NAb IgG Kits (Ancestral and BA.4/5) to WHO International Standard 21/340 and 21/338 respectively was established using a calibration hierarchy adapted from ISO 17511:2020. Results Both the ancestral and BA.4/5 Q-NAb IgG Test Kits correlated with MN50 titers with a Spearman correlation coefficient of 0.90 and 0.89 respectively. The total uncertainty in traceability of calibration to WHO International standards 21/340 and 21/338 was found to be less than 10% for both tests. Single site precision across the assay range for BA.4/5 kit was found to be 6-10% with a limit of quantitation of 312 IU/mL. Assays exhibited dilutional linearity across their respective dynamic range and had no significant interference from common endogenous and exogenous substances. Conclusions We have successfully validated the novel Q-NAb IgG neutralization assay platform as individual assays for measuring neutralizing titers against ancestral and BA.4/5 SARS-CoV-2 strains. The assays have expanded dynamic range, excellent analytical performance and correlation to accepted gold-standard microneutralization assays. Both assays are calibrated and traceable to WHO international standards, thereby enabling the compilation and comparison of data from multiple clinical cohorts run across multiple laboratories. The design of the Q-NAb IgG Test kit makes it amenable to multiplexing (for example, on an MSD platform) to assess neutralization titers against multiple variants at the same time. Such a multiplexed platform can be used to assess vaccine efficacy and seroprotection against multiple variants including emerging variants.

ELISA-R: an R-based method for robust ELISA data analysis.

Enzyme-linked immunosorbent assay (ELISA) is a technique to detect the presence of an antigen or antibody in a sample. ELISA is a simple and cost-effective method that has been used for evaluating vaccine efficacy by detecting the presence of antibodies against viral/bacterial antigens and diagnosis of disease stages. Traditional ELISA data analysis utilizes a standard curve of known analyte, and the concentration of the unknown sample is determined by comparing its observed optical density against the standard curve. However, in the case of vaccine research for complicated bacteria such as Mycobacterium tuberculosis (Mtb), there is no prior information regarding the antigen against which high-affinity antibodies are generated and therefore plotting a standard curve is not feasible. Consequently, the analysis of ELISA data in this instance is based on a comparison between vaccinated and unvaccinated groups. However, to the best of our knowledge, no robust data analysis method exists for "non-standard curve" ELISA. In this paper, we provide a straightforward R-based ELISA data analysis method with open access that incorporates end-point titer determination and curve-fitting models. Our modified method allows for direct measurement data input from the instrument, cleaning and arranging the dataset in the required format, and preparing the final report with calculations while leaving the raw data file unchanged. As an illustration of our method, we provide an example from our published data in which we successfully used our method to compare anti-Mtb antibodies in vaccinated vs non-vaccinated mice.

Atypical Mumps; are We Heading Towards an Outbreak?

Mumps, caused by the mumps virus, is a contagious disease primarily affecting children and young adults. While typically presenting with salivary gland swelling and systemic symptoms, mumps can lead to various complications including SNHL, orchitis/ oophoritis, aseptic meningitis. Recent observations suggest atypical features in mumps cases, raising concerns of a potential outbreak in India. To discuss the etiopathogenesis and clinical presentation in cases of atypical mumps with increasing number of cases, a prospective multicentric study was conducted across five major centers - SMS Medical College Jaipur, RDBP Jaipuria Hospital, Jaipur, Shri Ashwini Saxena ENT Hospital Rewari, AIIMS Bhubaneswar and SP Medical College Bikaner, in India to evaluate patients with acute salivary gland swellings. Clinical and laboratory data were collected, including demographics, presenting symptoms, history of vaccination, imaging findings, and treatment outcomes. Patients were followed for four weeks post-treatment to monitor for delayed complications. Among 53 patients, a bimodal age distribution was observed, with peaks in early adolescents and middle-aged individuals. Vaccination status was recorded based on recall. Fever and salivary gland swelling were predominant symptoms, with a significant proportion experiencing submandibular gland involvement. Elevated serum amylase and CRP levels correlated with disease severity and prolonged symptomatic resolution. Notably, cases of sensorineural hearing loss (SNHL) and airway complications emerged as significant concerns. The study highlights a shift in mumps demographics, with higher age groups affected and increased incidence of complications like SNHL and airway compromise. International trends also suggest periodic outbreaks and evolving clinical manifestations post-COVID-19 pandemic. Factors contributing to mumps resurgence include lack of vaccination or vaccine efficacy, population immunity, and seasonal variations. India appears to be facing a potential mumps outbreak, characterized by atypical features and increased risk of complications like SNHL and airway compromise. Serum amylase and CRP serve as valuable markers for disease severity. Early recognition and management of complications are crucial, emphasizing the importance of mumps immunization to mitigate the impact of the disease. ENT specialists should remain vigilant for emerging complications, particularly SNHL, advocating for comprehensive immunization strategies.

Development of prediction models of COVID-19 vaccine uptake among Lebanese and Syrians in a district of Beirut, Lebanon: a population-based study

IntroductionVaccines are essential to prevent infection and reduce the morbidity of infectious diseases. Previous evidence has shown that migrants and refugees are particularly vulnerable to exclusion and discrimination, and low...