Rapid Vaccine Research Articles

Monitoring and tracking the spread of SARS-CoV-2 in Asturias, Spain.

Mutational analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can quantify the relative importance of variants over time, enable dominant mutations to be identified, and facilitate near real-time detection, comparison and tracking of evolving variants. SARS-CoV-2 in Asturias, an autonomous community of Spain with a large ageing population, and high levels of migration and tourism, was monitored and tracked from the beginning of the pandemic in February 2020 until its decline and stabilization in August 2021, and samples were characterized using whole genomic sequencing and single nucleotide polymorphisms. Data held in the GISAID database were analysed to establish patterns in the appearance and persistence of SARS-CoV-2 strains. Only 138 non-synonymous mutations occurring in more than 1 % of the population with SARS-CoV-2 were found, identifying ten major variants worldwide (seven arose before January 2021), 19 regional and one local. In Asturias only 17 different variants were found. After vaccination, no further regional major variants were found. Only half of the defined variants circulated and no new variants were generated, indicating that infection control measures such as rapid diagnosis, isolation and vaccination were efficient.

Ethno-demographic disparities in humoral responses to the COVID-19 vaccine among healthcare workers.

The COVID-19 pandemic had a profound impact on global health, but rapid vaccine administration resulted in a significant decline in morbidity and mortality rates worldwide. In this study, we sought to explore the temporal changes in the humoral immune response against SARS-CoV-2 healthcare workers (HCWs) in Augusta, GA, USA, and investigate any potential associations with ethno-demographic features. Specifically, we aimed to compare the naturally infectedindividuals with naïve individuals to understand the immune response dynamics after SARS-CoV-2 vaccination.A total of 290 HCWs were included and assessed prospectively in this study. COVID status was determined using a saliva-based COVID assay. Neutralizing antibody (NAb) levels were quantified using a chemiluminescent immunoassay system, and IgG levels were measured using an enzyme-linked immunosorbent assaymethod. We examined the changes in antibody levels among participants using different statistical tests including logistic regression and multiple correspondence analysis.Our findings revealed a significant decline in NAb and IgG levels at 8-12 months postvaccination. Furthermore, a multivariable analysis indicated that this decline was more pronounced in White HCWs (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.07-4.08, p = 0.02) and IgG (OR = 2.07, 95% CI = 1.04-4.11, p = 0.03) among the whole cohort. Booster doses significantly increased IgG and NAb levels, while a decline in antibody levels was observed in participants without booster doses at 12 months postvaccination.Our results highlight the importance of understanding the dynamics of immune response and the potential influence of demographic factors on waning immunity to SARS-CoV-2. In addition, our findings emphasize the value of booster doses to ensure durable immunity.

Synthesis and Morphological Control of Fe Metal Particles By Controlling the Metal Complex Condition in Basic Solution

Coronavirus outbreaks have recently necessitated rapid virus recovery and vaccine developments. Magnetic beads are essential components to recover virus in an immunoprecipitation process. Pure iron particles with a diameter of 1 µm can be used as core materials of high-performance magnetic beads.Thus, the development of effective and green synthesis method of Fe nanoparticles is important. However, Fe nanoparticles were synthesized only in acidic solution by using strong reducing reagent, such as NaBH4, while it cannot be achieved in the basic solution since iron hydroxide, which is easily formed in this condition, cannot be reduced into metals. However, former is not suitable for commercial synthesis method because of its intense reducing process. Thus, the reducing rout of Fe species under basic condition should be developed.Here, until now, we tried to synthesis the various metal/alloy nanoparticles, such as Pd20Te7 nanoparticles and uniform Cu-In (CI) alloy nanoparticles, by utilizing the restrict metallic complexes controlling method in an aqueous solution under room temperature. In this method, reduction potential of the metal species can be controlled under the room temperature, consequently metal/alloy nanomaterials with uniform and well crystallized structure can be successfully synthesized.So, in this study, we proposed the synthesis method of iron particles under basic conditions, and morphological conditions control of iron particles by utilizing the “gel-sol” method using gel networks, which is a safe and simple approach to suppress the chain crystallization.Calculation results indicated that Fe complex can be restricted into one species as the function of pH, complexing reagent species and/also concentration. For example, Fe complex can be restricted into single complex in the basic condition (for example 8<pH<11).By using this homogeneous condition, metal Fe nanoparticles were successfully synthesized. The addition of gel networks into the synthesis system can effectively suppress the chain crystallization of iron particles. Furthermore, in order to obtain iron particles with organic-free surface, we proposed a novel method to decompose and remove the gel networks.Other results will present in our presentation. This work was supported by JSPS KAKENHI Grant Number 21H03628 and DOWA holdings.[1] H. Takahashi et.,al, Applied Catalysis A: General 392 (2011) 80–85

InflANNet: a neural network predictor for Influenza A CTL and HTL epitopes to aid robust vaccine design

BackgroundAn efficient and reliable data-driven method is essential to aid robust vaccine design, particularly in the case of an epidemic like Influenza A. Although various prediction tools are existing, most of them focus on the MHC-peptide binding affinity predictions. A tool which can incorporate more features other than binding affinity which characterizes the T-cell epitopes as vaccine candidates would be of much value in this scenario. The objective of this study is to develop two separate neural network models for the predictions of CTLs (cytotoxic T lymphocyte) and HTLs (helper T lymphocyte) with the manually curated datasets as a part of this study from the raw viral sequences of Influenza A.ResultsThe epitope datasets curated from the raw sequences of the broadly protective Neuraminidase protein were utilized for building and training the models for CTLs and HTLs. Each set consisted of nearly a balanced mix of vaccine candidates and non-vaccine candidates for both CTLs and HTLs. These were fed to neural networks as they are proven to be powerful for the predictions when compared with the other machine/deep learning algorithms. A set of epitopes experimentally proved were chosen to validate the model which was also tested through mutational analysis and cross-reactivity. The prepared dataset gave some valuable insights into the epitope distribution statistics and their conservancy in various outbreaks. An idea about the most probable range of peptide-MHC binding affinities was also obtained. Both the models performed well giving high accuracies when validated. These epitopes were checked for cross-reactivity with other antigens upon which it proved to be highly conservative and ideal for vaccine formulation.ConclusionsThe combination of various features and the resulting model efficiencies in turn proved that the collected features are valuable in the easy identification of the vaccine candidates. This suggests that our proposed models have more potential for conserved epitope prediction compared to other existing models trained on similar data and features. The possibility of refining the model with more set threshold values based on more parameters is an added feature that makes it more user driven. Furthermore, the uniqueness of the model due to exclusive set of Neuraminidase epitopes paves a robust way for rapid vaccine design.Graphical abstract

Temporal variations of vaccine hesitancy amid the COVID-19 outbreaks in Hong Kong.

To inform the dynamic adjustments of vaccination campaigns, this study examined the transitions among vaccine hesitancy profiles over the COVID-19 pandemic progression and their predictors and outcomes. The transition patterns among hesitancy profiles over three periods were identified using a latent transition analysis with individuals from a longitudinal cohort study since the emergence of COVID-19 in Hong Kong. Four profiles (i.e., skeptics, apathetics, fence-sitters, and believers) emerged consistently over time. From Period 1 (third and fourth pandemic waves) to Period 2 (dormant period, vaccine rollout), 14.17% of believers became fence-sitters (ambivalization), and 12.11% of fence-sitters became apathetics (apathetization). From Period 2 to Period 3 (omicron surge and vaccine mandates), 20.21% of believers became fence-sitters. Lower trust in government predicted a transition to skepticism, whereas higher trust predicted the opposite. Staying as believers was associated with decreased hygienic and social distancing behavior. The stable hesitancy profiles amid the rapid vaccine uptake suggest that structural factors rather than personal agency may drive the surge. Ambivalization and apathetization may signal disengagement in preventive behaviors. Trust in the government is crucial in the pandemic response. Public health interventions may improve compliance with guidelines and prevent skepticism and apathy.

Coverage survey of typhoid conjugate vaccine among children aged 6 months to 15 years in an urban slum settlement of Lyari Town Karachi, Pakistan.

To estimate the coverage rate of typhoid conjugate vaccine (TCV) among children aged 6 months to 15 years in Lyari Town Karachi, Pakistan. A cross-sectional survey was conducted to estimate the vaccine coverage of Typbar TCV in Lyari Town Karachi utilizing the World Health Organization (WHO) recommended rapid vaccine coverage assessment technique (30 clusters × 7 households). Sampling was powered at town level and multistage cluster sampling was used. Four union councils were randomly selected from a total of 11 and the survey was conducted in those union councils. After consent was obtained, parents of age-eligible children living in the selected union councils were invited to participate in the survey and information was collected on Typbar TCV vaccination status of children aged 6 months to 15 years. Overall, 2325 children were included in the survey. The mean age of the participants was 7.60 ± 3.84 years. The ratio of males to females was equal in the survey sample; 1163 (50.02%) were male. In the total target population, 82% children were found to be vaccinated; however, the vaccination status could be verified for 80%. The vaccine coverage of TCV was comparable among the four union councils and the overall coverage of TCV vaccine in Lyari Town was found to be 80%. The coverage was significantly lower in younger children, 5% and 17% among children aged 6 months to < 2 years and 2 years to < 5 years respectively and 78% among children aged 5 years to 15 years. The overall immunization coverage rate with TCV was found to be satisfactory. Immunization coverage was comparable among both sexes and the selected union councils but it was relatively low among children in younger age groups.

Parental acceptance of typhoid conjugate vaccine for children aged 6 months to 15 years in an outbreak setting of Lyari Town Karachi, Pakistan

BackgroundThis study aimed to evaluate the parental acceptance of Typhoid Conjugate Vaccine (TCV) and to determine the predictors of TCV vaccination status among children in an outbreak setting of extensively drug resistant (XDR) typhoid fever in Karachi, Pakistan. MethodsA cross-sectional survey using the WHO recommended rapid vaccine coverage assessment technique was conducted. Out of 11, four union councils (UCs) in Lyari Town were randomly selected. A parent or primary caretaker from the eligible household was interviewed. Data were collected using a locally validated vaccine attitudes scale (VAS). Sum of scores was calculated for VAS. A higher score denoted negative attitudes and perceptions regarding TCV and vice versa. Multivariable logistic regression was performed to determine the predictors of TCV vaccination status. ResultsBased on the 14-item parental VAS, 78.0 % of the parents had a score between 0 to <40 and 22 % had a score ≥40. VAS score of <40 was significantly associated with higher odds of receiving TCV during the campaign setting (adjusted Odds Ratio (aOR): 1.30; 95 % Confidence Interval (CI): 1.02, 1.66). The odds of receiving TCV vaccination were higher among children whose parents were aware of the ongoing vaccination campaign in the area (aOR: 4.57; 95 % CI: 2.93, 7.12) and expressed willingness to get their child vaccinated against typhoid fever (aOR: 2.54; 95 % CI: 1.82, 3.55). ConclusionParental awareness of the ongoing vaccination campaign, positive perception and attitudes towards vaccine were found to be significantly associated with TCV vaccination among children. Appropriately structured pre-vaccination awareness campaigns focused on childhood vaccination targeted towards parents are necessary to improve parental awareness, attitude and behavior towards vaccination.

PanTop: Pandemic Topic Detection and Monitoring System (Student Abstract)

Diverse efforts to combat the COVID-19 pandemic have continued throughout the past two years. Governments have announced plans for unprecedentedly rapid vaccine development, quarantine measures, and economic revitalization. They contribute to a more effective pandemic response by determining the precise opinions of individuals regarding these mitigation measures. In this paper, we propose a deep learning-based topic monitoring and storyline extraction system for COVID-19 that is capable of analyzing public sentiment and pandemic trends. The proposed method is able to retrieve Twitter data related to COVID-19 and conduct spatiotemporal analysis. Furthermore, a deep learning component of the system provides monitoring and modeling capabilities for topics based on advanced natural language processing models. A variety of visualization methods are applied to the project to show the distribution of each topic. Our proposed system accurately reflects how public reactions change over time along with pandemic topics.

Comparison of DNA vaccines with AddaS03 as an adjuvant and an mRNA vaccine against SARS-CoV-2

Emerging variants of SARS-CoV-2 call for frequent changes in vaccine antigens. Nucleic acid-based vaccination strategies are superior as the coding sequences can be easily altered with little impact on downstream production. mRNA vaccines, including variant-specific boosters, are approved for SARS-CoV-2. Here, we tested the efficacy of DNA vaccines against the SARS-CoV-2 Spike aided by the AS03 adjuvant using electroporation and compared their immunogenicity with an approved mRNA vaccine (mRNA-1273). DNA vaccination elicited robust humoral and cellular immune responses in C57BL/6 mice with Spike-specific antibody neutralization and T cells produced from 20 μg DNA vaccines similar to that from 0.5 μg mRNA-1273. Furthermore, a Nanoplasmid-based vector further increased the immunogenicity. Our results indicate that adjuvants are critical to the efficacy of DNA vaccines in stimulating robust immune responses against Spike, highlighting the feasibility of plasmid DNA as a rapid nucleic acid-based vaccine approach against SARS-CoV-2 and other emerging infectious diseases.

A Trim-RBD-GEM vaccine candidate protects mice from SARS-CoV-2

The SARS-CoV-2 pandemic has continued for about three years since emerging in late December 2019, resulting in millions of deaths. Therefore, there is an urgent need to develop a safe and effective vaccine to control SARS-CoV-2. In this study, we developed a bacterium-like particle vaccine that displays the SARS-CoV-2 receptor binding domain (RBD) (named Trim-RBD-GEM) using the GEM-PA system. We evaluated the immunogenicity and protective efficacy of the Trim-RBD-GEM vaccine with the oil-in-water adjuvant AddaVax in C57BL/6 N mice intramuscularly. We found that Trim-RBD-GEM&AddaVax induced high levels of humoral immunity in C57BL/6 N mice. Additionally, the lung virus loads in the immunized group were significantly decreased compared to the adjuvant control and mock groups. Therefore, this vaccine provides protection against lethal infection in a C57BL/6 N mouse model. Our Trim-RBD-GEM&AddaVax vaccine is potentially a promising, rapid, and safe subunit vaccine for preventing and controlling SARS-CoV-2.

High-Throughput SARS-CoV-2 Antiviral Testing Method Using the Celigo Image Cytometer

The COVID-19 pandemic has created a worldwide public health crisis that has since resulted in 6.8 million reported deaths. The pandemic prompted the immediate response of researchers around the world to engage in rapid vaccine development, surveillance programs, and antiviral testing, which resulted in the delivery of multiple vaccines and repurposed antiviral drug candidates. However, the emergence of new highly transmissible SARS-CoV-2 variants has renewed the desire for discovering new antiviral drug candidates with high efficacy against the emerging variants of concern. Traditional antiviral testing methods employ the plaque-reduction neutralization tests (PRNTs), plaque assays, or RT-PCR analysis, but each assay can be tedious and time-consuming, requiring 2–3 days to complete the initial antiviral assay in biologically relevant cells, and then 3–4 days to visualize and count plaques in Vero cells, or to complete cell extractions and PCR analysis. In recent years, plate-based image cytometers have demonstrated high-throughput vaccine screening methods, which can be adopted for screening potential antiviral drug candidates. In this work, we developed a high-throughput antiviral testing method employing the Celigo Image Cytometer to investigate the efficacy of antiviral drug candidates on SARS-CoV-2 infectivity using a fluorescent reporter virus and their safety by measuring the cytotoxicity effects on the healthy host cell line using fluorescent viability stains. Compared to traditional methods, the assays defined here eliminated on average 3–4 days from our standard processing time for antiviral testing. Moreover, we were able to utilize human cell lines directly that are not typically amenable to PRNT or plaque assays. The Celigo Image Cytometer can provide an efficient and robust method to rapidly identify potential antiviral drugs to effectively combat the rapidly spreading SARS-CoV-2 virus and its variants during the pandemic.

Enabling rapid vaccine development through manufacturing innovation &amp; process efficiency

Enabling rapid vaccine development through manufacturing innovation &amp; process efficiency

Evaluation of COVID-19 vaccine implementation in a large safety net health system.

To evaluate rapid COVID-19 vaccine clinic implementation from January-April 2021 in the Los Angeles County Department of Health Services (LACDHS), the second-largest US safety net health system. During initial vaccine clinic implementation, LACDHS vaccinated 59,898 outpatients, 69% of whom were Latinx (exceeding the LA County Latinx population of 46%). LACDHS is a unique safety net setting to evaluate rapid vaccine implementation due to system size, geographic breadth, language/racial/ethnic diversity, limited health staffing resources, and socioeconomic complexity of patients. Implementation factors were assessed through semi-structured interviews of staff from all twelve LACDHS vaccine clinics from August-November 2021 using the Consolidated Framework for Implementation Research (CFIR) and themes analyzed using rapid qualitative analysis. Of 40 potential participants, 25 health professionals completed an interview (27% clinical providers/medical directors, 23% pharmacist, 15% nursing staff, and 35% other). Qualitative analysis of participant interviews yielded ten narrative themes. Implementation facilitators included bidirectional communication between system leadership and clinics, multidisciplinary leadership and operations teams, expanded use of standing orders, teamwork culture, use of active and passive communication structures, and development of patient-centered engagement strategies. Barriers to implementation included vaccine scarcity, underestimation of resources needed for patient outreach, and numerous process challenges encountered. Previous studies focused on robust advance planning as a facilitator and understaffing and high staff turnover as barriers to implementation in safety net health systems. This study found facilitators that can mitigate lack of advance planning and staffing challenges present during public health emergencies such as the COVID-19 pandemic. The ten identified themes may inform future implementations in safety net health systems.

Promoting RAPID Vaccine Science Education at the Onset of the COVID-19 Pandemic.

At the onset of the 2019 coronavirus disease (COVID-19) pandemic, it was clear that we needed to support public education on the science of vaccines. This project was born of that need and led to the development of comprehensive educational materials that addressed the process of science, severe acute respiratory syndrome coronavirus 2 biology, vaccine development, and science communication and outreach. Called the "Online Vaccine Science Resources for COVID-19 Education," the materials generated were designed to be implemented by educators and community groups in various contexts. They took the form of four modules and general audience informational videos available on a YouTube channel. Each module was assembled as a toolkit with instructional videos, assessments, discussion questions, assignments, synthesis activities, and guides for constructing infographics and dual poster (science and general public audience) presentations. The materials were piloted and tested in various educational settings, including 2-year and 4-year colleges. Data gathered from surveys of faculty and student participants suggested that exposure to the materials promoted student trust in vaccination and the scientific process of vaccine development, and increased the likelihood of their getting a freely available vaccine. Assessment data indicated that the materials were successful in helping students achieve the learning objectives for the modules. Our results underscored the continued need for science education strategies that address the critical problem of vaccine hesitancy as we continue to emerge from the COVID-19 pandemic.

Immunogenicity of coronavirus disease 2019 vaccines in children: A review with ChatGPT

AbstractSARS‐CoV‐2 causes millions of infection cases and coronavirus disease 2019 (COVID‐19)‐related deaths worldwide. In addition to acute illnesses, children and adolescents suffer from post‐infectious complications. Vaccination is a promising preventative treatment that can confer protection from these devastating outcomes. Utilizing ChatGPT, this review discusses the immunogenicity of mRNA and inactivated COVID‐19 vaccines in children and adolescents. Rapid vaccine discovery during the COVID‐19 pandemic led to the approval of the mRNA vaccines that stimulate potent antibody responses in pediatric population, and the younger age groups develop higher neutralizing and non‐neutralizing antibody responses than those who are older. Natural infection induces weaker antibody responses than vaccination. Vaccine‐induced humoral immunity decreases over time, as antibodies decline six months after the second dose. However, antibody avidity increases, which partly maintains neutralization and Fc‐effector functions that provide more durable protection. Inactivated COVID‐19 vaccines generate strong antibody responses in children and adolescents. They induce T cell responses against multiple structural protein antigens, although their neutralizing antibody responses appear weaker and wane more quickly than mRNA vaccines. Full‐dose intradermal administration and heterologous prime‐boost may improve the immunogenicity of inactivated vaccines. In children and adolescents, immune protection from the pre‐Omicron variants of concern (VOCs) is maintained. Vaccination induces less antibody neutralization against the Omicron variant, but non‐neutralizing antibodies and T cell responses persist. Hybrid immunity provides stronger immunogenicity against SARS‐CoV‐2 in the pediatric population. Future research must focus on long‐term immunity, interaction with breakthrough reinfections, cross‐reactivity against new VOCs, T cell immunogenicity and immunogenicity in young children.

Superspreading, overdispersion and their implications in the SARS-CoV-2 (COVID-19) pandemic: a systematic review and meta-analysis of the literature

BackgroundA recurrent feature of infectious diseases is the observation that different individuals show different levels of secondary transmission. This inter-individual variation in transmission potential is often quantified by the dispersion parameter k. Low values of k indicate a high degree of variability and a greater probability of superspreading events. Understanding k for COVID-19 across contexts can assist policy makers prepare for future pandemics.MethodsA literature search following a systematic approach was carried out in PubMed, Embase, Web of Science, Cochrane Library, medRxiv, bioRxiv and arXiv to identify publications containing epidemiological findings on superspreading in COVID-19. Study characteristics, epidemiological data, including estimates for k and R0, and public health recommendations were extracted from relevant records.ResultsThe literature search yielded 28 peer-reviewed studies. The mean k estimates ranged from 0.04 to 2.97. Among the 28 studies, 93% reported mean k estimates lower than one, which is considered as marked heterogeneity in inter-individual transmission potential. Recommended control measures were specifically aimed at preventing superspreading events. The combination of forward and backward contact tracing, timely confirmation of cases, rapid case isolation, vaccination and preventive measures were suggested as important components to suppress superspreading.ConclusionsSuperspreading events were a major feature in the pandemic of SARS-CoV-2. On the one hand, this made outbreaks potentially more explosive but on the other hand also more responsive to public health interventions. Going forward, understanding k is critical for tailoring public health measures to high-risk groups and settings where superspreading events occur.

Unintended consequences of communicating rapid COVID-19 vaccine policy changes– a qualitative study of health policy communication in Ontario, Canada

BackgroundThe success of the COVID-19 vaccination roll-out depended on clear policy communication and guidance to promote and facilitate vaccine uptake. The rapidly evolving pandemic circumstances led to many vaccine policy amendments. The impact of changing policy on effective vaccine communication and its influence in terms of societal response to vaccine promotion are underexplored; this qualitative research addresses that gap within the extant literature.MethodsPolicy communicators and community leaders from urban and rural Ontario participated in semi-structured interviews (N = 29) to explore their experiences of COVID-19 vaccine policy communication. Thematic analysis was used to produce representative themes.ResultsAnalysis showed rapidly changing policy was a barrier to smooth communication and COVID-19 vaccine roll-out. Continual amendments had unintended consequences, stimulating confusion, disrupting community outreach efforts and interrupting vaccine implementation. Policy changes were most disruptive to logistical planning and community engagement work, including community outreach, communicating eligibility criteria, and providing translated vaccine information to diverse communities.ConclusionsVaccine policy changes that allow for prioritized access can have the unintended consequence of limiting communities’ access to information that supports decision making. Rapidly evolving circumstances require a balance between adjusting policy and maintaining simple, consistent public health messages that can readily be translated into action. Information access is a factor in health inequality that needs addressing alongside access to vaccines.

Vaccine hesitancy promotes emergence of new SARS-CoV-2 variants

The successive emergence of SARS-CoV-2 mutations has led to an unprecedented increase in COVID-19 incidence worldwide. Currently, vaccination is considered to be the best available solution to control the ongoing COVID-19 pandemic. However, public opposition to vaccination persists in many countries, which can lead to increased COVID-19 caseloads and hence greater opportunities for vaccine-evasive mutant strains to arise. To determine the extent that public opinion regarding vaccination can induce or hamper the emergence of new variants, we develop a model that couples a compartmental disease transmission framework featuring two strains of SARS-CoV-2 with game theoretical dynamics on whether or not to vaccinate. We combine semi-stochastic and deterministic simulations to explore the effect of mutation probability, perceived cost of receiving vaccines, and perceived risks of infection on the emergence and spread of mutant SARS-CoV-2 strains. We find that decreasing the perceived costs of being vaccinated and increasing the perceived risks of infection (that is, decreasing vaccine hesitation) will decrease the possibility of vaccine-resistant mutant strains becoming established by about fourfold for intermediate mutation rates. Conversely, we find increasing vaccine hesitation to cause both higher probability of mutant strains emerging and more wild-type cases after the mutant strain has appeared. We also find that once a new variant has emerged, perceived risk of being infected by the original variant plays a much larger role than perceptions of the new variant in determining future outbreak characteristics. Furthermore, we find that rapid vaccination under non-pharmaceutical interventions is a highly effective strategy for preventing new variant emergence, due to interaction effects between non-pharmaceutical interventions and public support for vaccination. Our findings indicate that policies that combine combating vaccine-related misinformation with non-pharmaceutical interventions (such as reducing social contact) will be the most effective for avoiding the establishment of harmful new variants.

A Plant-Derived Maternal Vaccine against Porcine Epidemic Diarrhea Protects Piglets through Maternally Derived Immunity.

Newborn piglets are susceptible to a highly contagious enteritis caused by the porcine epidemic diarrhea virus (PEDV), associated with high levels of mortality worldwide. There is pressing need for a rapid, safe, and cost-effective vaccine to safeguard pigs from getting infected by PEDV. PEDV belongs to the coronavirus family and is characterized by high levels of mutability. The primary goal of a PEDV vaccine is to provide immunity to newborn piglets through vaccination of sows. Plant-based vaccines are becoming more popular because they have low manufacturing costs, are easily scalable, have high thermostability, and a long shelf life. This is in contrast to conventional vaccines which include inactivated, live, and/or recombinant types that can be expensive and have limited ability to respond to rapidly mutating viruses. The binding of the virus to host cell receptors is primarily facilitated by the N-terminal subunit of the viral spike protein (S1), which also contains several epitopes that are recognized by virus-neutralizing antibodies. As a result, we generated a recombinant S1 protein using a plant-based vaccine platform. We found that the recombinant protein was highly glycosylated, comparable to the native viral antigen. Vaccination of pregnant sows at four and two weeks before farrowing led to the development of humoral immunity specific to S1 in the suckling piglets. In addition, we noted significant viral neutralization titers in both vaccinated sows and piglets. When challenged with PEDV, piglets born from vaccinated sows displayed less severe clinical symptoms and significantly lower mortality rates compared to piglets born from non-vaccinated sows.

Self-Assembled Proteinaceous Nanoparticles for Co-Delivery of Antigens and Cytosine Phosphoguanine (CpG) Adjuvants: Implications for Nanovaccines.

Nanotechnology has developed rapidly, giving rise to "nanovaccinology". In particular, protein-based nanocarriers have gained widespread attention because of their excellent biocompatibility. As the development of flexible and rapid vaccines is challenging, modular extensible nanoparticles are urgently needed. In this study, a multifunctional nanocarrier capable of delivering various biomolecules (including polysaccharides, proteins, and nucleic acids) was designed by fusing the cholera toxin B subunit with streptavidin. Then, the nanocarrier was used to prepare a bioconjugate nanovaccine against S. flexneri by co-delivery of antigens and CpG adjuvants. Subsequent experimental results indicated that the nanovaccine with multiple components could stimulate both adaptive and innate immunity. Moreover, combining nanocarriers and CpG adjuvants with glycan antigens could improve the survival of vaccinated mice during the interval of two vaccination injections. The multifunctional nanocarrier and the design strategy demonstrated in this study could be utilized in the development of many other nanovaccines against infectious diseases.