Vaccine Delivery Research Articles

Pichia pastoris-Derived β-Glucan Capsules as a Delivery System for DNA Vaccines

Background/Objectives: DNA vaccines are rapidly produced and adaptable to different pathogens, but they face considerable challenges regarding stability and delivery to the cellular target. Thus, effective delivery methods are essential for the success of these vaccines. Here, we evaluated the efficacy of capsules derived from the cell wall of the yeast Pichia pastoris as a delivery system for DNA vaccines. Methods: The capsules were extracted from the yeast Pichia pastoris strain GS115, previously grown in a YPD medium. pVAX1 expression vector was adopted to evaluate the DNA vaccine insertion and delivery. Three encapsulation protocols were tested to identify the most effective in internalizing the plasmid. The presence of plasmids inside the capsules was confirmed by fluorescence microscopy, and the encapsulation efficiency was calculated by the difference between the initial concentration of DNA used for insertion and the concentration of unencapsulated DNA contained in the supernatant. The capsules were subjected to different temperatures to evaluate their thermostability and were co-cultured with macrophages for phagocytosis analysis. HEK-293T cells were adopted to assess the cytotoxicity levels by MTT assay. Results: The microscopy results indicated that the macrophages successfully phagocytosed the capsules. Among the protocols tested for encapsulation, the one with 2% polyethylenimine for internalization showed the highest efficiency, with an encapsulation rate above 80%. However, the vaccine capsules obtained with the protocol that used 5% NaCl showed better thermal stability and encapsulation efficiency above 63% without induction of cell viability loss in HEK 293T. Conclusions: We successfully described a vaccine delivery system using yeast capsules derived from Pichia pastoris, demonstrating its potential for DNA vaccine delivery for the first time. Additional studies will be needed to characterize and improve this delivery strategy.

Nano-bio-encapsulation of phyto-vaccines: a breakthrough in targeted cancer immunotherapy.

Nano bio-encapsulation of phyto-vaccines for cancer has marked a cutting-edge strategy that brings together nanotechnology with plant-derived vaccines to enhance cancer therapy. Phyto-vaccines, isolated from bioactive compounds found in plants called protein bodies, have been shown to potentially stimulate the immune system to recognise and destroy cancer cells. However, challenges such as poor stability, rapid degradation, and limited bioavailability in the body have hindered their clinical application. Nano bio-encapsulation offers a solution by packaging these phyto-vaccines into nanoscale carriers such as lectins have provided ways to overcome these limitations. They protect the protein bodies from degradation by proteolytic enzymes, enhance targeted delivery to cancer cells, and enable controlled release. This approach not only improves the bio-distribution and potency of the vaccines but also minimizes side effects, making it a highly promising, sustainable, and efficient method for cancer immunotherapy. As research progresses, this technology has the potential to revolutionize cancer treatment by providing safer and more precise therapeutic options. This review focuses on the concept of nano bio-encapsulation of phyto-vaccines for cancer treatment. It explores how nanotechnology can enhance the stability, bioavailability, and targeted delivery of plant-derived vaccines, addressing the limitations of traditional vaccines. The review delves into the potential of this innovative strategy to advance cancer immunotherapy, providing a comprehensive overview of current research and future directions.

Human Papilloma Virus Circulating Cell-Free DNA Kinetics in Cervical Cancer Patients Undergoing Definitive Chemoradiation.

The human papillomavirus (HPV) is a significant cause of cervical cancer. We hypothesized that detecting viral cell-free HPV DNA (cfDNA) before, during, and after chemoradiation (chemoRT) could provide insights into disease extent, clinical staging, and treatment response. Sixty-six patients with locally advanced cervical cancer were enrolled between 2017 and 2023. 49 received standard-of-care (SOC) treatment and 17 participated in a clinical trial combining a therapeutic HPV vaccine (PDS0101; IMMUNOCERV). Plasma was collected at baseline, weeks 1, 3, and 5 of chemoRT, and 3-4 months after chemoRT. HPV cfDNA was quantified using droplet digital PCR targeting the HPV E6/E7 oncogenes of 13 high-risk types. MRI was performed at baseline and before brachytherapy. The median follow-up was 23 months, with recurrence-free survival (RFS) of 78.4% at 2 years. Baseline nodal disease extent correlated with HPV cfDNA levels. HPV cfDNA levels peaked in week 1 of radiation and decreased through treatment. Patients receiving the PDS0101 vaccine had a higher rate of undetectable HPV type 16 cfDNA compared to SOC. HPV cfDNA clearance correlated with better 2-yr RFS (92.9% vs. 30%, log-rank p=0.0067). The strongest predictor of RFS was HPV cfDNA clearance in follow-up achieving a concordance index (CI) 0.83, which improved when combined with MRI response (CI 0.88). HPV cfDNA levels change dynamically during chemoRT. HPV cfDNA at follow-up predicts RFS. Delivery of therapeutic HPV vaccine with chemoRT was linked to rapid HPV cfDNA decline. Monitoring HPV cfDNA during and after chemoRT may guide tailoring of personalized treatment.

Is Lactococcus lactis a Suitable Candidate for Use as a Vaccine Delivery System Against Helicobacter pylori?

Helicobacter pylori was described in 1979. This bacterium, which thrives in the harsh conditions of the stomach, is typically acquired during childhood and can remain colonized for life. Approximately, 90% of the global population is affected, and H. pylori is linked to various conditions, including gastritis, peptic ulcers, lymphoproliferative gastric lymphoma, and even gastric cancer. Currently, antibiotics are the primary treatment method, but the associated challenges of antibiotic use have led to the consideration of oral vaccination as a viable preventive measure against this infection. However, the stomach's harsh environment characterized by its acidic conditions and numerous proteolytic enzymes poses significant obstacles to the development and effectiveness of oral vaccines. To address these challenges, researchers have proposed and evaluated several delivery systems. One of the most promising options is the use of probiotics. Among the various probiotics, Lactococcus lactis stands out as a suitable candidate for oral vaccine delivery against H. pylori due to the advancements in genetic engineering that have been applied to it. This review article discusses the limitations of current treatment strategies and rationalizes the shift toward vaccination, particularly oral vaccination for this infection. It also explores the advantages and challenges of using probiotic bacteria, with a focus on L. lactis as a delivery system. Ultimately, despite the existing challenges, L. lactis continues to be recognized as a promising delivery system. Nonetheless, further research is essential to fully assess its effectiveness and address the challenges associated with this approach.

Enablers to high vaccination uptake among a disadvantaged minority population: a qualitative study of the Arab population of Israel

BackgroundOver 1.9 million Arabs live in Israel and constitute 21% of the total population. Despite being a disadvantaged minority population with wide gaps in health indicators, Arabs have higher Human Papillomavirus (HPV) and Measles, Mumps, and Rubella (MMR) vaccination rates compared with the general Jewish population.MethodsIn-depth interviews with 21 health care providers, 16 Arab mothers, and 16 teenagers were conducted to collect information about health system enablers to HPV and MMR vaccination. All interviews were conducted in Arabic by an Arab researcher, audio-recorded, transcribed, and analysed using thematic analysis of the transcripts. Themes were mapped according to the WHO Health Systems Building Block Framework.ResultsWe identified several health system enablers. On the service delivery level, accessible and availability of vaccination services, delivery of vaccines through the school system and mother child clinics, and framing vaccinations as the norm were themes. Personable characteristics of the health workforce, the health care providers belonging to the same cultural group, and high levels of trust towards healthcare professionals were reported. Vaccination provided at no cost was also identified. On the leadership/governance level, the Arab community felt equal treatment and distribution of services, which was also an enabler reported. Despite high vaccine uptakes, parents and teenagers had limited knowledge regarding vaccination, particularly HPV.ConclusionsThis study highlights that a combination of good access and delivery to vaccination, delivered by a culturally competent, available, accessible respectful workforce can enable disadvantaged minorities to achieve high vaccine coverage, in particular in a cultural context where the population trusts and follows medical advice. Such evidence can serve as a basis for developing policies, interventions, and guidance to improve vaccine uptake among other underserved minority communities.

Extracellular vesicles powered cancer immunotherapy: Targeted delivery of adenovirus-based cancer vaccine in humanized melanoma model.

Malignant melanoma, a rapidly spreading form of skin cancer, is becoming more prevalent worldwide. While surgery is successful in treating early-stage melanoma, patients with advanced disease have only a 20% chance of surviving beyond five years. Melanomas with mutations in the NRAS gene are characterized for a more aggressive tumor biology, poorer prognosis and shorter survival. Hence, new therapeutic strategies are needed, especially for this specific group of patients. Novel approaches, such as cancer vaccines, offer promising solutions by stimulating the anti-tumor immune response. Nevertheless, their clinical efficacy is still modest and more effective approaches are required. Herein, we propose the systemic administration of the adenovirus-based cancer vaccine complexed in extracellular vesicles (EVs) with the aim of achieving a targeted therapeutic effect. The vaccine was based on previously tested oncolytic adenovirus Ad5/3-D24-ICOSL-CD40L in combination with melanoma-specific antigens targeting NRAS mutations to enhance the anticancer effect. The antineoplastic properties of the oncolytic vaccine were evaluated in xenograft MUG Mel-2 melanoma BALB/c nude mice. Moreover, to mimic the tumor microenvironment, while investigating at the same time immune cell infiltration and drug penetration, we established a 3D co-culture model based on human NRAS mutated MUG Mel-2 spheroids and PBMCs (HLA matched), which displayed a synergistic effect when treated with the cancer vaccine compared to relative controls. Subsequently, we investigated the systemic delivery of the vaccine in EV formulations in a humanized NSG MUG Mel-2 melanoma mouse model. Our study provides a promising strategy for a tumor-targeted vaccine delivery by EVs, resulting in improved anticancer efficacy and increased infiltration of tumor-infiltrating lymphocytes. This study explores the potential of EVs for the selective delivery of cancer vaccines against malignancies, such as NRAS melanoma. Overall, this research could pave the way for applying autologous EVs as a safe and efficacious tool for targeted cancer therapy.

Advances in the study of LNPs for mRNA delivery and clinical applications.

Messenger ribonucleic acid (mRNA) was discovered in 1961 as an intermediary for transferring genetic information from DNA to ribosomes for protein synthesis. The COVID-19 pandemic brought worldwide attention to mRNA vaccines. The emergency use authorization of two COVID-19 mRNA vaccines, BNT162b2 and mRNA-1273, were major achievements in the history of vaccine development. Lipid nanoparticles (LNPs), one of the most superior non-viral delivery vectors available, have made many exciting advances in clinical translation as part of the COVID-19 vaccine and therefore has the potential to accelerate the clinical translation of many gene drugs. In addition, due to these small size, biocompatibility and excellent biodegradability, LNPs can efficiently deliver nucleic acids into cells, which is particularly important for current mRNA therapeutic regimens. LNPs are composed cationic or pH-dependent ionizable lipid bilayer, polyethylene glycol (PEG), phospholipids, and cholesterol, represents an advanced system for the delivery of mRNA vaccines. Furthermore, optimization of these four components constituting the LNPs have demonstrated enhanced vaccine efficacy and diminished adverse effects. The incorporation of biodegradable lipids enhance the biocompatibility of LNPs, thereby improving its potential as an efficacious therapeutic approach for a wide range of challenging and intricate diseases, encompassing infectious diseases, liver disorders, cancer, cardiovascular diseases, cerebrovascular conditions, among others. Consequently, this review aims to furnish the scientific community with the most up-to-date information regarding mRNA vaccines and LNP delivery systems.

Role of route of delivery on Chlamydia abortus vaccine-induced immune responses and genital tract immunity in mice.

We investigated if the efficacy of a Chlamydia abortus (Cab) subunit vaccine is influenced by route of administration. Thus, female CBA/J mice were immunized either by mucosal or systemic routes with Vibrio cholerae ghost (VCG)-based vaccine expressing T and B cell epitopes of Cab polymorphic membrane protein (Pmp) 18D, termed rVCG-Pmp18.3. Vaccine evaluation revealed that all routes of vaccine delivery induced a Th1-type antibody response after a prime boost or three-dose immunization regimen. Also, the intranasal and rectal mucosal and intramuscular systemic routes induced cross-reactive neutralizing antibodies against homologous and heterologous Cab strains. Irrespective of the route of immunization, the vaccine elicited a Th1-type cytokine response (IFN-γ/IL-4 >1) in immunized mice. Analysis of reduction in genital Cab burden as an index of protection showed that immunization induced substantial degrees of protection against infection, irrespective of route of delivery with the intranasal and rectal mucosal routes showing superior levels of protection 12 days postchallenge. Furthermore, there was correlation between the humoral and cellular immune response and protection was associated with the Cab-specific serum IgG antibody avidity and IFN-γ. Thus, while route of administration impacts vaccine efficacy, the rVCG-Pmp18.3-induced protective immunity against Cab respiratory infection can be accomplished by both mucosal and systemic immunization.

Chitosan-coated PLA/poloxamer nanoparticles stimulate immunologic cancer cell death and synergistic chemo-immunotherapeutic efficacy

Cancer, a key factor in declining global life expectancy, has driven the integration of chemotherapy and immunotherapy to address multidrug resistance and influence the tumor microenvironment. We developed a novel vaccine delivery carrier, a chitosan-coated polylactic acid/poloxamer nanoparticle (CPP NP), designed to co-encapsulate an anticancer drug and antigen without any chemical conjugation process, enabling effective and synergistic cancer chemo-immunotherapy. The CPP NP achieved synergistic efficacy through paclitaxel (PTX), an immunogenic cell death-inducing chemotherapeutic agent; ovalbumin (OVA), which promotes dendritic cell maturation; and enhanced cellular uptake facilitated by chitosan. The PTX and OVA-loaded CPP NPs (PTX/OVA@CPP NPs) were stable in PBS for four weeks and resuspended well after lyophilization without any cryoprotectants. Moreover, PTX and OVA from the NPs exhibited a sustained release rate and pH-responsive release pattern within different cellular microenvironments. Importantly, PTX@CPP NPs exhibited much higher anticancer efficacy across various cancer cell lines, even multidrug-resistant cells, compared to free PTX and PTX@PP NPs without the chitosan coating. In antigen-presenting cells, OVA@CPP NPs led to higher IL-2 secretion and cellular uptake compared to free OVA and OVA@PP NPs. Furthermore, in a tumor-bearing mouse model, PTX/OVA@CPP NPs exhibited strong synergistic tumor suppression and triggered OVA antigen-specific responses, promoting an antitumor immune response. These findings demonstrate that PTX/OVA@CPP NPs show potential as new chemo-immunotherapeutic agents for effective cancer treatment.

The design of manufacturing process of mold for producing polymeric dissolving microneedles

Introduction. Polymeric dissolving microneedles are promising way for drug delivery especially for vaccine delivery. It is an important task to create a scalable way of manufacture of dissolving polymeric microneedles. First step in this process is to create an easy and cheap way of producing negative master-molds for microneedles. Objective. To develop the laser production technology of negative master-mold for dissolving polymeric microneedles. Material and methods. Possibility of using different polymer plates (polydimethylsiloxane, polycarbonate, polystyrene, polypropylene, polymethyl methacrylate and polyethylene terephthalate) for producing negative microneedle molds and material’s surface free energy were examined. The modes of laser ablation of polymer and ways of its control were investigated. Pullulan dissolving microneedles were produced by using designed molds and examined by optical microscopy. Results. Polyethylene terephthalate was chosen as the optimal polymer for producing negative microneedle mold because it leads to producing symmetrical microneedles with desired geometry. Also the 2-step laser technology for the fabrication of polymeric microneedle molds and methods of mold’s quality control during manufacture was designed in this study. The technological scheme of polyethylene terephthalate microneedle mold’s manufacture was proposed in results of this study. The variety of manufacturing defects of polyethylene terephthalate microneedle mold and it’s causes were summarized. Conclusion. The designed laser technology of producing negative microneedle molds in combination with right mold’s material (polyethylene terephthalate) can guarantee robust producing of dissolving polymeric microneedles and gives a possibility to scale it up.

Personalized Membrane Protein Vaccine Based on a Lipid Nanoparticle Delivery System Prevents Postoperative Recurrence in Colorectal Cancer Models

While accessing tumor neoantigens and developing effective delivery systems have posed significant challenges in therapeutic oncology vaccines, this study introduces a cost- and time-efficient personalized tumor vaccine demonstrating potent anti-tumor effects in a mouse xenograft model. This vaccine utilizes a lipid nanoparticle (C5 LNP) system loaded with membrane protein antigens (mAg) derived from surgically excised tumor tissue. Its safety and efficacy were validated in a B16-OVA murine model. C5/OVA exhibited significant uptake by dendritic cells (DCs), leading to cross-presentation, maturation, and subsequent initiation of robust cell-mediated and humoral immune responses. This resulted in clear tumor growth suppression and extended survival in the B16-OVA model. Furthermore, the personalized C5/mAg vaccine effectively inhibited tumor growth in a colorectal carcinoma model. When combined with anti-PD-1 therapy, it notably increased complete remission (CR) rates in the CT26 xenograft model. Vaccinated mice demonstrated 100% resistance to tumor rechallenge, underscoring the vaccine's ability to induce long-term immune memory. This study presents a promising personalized cancer vaccine delivery system with potential for both treatment and prevention of carcinoma in clinical applications. Statement of significanceIn this paper, we present a scheme for manufacturing personalized tumor vaccines. The vaccine component consists of lipid nanoparticles (LNPs) designated C5 and membrane protein antigens (mAg) derived from autologous tumor tissue surgically resected from the patient. Our study demonstrates that the personalized mAg-C5 vaccine for colorectal carcinoma significantly inhibits tumor growth. Furthermore, conjugation with anti-PD-1 therapy demonstrably increased the complete remission (CR) rate in the murine CT26 xenograft tumor model. Additionally, mice treated with the C5/mAg vaccine exhibited 100% resistance to tumor growth in a colon carcinoma rechallenge model, indicating the induction of immune memory by the vaccine.Our research results suggest that the mAg-LNP vaccine is a simple, cost-effective treatment that clinicians can easily and quickly integrate into routine practice.

Queuing Theory-Based Model for Optimization of Covid-19 Vaccination and Booster Delivery

Although queuing theory is commonly utilized in businesses to analyze and model processes involving waiting lines, the healthcare sector sees a difference from other industries when it comes to optimizing fixed resources under alterable demand conditions. To enhance operational effectiveness and cut down on waiting times, hospital operation managers need to be informed on the state of business processes. A scientific method to reduce systemic inefficiencies and raise patient satisfaction is the queuing theory. The objective of this study is to use queuing theory to optimize COVID-19 vaccination and booster delivery. This study discussed two distinct models, one for bigger MV hubs and the other for smaller GP vaccination clinics. The current study demonstrated how these models may be used to anticipate staffing needs to prevent bottlenecks, predict daily throughput given staff capacity limits, and simulate the queuing process. With respectable face validity, we produced accurate estimates of the distributions of given service times and overall processing times. In the future, this may be improved by carrying out a time-use survey to get empirical data on total processing time, which could be compared to the projected processing time of the model and service times for each station, which would help guide the model's inputs.

Evaluation of Integrated Child Health Days as a Catch-Up Strategy for Immunization in Three Districts in Uganda

Background: Uganda’s Integrated Child Health Day (ICHD) initiative aims to improve children’s access to vaccinations. Although widely used as a catch-up vaccination strategy, the effectiveness of the ICHD program in increasing immunization coverage, especially among vulnerable populations, has not been recently evaluated. This study assessed the reach and uptake of ICHD for immunizations in Uganda. Methods: A mixed-methods evaluation was conducted in three districts (Rakai, Kayunga, and Bukedea) where ICHDs occurred. The data collection included a cross-sectional household survey using validated WHO-adapted questionnaires of 1432 caregivers of children under five years old, key informant interviews with 42 health managers and workers, and nine focus group discussions with caregivers between October and December 2022. The vaccines assessed were Bacillus Calmette–Guerin, oral polio, Pentavalent, pneumococcal conjugate, rotavirus (RV), and measles-rubella (MR). Results: The immunization coverage based on child health cards was over 90% for all vaccines except for the second dose of RV (88.3%) and MR (16.2%). Among the children, 2.3% had received no Pentavalent vaccine, and 69.4% were fully vaccinated for their age. Of the 631 children who attended ICHDs, 79.4% received at least one vaccine during the event. Village Health Teams (49%), health workers (18.3%), and megaphone outreach (17.9%) were the primary information sources. Key informants cited challenges with coordination, vaccine delivery, and mobilization. Conclusions: Despite operational challenges, ICHDs appear to have contributed to routine childhood vaccinations. Further research is needed to assess the sustainability and cost-effectiveness of the program.

Barriers and Facilitators to Vaccine Equity Amidst the COVID-19 Vaccine Rollout in the United States

State and local health departments were responsible for ensuring equitable distribution of the COVID-19 vaccine. This qualitative study aimed to identify the challenges, strategies, disappointments, and successes in achieving equity for hard-to-reach and at-risk populations. Using a purposive sampling strategy, 16 individuals affiliated with health departments across nine states, each holding leadership roles in vaccine distribution, were interviewed between late 2021 and mid-2022. The key factors promoting vaccine equity included (1) inviting community members to serve on vaccine advisory groups to participate in decision-making; (2) utilizing pre-existing community relationships and spaces to facilitate the planning and distribution of the vaccine; and (3) establishing and building upon community outreach to support accessibility and uptake of the vaccine. The barriers included (1) a lack of clarity on vaccine prioritization criteria; (2) language/communication access; and (3) the initial focus on mass vaccination sites for vaccine delivery. The stakeholders also highlighted potential facilitators for increasing equity in future vaccine rollouts. Overall, community engagement emerged as a critical factor in ensuring equity during disaster response efforts.

Intranasal delivery of a subunit protein vaccine provides protective immunity against JN.1 and XBB-lineage variants.

The mucosal immune response plays a crucial role in the prevention of respiratory viruses. Given the risk of recurrent SARS-CoV-2 infections in the population, the rapid development of next-generation intranasal COVID-19 vaccines with high safety and efficacy is paramount. In the current study, we developed a protein-based intranasal vaccine comprising the XBB.1.5 receptor binding domain (RBD)-derived trimeric recombinant protein (RBDXBB.1.5-HR) and an MF59-like oil-in-water adjuvant. Intranasal administration of RBDXBB.1.5-HR vaccine elicited robust and sustained humoral immune responses in mice and rats, resulting in high levels of neutralizing antibodies against XBB-lineage subvariants, with protection lasting for at least six months. The intranasal RBDXBB.1.5-HR vaccine generated potent mucosal immune responses, characterized by the inductions of tissue-resident T (TRM) cells, local cellular immunity, germinal center, and memory B cell responses in the respiratory tract. The combination of intramuscular and intranasal delivery of the RBDXBB.1.5-HR vaccine demonstrated exceptional systemic and mucosal protective immunity. Furthermore, intranasal delivery of RBDXBB.1.5-HR vaccine as a heterologous booster shot showed more effective boosting effects after mRNA administration compared to homologous vaccination, as evidenced by the induction of superior systemic and extra mucosal immune response. Importantly, the intranasal RBDXBB.1.5-HR vaccine conferred efficient protection against the challenge with authentic EG.5.1 viruses in vivo. These findings identify the intranasal RBDXBB.1.5-HR vaccine as a potential mucosal vaccine candidate for the prevention of SARS-CoV-2 infection.

Transdermal delivery of PeptiCRAd cancer vaccine using microneedle patches

Microneedles (MNs) are a prospective system in cancer immunotherapy to overcome barriers regarding proper antigen delivery and presentation. This study aims at identifying the potential of MNs for the delivery of Peptide-coated Conditionally Replicating Adenoviruses (PeptiCRAd), whereby peptides enhance the immunogenic properties of adenoviruses presenting tumor associated antigens. The combination of PeptiCRAd with MNs containing polyvinylpyrrolidone and sucrose was tested for the preservation of structure, induction of immune response, and tumor eradication. The findings indicated that MN-delivered PeptiCRAd was effective in peptide presentation in vivo, leading to complete tumor rejection when mice were pre-vaccinated. A rise in the cDC1 population in the lymph nodes of the MN treated mice led to an increase in the effector memory T cells in the body. Thus, the results of this study demonstrate that the combination of MN technology with PeptiCRAd may provide a safer, more tolerable, and efficient approach to cancer immunotherapy, potentially translatable to other therapeutic applications.

Enhancing Vaccine Efficacy and Accessibility through Microneedle Technology: A Review

Microneedling, a minimally invasive technique involving the creation of microchannels in the skin, has emerged as a promising platform for vaccine delivery. The use of microneedles for vaccination represents a new era in immunization techniques, wherein patients no longer dread sharp pricks. Their breakthrough potential lies in their ability to deliver vaccines directly into the epidermis or dermis where a high density of immune cells improve the particularly relevant effects of vaccines. Their intro- duction has met various challenges often experienced with traditional methods like bites caused by fear, pain from needles, or even that any medical doctor may take a long to administer them. Microneedles could improve stability and lessen the dependence on cold chain transport systems since they can be prepared in dry form. In addition to providing an al- ternative to syringes, they are also considered less painful than them. The review highlights the potential of mi- croneedles to improve vaccination rates, especially in un- derserved populations, and identifies key areas for future research and development.

Evaluation of Vaccination Coverage Against COVID-19 Among Postpartum Women at the Gaspard Kamara Health Center in Senegal in 2020

The COVID-19 pandemic has shaken the world and the rapid delivery of vaccines against the virus has raised many questions. Doubts have been raised about the effectiveness and safety of the vaccine in pregnant and breastfeeding women, hence the need to assess vaccination coverage of postpartum women at the Gaspard Kamara health center. We therefore carried out a cross-sectional analytical study from May 31 to June 28, 2022 on all women who gave birth at the Gaspard Kamara health center. Exhaustive recruitment was carried out and the data were analyzed using the SSP software version 2022. In total, 235 women participated in the study, with a mean age of 28.22 ± 5.96 years and extremes 16 and 44 years old. More than half of the patients (68.94%) had given birth vaginally. Those with secondary education accounted for 72.34%. Less than a quarter of women (7.23%) tested positive for COVID19 and 96.60% of them received information on the fight against COVID19, with the media being their main source of information. Less than half (40.43%) knew the vaccines available in Senegal, Johnson & Johnson being the best known. The majority of women (82.55%) believe in the effectiveness of vaccination to eradicate the disease. Age (30 years), lack of information on the fight against COVID19, lack of knowledge of the risks of serious forms in FE, knowledge of the availability of the vaccine in Senegal and vaccination of the spouse were statistically associated with vaccination against COVID19 among women in this country. study. Conclusion: The results of this study show the need to strengthen awareness and communication on the effectiveness and safety of vaccines among pregnant women, particularly those under 30 years of age. Let women know that they can be vaccinated at any age and during any trimester of pregnancy and breastfeeding.

Nurses' Characteristics Associated with Good Knowledge, Attitude, and Practices (KAP) of the Malaria Vaccine in Bungoma County, Kenya.

The study examined nurse characteristics associated with Knowledge, Attitudes, and Practices (KAP) regarding malaria vaccination in Bungoma County, Kenya. Malaria remains a major health burden in Kenya, with 3.4 million cases and 12,000 deaths in 2021. Bungoma County, a malaria-endemic area, implemented the RTS S1 malaria vaccine, but dropout rates for subsequent doses are high. The fourth dose dropout, particularly in Bungoma and Siaya, poses a significant challenge to vaccine adherence. A cross-sectional descriptive study comprising mixed research methods; comprising key informant interviews was conducted among nurses in Bungoma County. A stratified random sampling was used to select 63 health facilities providing malaria vaccine. Data collection involved structured questionnaires, observation checklist, and key informant interview guide. Hawthorne effect was minimized by rapport building or familiarizing the participants by spending a whole morning at the facility CWC and assuring sampled participants of anonymity, this made the participants calm and can provide immunization services without fear of being judged. Data was analyzed through descriptive and inferential statistics to determine associations between nurse demographics and KAP scores. The study found good KAP was significantly associated with characteristics such as age, years of experience, education level, and prior malaria vaccine training. Nurses aged over 35, with higher education, and those trained in malaria vaccine administration had a higher likelihood of exhibiting good knowledge and positive attitudes. The study concludes that implementing targeted training programs and mentorship initiatives for less experienced and younger nursing staff is essential for strengthening vaccine implementation effectiveness. Enhanced continuous education programs in Bungoma County would likely improve malaria vaccine practices and outcomes. Additionally, the findings indicate that structured support systems and ongoing professional development are crucial elements in maintaining high standards of vaccine delivery. The study recommends that mandatory comprehensive training programs should be established, incorporating both theoretical knowledge and hands-on practical skills development. These programs should be regularly updated to reflect current best practices and emerging challenges in vaccine delivery. Furthermore, the implementation of structured on-site mentorship programs, combined with continuous supervision, should be prioritized to ensure consistent application of proper vaccination protocols. Regular refresher courses should be offered to maintain and update healthcare workers' knowledge and skills, while a peer support system should be established to facilitate knowledge sharing and professional development.

New Development of Vaccine Technology in Tumor Therapy

Abstract. Cancer vaccines are a crucial component of tumors immunotherapy, offering the advantage of minimizing adverse reactions to induce tumor regression. They also enable the establishment of lasting anti-tumor memory. Recent years have seen significant breakthroughs in cancer vaccines, including the customization of personalized vaccines and the transition from passive immunization to active treatment. Currently, most cancer vaccine future goals focus on improving cost and efficiency such as combining immunology and bioinformatics to predict more accurate vaccine epitopes. This paper focuses on three innovative technologies in therapeutic cancer vaccines: cell vaccine, peptide cancer vaccine and nucleic acid cancer vaccine. This paper summarizes new selection of antigen-presenting cells for autologous tumor cell vaccine and allogeneic tumor cell vaccine, new research on adjuvants of peptide cancer vaccines and new nucleic acid cancer vaccine delivery platform. In addition, the combination of therapeutic vaccines is briefly discussed. These new technologies offer cancer patients new treatment options and hope.