Vaccine: X最新文献

Scorpion envenoming (SE) is a public health problem in developing countries. In Algeria, the population exposed to the risk of SE was estimated at 86.45% in 2019. Thus, the development of a vaccine to protect the exposed population against scorpion toxins would be a major advance in the fight against this disease.

This work aimed to evaluate the immunoprotective effect of a Multiple Antigenic Peptide against the Aah II toxin of Androctonus australis hector scorpion, the most dangerous scorpion species in Algeria. The immunogen MAP1Aah2 was designed and tested accordingly. This molecule contains a B epitope, derived from Aah II toxin, linked by a spacer to a universal T epitope, derived from the tetanus toxin.

The results showed that MAP1Aah2 was non-toxic despite the fact that its sequence was derived from Aah II toxin. The immunoenzymatic assay revealed that the 3 immunization regimens tested generated specific anti-MAP1Aah2 antibodies and cross-reacted with the toxin. Mice immunized with this immunogen were partially protected against mortality caused by challenge doses of 2 and 3 LD₅₀ of the toxin. The survival rate and developed symptoms varied depending on the adjuvant and the challenge dose used. In the in vitro neutralization test, the immune sera of mice having received the immunogen with incomplete Freund’s adjuvant neutralized a challenge dose of 2 LD50.

Hence, the concept of using peptide dendrimers, based on linear epitopes of scorpion toxins, as immunogens against the parent toxin was established. However, the protective properties of the tested immunogen require further optimizations.

Since the first use of vaccine tell the last COVID-19 pandemic caused by spread of SARS-CoV-2 worldwide, the use of advanced biotechnological techniques has accelerated the development of different types and methods for immunization. The last pandemic showed that the nucleic acid-based vaccine, especially mRNA, has an advantage in terms of development time; however, it showed a very critical drawback namely, the higher costs when compared to other strategies, and its inability to protect against new variants. This showed the need of more improvement to reach a better delivery and efficacy. In this review we will describe different vaccine delivery systems including, the most used viral vector, and also variable strategies for delivering of nucleic acid-based vaccines especially lipid-based nanoparticles formulation, polymersomes, electroporation and also the new powerful tools for the delivery of mRNA, which is based on the use of cell-penetrating peptides (CPPs). Additionally, we will also discuss the main challenges associated with each system. Finlay, the efficacy and safety of the vaccines depends not only on the formulations and delivery systems, but also the dosage and route of administration are also important players, therefore we will see the different routes for the vaccine administration including traditionally routes (intramuscular, Transdermal, subcutaneous), oral inhalation or via nasal mucosa, and will describe the advantages and disadvantage of each administration route.

The 24th Annual General Meeting of the Developing Countries Vaccine Manufacturers’ Network (DCVMN), held in Cape Town, South Africa and co-hosted by Biovac, convened over 400 delegates and featured more than 100 distinguished speakers across three days. This gathering served as a vital platform for vaccine manufacturers from developing nations to share insights, challenges, and achievements, underscoring their pivotal role in global vaccine research, development, and distribution to promote vaccine equity. The conference theme centered on partnerships in various forms and their instrumental role in assisting local manufacturers in achieving their and global health objectives. Speakers provided comprehensive reviews of the vaccine industry’s current landscape, covering aspects such as development, manufacturing, quality control, technology transfer, and gender-related immunization, with a focus on the perspectives of DCVMs. This paper focuses on these interconnected areas, examining their present status through the perspectives of our member manufacturers and prominent global health organizations.

Background and aims

The Rotavirus vaccine (RVV) introduction is a landmark event in the history of Indian public health as for the first time a novel, low-cost indigenous vaccine was introduced in a short timeline between 2016 and 2019. As per WHO mandate, post-introduction evaluation (PIE) be conducted within 6 to 12 months of vaccine introduction to provide an understanding of the operational aspects of the program. For RVV PIE, an innovative approach to developing and deploying a digitized tool was employed. The present study aims to document the processes followed for digitizing the data collection and analysis tools.

Methods

The development of the RVV-PIE digital tool was undertaken in two phases. In the first phase, conceptualization and iteration of the modified WHO PIE tool were undertaken. Questions were organized sequentially to ensure natural progression in responses. The finalized questionnaire was converted to a digital version and extensive dummy data was entered to improve automated qualitative data analysis. Phase 2 involved updating the draft tool and incorporating changes to provide a field-tested version for deployment.

Results

The digital version of the tool was successfully developed. The GPS functionality of the tool allowed live tracking of data collection making the process more accountable. The tool was prepopulated with reference materials and data points for easy reference and retrieval by the evaluators. The digitization of the tool also allowed easy visualization of data through maps, charts, and graphs on a real-time user-friendly dashboard.

Conclusions

The digitization of the PIE tool for RVV in India has been a great learning experience where the dire situation of an ongoing pandemic catapulted us towards a more efficient and comprehensive process innovation. The RVV PIE tool could serve as a customizable digital PIE tool for other health programs heralding an era of a more effective and proficient process of PIE.

Background

Comirnaty, Pfizer-BioNTech's polyethylene-glycol (PEG)-containing Covid-19 vaccine, can cause hypersensitivity reactions (HSRs), or rarely, life-threatening anaphylaxis in a small fraction of immunized people. A causal role of anti-PEG antibodies (Abs) has been proposed, but causality has not yet proven in an animal model. The aim of this study was to provide such evidence using pigs immunized against PEG, which displayed very high levels of anti-PEG antibodies (Abs). We also aimed to find evidence for a role of complement activation and thromboxane A2 release in blood to explore the mechanism of anaphylaxis.

Methods

Pigs (n = 6) were immunized with 0.1 mg/kg PEGylated liposome (Doxebo) i.v., and the rise of anti-PEG IgG and IgM were measured in serial blood samples with ELISA. After ∼2–3 weeks the animals were injected i.v. with 1/3 human dose of the PEGylated mRNA vaccine, Comirnaty, and the hemodynamic (PAP, SAP) cardiopulmonary (HR, EtCO2,), hematological (WBC, granulocyte, lymphocyte and platelet counts) parameters and blood immune mediators (anti-PEG IgM and IgG antibodies, thromboxane B2, C3a) were measured as endpoints of HSRs (anaphylaxis).

Results

The level of anti-PEG IgM and IgG rose 5–10-thousand-fold in all of 6 pigs immunized with Doxebo by day 6, after which time all animals developed anaphylactic shock to i.v. injection of 1/3 human dose of Comirnaty. The reaction, starting within 1 min involved maximal pulmonary hypertension and decreased systemic pulse pressure amplitude, tachycardia, granulo- and thrombocytopenia, and skin reactions (flushing or rash). These physiological changes or their absence were paralleled by C3a and TXB2 rises in blood.

Conclusions

Consistent with previous studies, these data show a causal role of anti-PEG Abs in the anaphylaxis to Comirnaty, which involves complement activation, and, hence, it represents C activation-related pseudo-anaphylaxis. The setup provides the first large-animal model for mRNA-vaccine-induced anaphylaxis in humans.

Background

In initial COVID-19 clinical trials, menstrual health was not formally monitored, yet anecdotal reports of menstruation changes surfaced on social media. This study aims to assess the association between COVID-19 vaccines and menstruation using Clue, a period-tracking application.

Study design

A survey assessing demographics, menstrual health, stress levels, and COVID-19 vaccination was sent to Clue users between 12/7/2021 and 2/9/2022. Inclusion criteria were (1) 18 years or older (2) currently menstruating (3) not pregnant or breastfeeding since 1/2020. Menstrual data was collected for each participant. Users with cycle lengths more than 90 days were excluded. Cycle lengths were calculated for the 6-month average pre-vaccination (PRIOR), the cycle during which vaccination was administered (DURING), the cycle following DURING (AFTER1), and the cycle following AFTER1 (AFTER2). For periods, individuals were stratified based on whether vaccination was received during their menstrual period (DURING). Period lengths were additionally calculated for the 6-month average pre-vaccination (PRIOR), the first period following vaccination (AFTER1), and the period following AFTER1 (AFTER2). For unvaccinated participants, an index date (4/1/2022) was used to similarly designate menstrual cycles and periods. For each participant, cycle length changes for DURING, AFTER1, and AFTER2 compared to PRIOR were determined. Student’s t-test compared the mean of these changes between vaccinated and unvaccinated groups.

Results

Of 7,559 participants, 6,897 (91 %) were vaccinated. Compared to PRIOR, individuals vaccinated during their menstrual period demonstrated a statistically significant increase in the DURING period length, but not AFTER1 (p = 0.463) and AFTER2 (p = 0.692). No statistically significant changes were observed in period lengths of those vaccinated in between periods or in cycle lengths overall.

Conclusion

A small but statistically significant change in period length was observed only in individuals vaccinated for COVID-19 during their menstrual period. Providers can better counsel menstruating individuals to reduce vaccine misinformation.

Introduction

Blood donors world-wide were indispensable for monitoring anti-SARS-CoV-2 antibodies generated by infection and vaccination during the pandemic. Prior to the pandemic, donor vaccination behaviours were under-studied. We aimed to compare the percentage of Canadian blood donors with SARS-CoV-2 vaccination antibodies with the percentage of the general population who received at least one dose of vaccine each month during initial vaccine deployment. We also report donor attitudes towards SARS-CoV-2 vaccination.

Methods

Canadian blood donors were randomly selected for SARS-CoV-2 antibody testing over 2021 (N = 165,240). The percentage of donor samples with vaccination antibodies were compared with the percentage of general population who received at least one dose of vaccine in each month of 2021 except February. A random sample of Canadian blood donors were surveyed about vaccination intent and attitudes (N = 4,558 participated, 30.4 % response rate).

Results

The percentages of the general population vaccinated and donors with vaccination antibodies increased from 1 % to over 90 %. General population vaccination was greater early in vaccine deployment than donors (p < 0.05), greater in donors than the general population by mid-2021 (p < 0.05) but they were similar by the end of 2021. While 52.6 % of surveyed donors had received vaccine in May 2021, a further 41.1 % intended to when eligible. Most donors thought COVID-19 infection could be serious (83.5 %) and that it was important to be vaccinated even if previously infected (77.8 %).

Conclusion

Early pandemic vaccine prioritization to at-risk individuals and healthcare workers gave rise to higher general population vaccination percentages, while donors had higher vaccine antibody percentages as vaccine was deployed to progressively younger age groups. Since blood donors may be more willing to receive vaccination, under pandemic conditions they may be valuable for monitoring vaccination-induced seroprevalence.

Background

Shigellosis is one of the significant causes of diarrhea in Bangladesh. It is a global health problem; approximately 1.3 million people die yearly from Shigellosis. The current treatment method, using different antibiotics against Shigellosis is ineffective. Moreover, it becomes a worrying situation due to the emergence of antibiotic-resistant pathogenic microbes responsible for these diarrheal diseases.

Methodology

Previous immunoinformatics study predicted a potential peptide from the Ferric enterobactin protein (FepA) of Shigella spp. In this study, we have chemically synthesized the FepA peptide. As a highly immunogenic, FepA peptide conjugated with KLH has been tested in mice model with complete and incomplete adjuvants as a vaccine candidate.

Results

Immunological analysis showed that all vaccinated mice were immunologically boosted, which was statistically significant (P-value 0.0325) compared to control mice. Immunological analysis for bacterial neutralization test result was also statistically significant (P-value 0.0468), where each ELISA plate was coated with 1 × 10⁷ S. flexneri cells. The Challenge test with 1 × 10¹² S. flexneri cells to each vaccinated and controlled mice showed that 37.5 % of control (non-vaccinated) mice died within seven days after the challenge was given while 100 % of vaccinated mice remained strong and stout. The analyses of the post-challenge weight loss of the mice were also significant (P-value 0.0367) as the weight loss percentage in control mice was much higher than in the vaccinated mice. The pathological and phenotypic appearances of vaccinated mice were also clearly differentiable compared with control mice. Thus all these immunological analysis and pathological appearances directly supported our FepA peptide as a potential immune booster.

Conclusion

This study provides evidence that the FepA peptide is a highly immunogenic vaccine candidate against S. flexneri. Therefore, these findings inspire future trials for the evaluation of the suitability of this vaccine candidate against Shigellosis.

Objective

Breakthrough COVID-19 infections are common following immunisation with various types of vaccines. The patterns of infections have not been well established. We aimed to analyse the signs and symptoms of post vaccination infections in addition to the need for hospital admission, ER visit and supplemental oxygen in relation to age and gender.

Methods

A cross-sectional cohort study was conducted in JUH from March 2021 to August 2022, we interviewed 1479 individuals who are >15 years of age and got a breakthrough infection. The statistical analysis was performed using STATA statistical software.

Results

Out of the 1479 cases, 50.2 % and 69.4 % were females and less than 45 years of age respectively. Symptoms of cough, fever and headache were reported by nearly 50 % of the patients, while one-third complained of dyspnoea. We found that participants older than 45 years had worse clinical outcomes (P-value < 0.001). 13 deaths were identified in this study due to breakthrough infection, 92.3 % of them were older than 45 years (P-value < 0.001). Participants ≥45 years who experienced a breakthrough infection of COVID-19 were 0.7 times less likely to be females using adjusted logistic regression.

Conclusion

This study indicates that despite more severe symptoms reported in younger patients, the major clinical outcomes were worse among older patients, which makes age a major risk for poor outcomes regardless of symptoms. Thus, older people should be evaluated carefully when presenting with mild symptoms of COVID-19 breakthrough infection. The study also confirms that there is no difference in the incidence of COVID-19 breakthrough infections between males and females. Prospective studies are needed to risk stratify COVID-19 breakthrough infections, which should take into account variants of the virus and comorbidities.