The clinical development process for a novel preventive vaccine: An overview

Positive and negative factors of parents vaccinating their children against COVID-19: An umbrella review

Purpose

This umbrella review summarized the factors influencing parents' hesitancy to vaccinate their children against COVID-19 and the evidence to reduce it.

Methods

The analysis included PubMed, Embase, Cochrane Library, Web of Science, and Scopus articles published before March 22, 2024. It considered all meta-analyses that investigated parental COVID-19 vaccine hesitancy.

Results

Eight studies were included. Hesitancy rate of parents from five continents to vaccinate their children against COVID-19 was between 0.69 % and 95.0 %. The comprehensive synthesis in this review shows that the influencing factors originate from four aspects: Parents' attitudes, including their trust in the scientific community, concerns about COVID-19 complications, perceptions of children's susceptibility, and support from the social environment, including government incentives, low vaccination costs, and specific sociodemographic characteristics, were positive factors that reduced parental vaccine hesitancy in children. Conversely, negative aspects, including vaccine distrust, the spread of misinformation, poor economic status, and concern about unprecedentedly short development time, were associated with increased hesitancy.

Conclusion

Our study identified positive and negative factors for parental COVID-19 vaccine hesitancy in children and highlighted that parental attitude was the most important determinant.

Vaccine safety beliefs in the state of Alaska

Objectives

Identifying the key factors associated with vaccine hesitancy remains a challenge as has been highlighted throughout the COVID-19 vaccine roll out and pandemic. The aim of this study was to determine characteristics associated with vaccine safety and compare perceived safety by vaccine. Our hypothesis is that vaccine safety perception will vary by vaccine with COVID-19 as ranked lowest for safety.

Study design

Cross sectional.

Methods

A statewide sample (n = 1024) responded to an online 28-point questionnaire via anonymous linked invitation.

Results

Among the eight vaccines assessed, COVID-19 had the lowest perceived safety (53.13%) followed by human papillomavirus HPV (63.38%). A binomial logistic regression assessed COVID-19 vaccine safety beliefs (safe v not safe) finding age, political orientation, and perceived safety of certain vaccines as statistically significant. As age increased by year, vaccine safety beliefs increased. Persons who identified as conservative demonstrated less belief in vaccine safety than all other groups. Among persons who did not perceive the COVID-19 vaccine as safe, 65.8% believed chicken pox was safe, 63.3% and 61.1% perceived hepatitis A& B were safe.

Conclusions

These findings demonstrate that vaccine safety beliefs differ by vaccine and that persons who do not believe in the safety of the COVID-19 are not exclusively against all vaccines. Understanding factors that increase vaccine safety by vaccine could assist in developing an intervention which could increase belief in safety for all vaccines.

Health literacy and COVID-19 vaccine acceptance worldwide: A systematic review

Objective

Health literacy helps an individual to have the capacity to obtain, process, and understand basic health information to make appropriate health decisions. This study aimed to review the association between health literacy and COVID-19 vaccine acceptance.

Method

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses steps. Databases including PubMed/MEDLINE, Web of Science, Scopus, EMBASE, World Health Organization libraries, and Google Scholar were used to search all published articles in the area of health literacy and COVID-19 vaccine acceptance until August 1, 2022.

Result

In this review, 1348 articles were retrieved. Finally, 13 articles were included in the review after the removal of duplicates that did not meet our inclusion criteria. In all, 10 articles showed that health literacy was significantly associated with COVID-19 vaccine acceptance. This review also showed that positive perception of the vaccine, vaccine hesitancy, adverse reaction from vaccines, residence, socioeconomic status, level of education, younger age, being a health worker, and positive belief have associations with health literacy and COVID-19 vaccine acceptance. There was significant heterogeneity in the study population and measurement tools used for health literacy and COVID-19 vaccine acceptance.

Conclusion

This systematic review provides comprehensive evidence on health literacy and COVID-19 vaccine acceptance globally. There was significant heterogeneity in the study population and measurement tools used for health literacy and COVID-19 vaccine acceptance. Most studies reported that health literacy is significantly associated with COVID-19 vaccine acceptance. Therefore, investing in health literacy using different vaccine promotion strategies may improve COVID-19 vaccine acceptance and health decision-making to decrease the impact of the COVID-19 pandemic.

A Phase I study to evaluate safety and tolerability of DTaP-IPV + Hib vaccine in healthy adult volunteers in India

Background

To assess safety and tolerability of a diphtheria and tetanus toxoid, acellular pertussis, inactivated poliovirus and Haemophilus influenza type B conjugate adsorbed vaccine (DTaP-IPV + Hib), manufactured by Serum Institute of India Pvt. Ltd. (SIIPL)'s, the current first-in-human Phase 1 study was conducted in healthy adults.

Methods

Vaccine was administered as a single 0.5 mL dose intramuscularly into deltoid muscle of 24 healthy adults aged 18-45 years, who were then followed prospectively for one month for safety outcomes.

Results

All 24 participants completed the study in compliance with protocol. Four solicited adverse events were reported in three participants during the study; all adverse events were mild and recovered completely. No deaths, unsolicited adverse events, or serious adverse events were reported.

Conclusion

SIIPL DTaP-IPV + Hib vaccine was well tolerated and safe in study subjects. Further clinical development will be conducted to assess safety and immunogenicity in young children, the target population.Clinical Trial Registration: CTRI/2017/07/009034.

Why do people take part in vaccine trials? A mixed methods narrative synthesis

OBJECTIVES

To understand why individuals do or do not take part in vaccine trials, exploring the motivators and barriers to identify effective strategies to optimise recruitment in vaccine research.

METHODS

Qualitative studies and quantitative surveys capturing data on reasons for trial participation/decline were included. Six databases were searched from 1996 to October 2021. Two reviewers independently screened and assessed risk of bias. Results were reported narratively and analysed using thematic analysis.

RESULTS

We included 32 studies (17 qualitative; 12 quantitative; 3 mixed-methods) that covered a wide range of populations, geographical areas and disease types. Eight themes were identified 1) altruism; 2) potential for personal benefit; 3) perceived risks; 4) trust or distrust; 5) social networks; 6) stigma; 7) practical implications; 8) research vanguard.

CONCLUSION

Our findings provide a detailed description of how potential participants weigh up their decisions to participate in vaccine trials, which could inform the planning and implementation of studies to enhance recruitment.

PRACTICE IMPLICATIONS

Clinical trial researchers should consider a patient-centered approach to recruitment, tailoring promoting material and attempt to understand fears, stigma and perceived risks. In addition, recognising the importance of trust and the key role friends, communities, family, and those in supervisory positions play in decisions.

COVID-19 adenovirus vector vaccine induces higher interferon and pro-inflammatory responses than mRNA vaccines in human PBMCs, macrophages and moDCs

BACKGROUND

During the COVID-19 pandemic multiple vaccines were rapidly developed and widely used throughout the world. At present there is very little information on COVID-19 vaccine interactions with primary human immune cells such as peripheral blood mononuclear cells (PBMCs), monocyte-derived macrophages and dendritic cells (moDCs).

METHODS

Human PBMCs, macrophages and moDCs were stimulated with different COVID-19 vaccines, and the expression of interferon (IFN-λ1, IFN-α1), pro-inflammatory (IL-1β, IL-6, IL-8, IL-18, CXCL-4, CXCL-10, TNF-α) and Th1-type cytokine mRNAs (IL-2, IFN-γ) were analyzed by qPCR. In addition, the expression of vaccine induced spike (S) protein and antiviral molecules were studied in primary immune cells and in A549 lung epithelial cells.

RESULTS

Adenovirus vector (Ad-vector) vaccine AZD1222 induced high levels of IFN-λ1, IFN-α1, CXCL-10, IL-6, and TNF-α mRNAs in PBMCs at early time points of stimulation while the expression of IFN-γ and IL-2 mRNA took place at later times. AZD1222 also induced IFN-λ1, CXCL-10 and IL-6 mRNA expression in monocyte-derived macrophages and DCs in a dose-dependent fashion. AZD1222 also activated the phosphorylation of IRF3 and induced MxA expression. BNT162b2 and mRNA-1273 mRNA vaccines failed to induce or induced very weak cytokine gene expression in all cell models. None of the vaccines enhanced the expression of CXCL-4. AZD1222 and mRNA-1273 vaccines induced high expression of S protein in all studied cells.

CONCLUSIONS

Ad-vector vaccine induces higher IFN and pro-inflammatory responses than the mRNA vaccines in human immune cells. This data shows that AZD1222 readily activates IFN and pro-inflammatory cytokine gene expression in PBMCs, macrophages and DCs, but fails to further enhance CXCL-4 mRNA expression.

An update on COVID-19: SARS-CoV-2 variants, antiviral drugs, and vaccines

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious and pathogenic virus that first appeared in late December 2019. This SARS-CoV-2 causes an infection of an acute respiratory disease called "coronavirus infectious disease-2019 (COVID-19). The World Health Organization (WHO) declared this SARS-CoV-2 outbreak a great pandemic on March 11, 2020. As of January 31, 2023, SARS-CoV-2 recorded more than 67 million cases and over 6 million deaths. Recently, novel mutated variants of SARS-CoV are also creating a serious health concern worldwide, and the future novel variant is still mysterious. As infection cases of SARS-CoV-2 are increasing daily, scientists are trying to combat the disease using numerous antiviral drugs and vaccines against SARS-CoV-2. To our knowledge, this is the first comprehensive review that summarized the dynamic nature of SARS-CoV-2 transmission, SARS-CoV-2 variants (a variant of concern and variant of interest), antiviral drugs and vaccines utilized against SARS-CoV-2 at a glance. Hopefully, this review will enable the researcher to gain knowledge on SARS-CoV-2 variants and vaccines, which will also pave the way to identify efficient novel vaccines against forthcoming SARS-CoV-2 strains.

Ethics of age de-escalation in pediatric vaccine trials: Attending to the case of COVID-19

In the development of new vaccines, many trials use age de-escalation: after establishing safety and efficacy in adult populations, progressively younger cohorts are enrolled and studied. Age de-escalation promotes many values. The responsibility to protect children from potential risks of experimental vaccines is significant, not only given increased risks of adverse effects but also because parents and medical professionals have a moral responsibility to protect children from harms associated with novel, uncertain interventions. Further, given that young children cannot provide informed consent, acceptable risks for research requiring proxy consent are lower than for adults making decisions for themselves. Although age de-escalation approaches are widely used in vaccine trials, including notably in the recent development of pediatric COVID-19 vaccines, ethicists have not addressed the benefits and risks of these approaches. Their benefits are largely assumed and unstated, while their potential risks are usually overlooked. There are no official ethics guidelines for the use of age de-escalation in clinical research. In this paper, we provide a systematic account of key moral factors to consider when employing age de-escalation. Analyzing pediatric COVID-19 vaccine development as our key case study, we clarify the benefits, risks, and trade-offs involved in age de-escalation approaches and call for the development of evidence-based best practice guidelines to identify when age de-escalation is likely to be an ethical strategy in vaccine development.

ViralVacDB: A manually curated repository of viral vaccines

Over the years, numerous vaccines have been developed against viral infections; however, a complete database that provides comprehensive information on viral vaccines has been lacking. In this review, along with our freely accessible database ViralVacDB, we provide details of the viral vaccines, their type, routes of administration and approving agencies. This repository systematically covers additional information such as disease name, adjuvant, manufacturer, clinical status, age and dosage against 422 viral vaccines, including 145 approved vaccines and 277 in clinical trials. We anticipate that this database will be highly beneficial to researchers and others working in pharmaceuticals and immuno-informatics.

Overview of the global vaccine ecosystem

INTRODUCTION

Vaccination is an effective, relatively inexpensive, and easy to deliver approach to combating infectious diseases. Widespread vaccination of children has led to the eradication of smallpox and allowed for regional elimination or control of diseases like polio, measles, mumps, tetanus, diphtheria, and whooping cough. But, as we learned from efforts to combat the COVID-19 pandemic, a successful global vaccination program must overcome several hurdles. Failure at any stage can limit vaccine uptake and disease control.

AREAS COVERED

In this review, we break down the vaccine journey from research and development to delivery into several steps. We also list all the important international organizations trying to support this ecosystem. Then we identify the role of each of these organizations in supporting each of the necessary steps for a successful vaccination program.

EXPERT OPINION

The bottlenecks in vaccination can be different for different countries, based on their income and geography. Policy makers need to identify the weaknesses of this ecosystem in different regions of the world and make sure there is adequate global and local support to fill the gaps in the system.

Safety, immunogenicity and non-interference of concomitant Typhoid Vi capsular polysaccharide-tetanus toxoid conjugate vaccine (Typbar-TCV®) and measles or measles-mumps-rubella vaccines in 8-9 months-old Indian children

We evaluated safety, reactogenicity, and immunogenicity when the WHO-prequalified single-dose Typhoid Vi-polysaccharide conjugate vaccine, Typbar-TCV®, was administered concomitantly with measles (MV) or measles-mumps-rubella (MMR) vaccines in 8- or 9-month-old children. We enrolled 493 children who were randomized 2:1:1:1 to four groups to receive either TCV (0.5 mL intramuscularly) and MV (0.5 ml subcutaneously) concomitantly at 9 months of age (Group 1) with two subgroups given TCV booster 28 days (Group 1A) or 180 days (Group 1B) later, or MV on Day 0 and TCV on Day 28 (Group 2); or TCV at 8 months of age and MV 28 days later (Group 3), or MV only at 9 months of age (Group 4). All children received MMR at 15 months of age. We observed no statistically significant differences between group rates of solicited or unsolicited adverse events assessed throughout the study. Seroconversion rates for measles, mumps, and rubella antibodies were unaffected by concomitant administration with TCV, being similar in Groups 1, 2, and 3 and comparable to Group 4 (Control). IgG anti-Vi antibody titers were similar in all groups after primary Typbar-TCV® vaccination and were not increased by a second dose 28 days later. A small response to a booster dose of Typbar-TCV® given at 180 days did not achieve the high titers observed after the first dose, suggesting that booster vaccination may be more effective after a longer interval than 6 months. Typbar-TCV® can be safely co-administered with measles and MMR vaccines in children aged ≥9 months.Clinical trial registration number: CTRI/2014/04/004532.

Appraisal of SARS-CoV-2 mutations and their impact on vaccination efficacy: an overview

With the unexpected emergence of the novel 2019 Wuhan coronavirus, the world was faced with a sudden uproar that quickly shifted into a serious life-threatening pandemic. Affecting the lives of the global population and leaving drastic damage in various sections and systems, several measures have been constantly taken to tackle down this crisis. For instance, numerous vaccines have been developed in the past two years, some of which have been granted emergency use, thus providing sufficient immunity to the vaccinated individuals. However, the appearance of newly emerged SARS-CoV-2 variants with accelerated transmission and fatality has led the world towards another pandemic. Having undergone various mutations in genomic and/or amino acid profiles, some of the emerged variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta have displayed immune evasion and pathogenicity even in the vaccinated population, hence raising concerns regarding the efficacy of current vaccines against new VOCs of COVID-19. Therefore, genomic investigations of SARS-CoV-2 mutations are expected to provide valuable insight into the evolution of SARS-CoV-2, while also determining the impact of different mutations on infection severity. This study was constructed with the aim of shining light on recent advances regarding mutations in major COVID-19 VOCs, as well as vaccination efficacy against those VOCs.

Artificial Intelligence-Based Data-Driven Strategy to Accelerate Research, Development, and Clinical Trials of COVID Vaccine

The global COVID-19 (coronavirus disease 2019) pandemic, which was caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a significant loss of human life around the world. The SARS-CoV-2 has caused significant problems to medical systems and healthcare facilities due to its unexpected global expansion. Despite all of the efforts, developing effective treatments, diagnostic techniques, and vaccinations for this unique virus is a top priority and takes a long time. However, the foremost step in vaccine development is to identify possible antigens for a vaccine. The traditional method was time taking, but after the breakthrough technology of reverse vaccinology (RV) was introduced in 2000, it drastically lowers the time needed to detect antigens ranging from 5-15 years to 1-2 years. The different RV tools work based on machine learning (ML) and artificial intelligence (AI). Models based on AI and ML have shown promising solutions in accelerating the discovery and optimization of new antivirals or effective vaccine candidates. In the present scenario, AI has been extensively used for drug and vaccine research against SARS-COV-2 therapy discovery. This is more useful for the identification of potential existing drugs with inhibitory human coronavirus by using different datasets. The AI tools and computational approaches have led to speedy research and the development of a vaccine to fight against the coronavirus. Therefore, this paper suggests the role of artificial intelligence in the field of clinical trials of vaccines and clinical practices using different tools.

The Promises of Speeding Up: Changes in Requirements for Animal Studies and Alternatives during COVID-19 Vaccine Approval–A Case Study

Simple Summary

The COVID-19 pandemic led to intensive research into finding new vaccines for human protection. On 21 December 2020, the European Commission granted conditional marketing authorisation for the messenger RNA vaccine ‘Comirnaty’, produced by Pfizer (New York, NY, USA) and BioNTech (Mainz, Germany). This happened only twelve months after the first identification of the virus, whereas the development and approval of vaccines usually take ten years. Through document analysis and interviewing key expert stakeholders, we examined whether the role of animal studies and alternatives in this fast approval process had changed and, if so, whether this could lead to using fewer animal studies and more alternatives in the future. It turned out that in this case, for vaccine development and production, the number of animal studies performed and required had indeed declined, more alternatives had been used and accepted, human studies started earlier and ran in parallel with (rather than sequential to) animal studies, and regulators accepted historical data from earlier vaccine research. The Pfizer/BioNTech vaccine case illustrates the tremendous progress in quickly producing and authorising reliable, safe and effective vaccines, using fewer animal studies and more alternatives. It is time to study the broader implementation of these new procedures on a larger scale to benefit animals and humans.

Abstract

On 21 December 2020, the European Commission granted conditional marketing authorisation for the BNT162b2 COVID-19 vaccine ‘Comirnaty’, produced by Pfizer/BioNTech. This happened only twelve months after scientists first identified SARS-CoV-2. This stands in stark contrast with the usual ten years needed for vaccine development and approval. Many have suggested that the changes in required animal tests have sped up the development of Comirnaty and other vaccine candidates. However, few have provided an overview of the changes made and interviewed stakeholders on the potential of the pandemic’s pressure to achieve a lasting impact. Our research question is: how have stakeholders, including regulatory agencies and pharmaceutical companies, dealt with requirements concerning in vivo animal models in the expedited approval of vaccine candidates such as ‘Comirnaty’? We interviewed key stakeholders at the Dutch national and European levels (n = 11 individuals representing five stakeholder groups in eight interviews and two written statements) and analysed relevant publications, policy documents and other grey literature (n = 171 documents). Interviewees observed significant changes in regulatory procedures and requirements for the ‘Comirnaty’ vaccine compared to vaccine approval in non-pandemic circumstances. Specifically, the European Medicines Agency (EMA) actively promoted changes by using an accelerated assessment and rolling review procedure for fast conditional marketing authorisation, requiring a reduced number of animal studies and accepting more alternatives, allowing pre-clinical in vivo animal experiments to run in parallel with clinical trials and allowing re-use of historical data from earlier vaccine research. Pharmaceutical companies, in turn, actively anticipated these changes and contributed data from non-animal alternative sources for the development phase. After approval, they could also use in vitro methods only for all batch releases due to the thorough characterisation of the mRNA vaccine. Pharmaceutical companies were optimistic about future change because of societal concerns surrounding the use of animals, adding that, in their view, non-animal alternatives generally obtain faster, better, and cheaper results. Regulators we interviewed were more hesitant to permanently implement these changes as they feared backlash regarding safety issues and uncertainty surrounding adverse effects. Our analysis shows how the EMA shortened its approval timeline in times of crisis by reducing the number of requested animal studies and promoting alternative methods. It also highlights the readiness of pharmaceutical companies to contribute to these changes. More research is warranted to investigate these promising possibilities toward further replacement in science and regulations, contributing to faster vaccine development.

Learnings from COVID-19 for managing humanitarian supply chains: systematic literature review and future research directions

The COVID-19 pandemic has been experienced as the most significant global disaster after the Spanish flue in 1918. Millions of people lost their life due to a lack of preparedness and ineffective strategies for managing humanitarian supply chains (HSC). Based on the learnings from this pandemic outbreak, different strategies for managing the effective HSC have been explored in the present context of pandemics through a systematic literature review. The findings highlight some of the major challenges faced during the COVID-19 pandemic, such as lack of planning and preparedness, extended shortages of essential lifesaving items, inadequate lab capacity, lack of transparency and visibility, inefficient distribution network, high response time, dependencies on single sourcing for the medical equipment and medicines, lack of the right information on time, and lack of awareness about the protocol for the treatment of the viral disease. Some of the significant learnings observed from this analysis are the use of multiple sourcing of essential items, joint procurement, improving collaboration among all stakeholders, applications of IoT and blockchain technologies for improving tracking and traceability of essential commodities, application of data analytics tools for accurate prediction of next possible COVID wave/disruptions and optimization of distribution network. Limited studies are focused on finding solutions to these problems in managing HSC. Therefore, as a future scope, researchers could find solutions to optimizing the distribution network in context to pandemics, improving tracing and tracking of items during sudden demand, improving trust and collaborations among different agencies involved in HSC.

Predictors of Survival after Vaccination in a Pneumonic Plague Model

Background: The need for an updated plague vaccine is highlighted by outbreaks in endemic regions together with the pandemic potential of this disease. There is no easily available, approved vaccine. Methods: Here we have used a murine model of pneumonic plague to examine the factors that maximise immunogenicity and contribute to survival following vaccination. We varied vaccine type, as either a genetic fusion of the F1 and V protein antigens or a mixture of these two recombinant antigens, as well as antigen dose-level and formulation in order to correlate immune response to survival. Results: Whilst there was interaction between each of the variables of vaccine type, dose level and formulation and these all contributed to survival, vaccine formulation in protein-coated microcrystals (PCMCs) was the key contributor in inducing antibody titres. From these data, we propose a cut-off in total serum antibody titre to the F1 and V proteins of 100 µg/mL and 200 µg/mL, respectively. At these thresholds, survival is predicted in this murine pneumonic model to be >90%. Within the total titre of antibody to the V antigen, the neutralising antibody component correlated with dose level and was enhanced when the V antigen in free form was formulated in PCMCs. Antibody titre to F1 was limited by fusion to V, but this was compensated for by PCMC formulation. Conclusions: These data will enable clinical assessment of this and other candidate plague vaccines that utilise the same vaccine antigens by identifying a target antibody titre from murine models, which will guide the evaluation of clinical titres as serological surrogate markers of efficacy.

From Bench to the Clinic: The Path to Translation of Nanotechnology-Enabled mRNA SARS-CoV-2 Vaccines

During the last decades, the use of nanotechnology in medicine has effectively been translated to the design of drug delivery systems, nanostructured tissues, diagnostic platforms, and novel nanomaterials against several human diseases and infectious pathogens. Nanotechnology-enabled vaccines have been positioned as solutions to mitigate the pandemic outbreak caused by the novel pathogen severe acute respiratory syndrome coronavirus 2. To fast-track the development of vaccines, unprecedented industrial and academic collaborations emerged around the world, resulting in the clinical translation of effective vaccines in less than one year. In this article, we provide an overview of the path to translation from the bench to the clinic of nanotechnology-enabled messenger ribonucleic acid vaccines and examine in detail the types of delivery systems used, their mechanisms of action, obtained results during each phase of their clinical development and their regulatory approval process. We also analyze how nanotechnology is impacting global health and economy during the COVID-19 pandemic and beyond.

COVID-19 phase 4 vaccine candidates, effectiveness on SARS-CoV-2 variants, neutralizing antibody, rare side effects, traditional and nano-based vaccine platforms: a review

The COVID-19 pandemic has endangered world health and the economy. As the number of cases is increasing, different companies have started developing potential vaccines using both traditional and nano-based platforms to overcome the pandemic. Several countries have approved a few vaccine candidates for emergency use authorization (EUA), showing significant effectiveness and inducing a robust immune response. Oxford-AstraZeneca, Pfizer-BioNTech's BNT162, Moderna's mRNA-1273, Sinovac's CoronaVac, Johnson & Johnson, Sputnik-V, and Sinopharm's vaccine candidates are leading the race. However, the SARS-CoV-2 is constantly mutating, making the vaccines less effective, possibly by escaping immune response for some variants. Besides, some EUA vaccines have been reported to induce rare side effects such as blood clots, cardiac injury, anaphylaxis, and some neurological effects. Although the COVID-19 vaccine candidates promise to overcome the pandemic, a more significant and clear understanding is needed. In this review, we brief about the clinical trial of some leading candidates, their effectiveness, and their neutralizing effect on SARS-CoV-2 variants. Further, we have discussed the rare side effects, different traditional and nano-based platforms to understand the scope of future development.

A Meta-Analysis on the Safety and Immunogenicity of Covid-19 Vaccines

Objective:

The presented meta-analysis (MA) aims at identifying the vaccine safety and immunogenicity in published trials about SARS-CoV-2 vaccines.

Methods:

All relevant publications were systematically searched and collected from different databases (Embase, Scopus, EBSCO, MEDLINE central/PubMed, Science Direct, Cochrane Central Register for Clinical Trials (CENTRAL), Clinical Trials.gov, WHO International Clinical Trials Registry Platform (ICTRP), COVID Trial, COVID Inato, Web of Science, ProQuest Thesis, ProQuest Coronavirus Database, SAGE Thesis, Google Scholar, Research Square, and Medxriv) up to January 10, 2021. The pooled vaccine safety and immunogenicity following vaccination in phase 1 and 2 vaccine clinical trials, as well as their 95% confidence intervals (CI), were estimated using the random-effects model.

Results:

The predefined inclusion criteria were met in 22 out of 8592 articles. The proportion of anti-severe acute respiratory distress coronavirus 2 (SARS-CoV-2) antibody responses after 7 days among 72 vaccinated persons included in 1 study was 81% (95% CI: 70-89), after 14 days among 888 vaccinated persons included in 6 studies was 80% (95% CI: 58-92), after 28 days among 1589 vaccinated persons included in 6 studies was 63% (95% CI: 59-67), after 42 days among 478 vaccinated persons included in 5 studies was 93% (95% CI: 80-98), and after 56 days among 432 vaccinated persons included in 2 studies was 93% (95% CI: 83-97). Meta regression explains more than 80% of this heterogeneity, where the main predictors were; the inactivated vaccine type (β = 2.027, P = 0.0007), measurement of antibodies at week 1 (β = −4.327, P < 0.0001) and at week 3 of the first dose (β = −2.02, P = 0.0025). Furthermore, the pooled proportion adverse effects 7 days after vaccination was 0.01 (0.08-0.14) for fever, headache 0.23 (0.19-0.27), fatigue 0.10 (0.07-0.13), and 0.18 (0.14-0.23) for muscle pain.

Conclusion:

Immunogenicity following vaccination ranged from 63% to 93% depending on the time at which the antibody levels were measured.

In-line treatments and clinical initiatives to fight against COVID-19 outbreak

In December 2019, when the whole world is waiting for Christmas and New Year, the physicians of Wuhan, China, are astounded by clusters of patients suffering from pneumonia from unknown causes. The pathogen isolated from the respiratory epithelium of the patients is similar to previously known coronaviruses with some distinct features. The disease was initially called nCoV-2019 or SARS-nCoV-2 and later termed as COVID-19 by WHO. The infection is rapidly propagating from the day of emergence, spread throughout the globe and now became a pandemic which challenged the competencies of developed nations in terms of health care management. As per WHO report, 216 countries are affected with SARS-CoV-19 by August 5, 2020 with 18, 142, 718 confirmed cases and 691,013 deaths reports. Such huge mortality and morbidity rates are truly threatening and calls for some aggressive and effective measures to slow down the disease transmission. The scientists are constantly engaged in finding a potential solution to diagnose and treat the pandemic. Various FDA approved drugs with the previous history of antiviral potency are repurposed for COVID-19 treatment. Different drugs and vaccines are under clinical trials and some rapid and effective diagnostic tools are also under development. In this review, we have highlighted the current epidemiology through infographics, disease transmission and progression, clinical features and diagnosis and possible therapeutic approaches for COVID-19. The article mainly focused on the development and possible application of various FDA approved drugs, including chloroquine, remdesivir, favipiravir, nefamostate mesylate, penciclovir, nitazoxanide, ribavirin etc., vaccines under development and various registered clinical trials exploring different therapeutic measures for the treatment of COVID-19. This information will definitely help the researchers to understand the in-line scientific progress by various clinical agencies and regulatory bodies against COVID-19.

Rapid, high throughput protein estimation method for saponin and alhydrogel adjuvanted R21 VLP Malaria vaccine based on intrinsic fluorescence

Protein content estimation of recombinant vaccines at drug product (DP) stage is a crucial lot release and stability indicating assay in biopharmaceutical industries. Regulatory bodies such as US-FDA and WHO necessitates the quantitation of protein content to assess process parameters as well as formulation losses. Estimation of protein content at DP stage in presence of adjuvants (e.g AlOOH, AlPO₄, saponin and squalene) is quite challenging, and the challenge intensifies when the target protein is in Virus like particles (VLP) form, owing to its size and structural complexity. Methods available for protein estimation of adjuvanted vaccines mostly suffer from inaccuracy at lower protein concentrations and in most cases require antigen desorption before analysis. Present research work is based on the development of a rapid plate-based method for protein estimation through intrinsic fluorescence by using Malaria vaccine R21 VLP as a model protein. Present method exhibited linearity for protein estimation of R21, in the range of 5-30 µg/mL in Alhydrogel and 4-20 µg/mL for Matrix M adjuvant. The method was validated as per ICH guidelines. The limit of quantification was found to be 0.94 µg/mL for both Alhydrogel and Matrix M adjuvanted R21. The method was found specific, precise and repeatable. This method is superior in terms of less sample quantity requirement, multiple sample analysis, short turnaround time and is non-invasive. This method was found to be stability indicating, works for other proteins containing tryptophan residues and operates well even in presence of host cell proteins. Based on the study, present method can be used in vaccine industries for routine in-process sample analysis (both inline and offline), lot release of VLP based drug products in presence of Alhydrogel and saponin based adjuvant systems.

Coronavirus disease 2019 vaccine: An overview of the progression and current use

On December 31, 2019; unidentified pneumonia cases were reported from China. It was soon announced that these cases were of viral origin and the cause was a new coronavirus (CoV). Initially, the virus was called "novel CoV " and then defined as "severe acute respiratory syndrome CoV 2 (SARS-CoV-2)" after more detailed investigations. The disease caused by SARS-CoV-2 was named CoV disease 2019 (COVID-19) by the World Health Organization. The rapid spread of the disease in a few months has resulted in a global pandemic and it continues. However, there are no specific effective anti-viral drugs for SARS-CoV-2 infection, some antiviral drugs are using in the therapy of COVID-19 with limited success. Currently, for the prevention of the pandemic, global vaccination seems to be important. Antiviral protection of vaccines is provided by the development of antibodies that can neutralize the virus. Antibody response develops against spike protein and nucleocapsid protein but neutralizing antibodies are formed against the receptor-binding domain of the spike protein. It has also been shown that most viral proteins are recognized in T-cell responses. Vaccine discovery trials for COVID-19 have begun all over the world since the outbreak began. More than 100 vaccine studies against COVID-19 have been published in the last year. Some of them were urgently approved and used worldwide. The current study aimed to review the progression and current use of COVID-19 vaccines.

Microbes, Clinical trials, Drug Discovery, and Vaccine Development: The Current Perspectives

Because of the frequent emergence of novel microbial species and the re-emergence of genetic variants of hitherto known microbes, the global healthcare system, and human health has been thrown into jeopardy. Also, certain microbes that possess the ability to develop multi-drug resistance (MDR) have limited the treatment options in cases of serious infections, and increased hospital and treatment costs, and associated morbidity and mortality. The recent discovery of the novel Coronavirus (n-CoV), the Severe Acute Respiratory Syndrome CoV-2 (SARS-CoV-2) that is causing the CoV Disease-19 (COVID-19) has resulted in severe morbidity and mortality throughout the world affecting normal human lives. The major concern with the current pandemic is the non-availability of specific drugs and an incomplete understanding of the pathobiology of the virus. It is therefore important for pharmaceutical establishments to envisage the discovery of therapeutic interventions and potential vaccines against the novel and MDR microbes. Therefore, this review is attempted to update and explore the current perspectives in microbes, clinical research, drug discovery, and vaccine development to effectively combat the emerging novel and re-emerging genetic variants of microbes.

A Review of UK-Registered and Candidate Vaccines for Bovine Respiratory Disease

Vaccination is widely regarded as a cornerstone in animal or herd health and infectious disease management. Nineteen vaccines against the major pathogens implicated in bovine respiratory disease are registered for use in the UK by the Veterinary Medicines Directorate (VMD). However, despite annual prophylactic vaccination, bovine respiratory disease is still conservatively estimated to cost the UK economy approximately £80 million per annum. This review examines the vaccine types available, discusses the surrounding literature and scientific rationale of the limitations and assesses the potential of novel vaccine technologies.

Africa's preparedness towards COVID-19 vaccines: Demand and acceptability challenges

To date, the response to coronavirus disease (COVID-19) in many African countries has been quick, forward-looking and adjustable in spite of the continent's limited resources. These responses were triggered by the continuous increase in cases and deaths, which have necessitated speedy development of an effective vaccine. It is anticipated that African governments and public health officials will show more transparency, and provide evidence-based strategies to support COVID-19 vaccines and design equitable as well as effective vaccine delivery plans for the populace. To this end, this review analysed Africa's preparedness and response towards COVID-19 vaccines, potential demand, acceptability and distribution challenges related to the management of the virus. The review takes stock of context-specific vaccine preparedness; the demand for vaccine and associated challenges; as well as vaccine accessibility and its distribution. The review offers insightful approaches and strategies by which African countries can maximize benefits from the COVID-19 vaccines to overcome the virus. These include the pursuance of vaccines that may help confer immunity or protection against the virus in the light of contextual circumstances of specific African countries, including sociocultural and economic issues among other factors.

Vaccine and vaccination as a part of human life: In view of COVID-19

Background

Vaccination created a great breakthrough toward the improvement to the global health. The development of vaccines and their use made a substantial decrease and control in infectious diseases. The abundance and emergence of new vaccines has facilitated targeting populations to alleviate and eliminate contagious pathogens from their innate reservoir. However, along with the infections like malaria and HIV, effective immunization remains obscure and imparts a great challenge to science.

Purpose and scope

The novel Corona virus SARS‐CoV‐2 is the reason for the 2019 COVID‐19 pandemic in the human global population, in the first half of 2019. The need for establishing a protected and compelling COVID‐19 immunization is a global prerequisite to end this pandemic.

Summary and conclusion

The different vaccine technologies like inactivation, attenuation, nucleic acid, viral vector, subunit, and viral particle based techniques are employed to develop a safe and highly efficient vaccine. The progress in vaccine development for SARS‐CoV2 is much faster in the history of science. Even though there exist of lot of limitations, continuous efforts has put forward so as to develop highly competent and effective vaccine for many human and animal linked diseases due to its unlimited prospective. This review article focuses on the historical outlook and the development of the vaccine as it is a crucial area of research where the life of the human is saved from various potential diseases.

Biomaterials, biological molecules, and polymers in developing vaccines

Vaccines have been used to train the immune system to recognize pathogens, and prevent and treat diseases, such as cancer, for decades. However, there are continuing challenges in their manufacturing, large-scale production, and storage. Some of them also show suboptimal immunogenicity, requiring additional adjuvants and booster doses. As an alternate vaccination strategy, a new class of biomimetic materials with unique functionalities has emerged in recent years. Here, we explore the current bioengineering techniques that make use of hydrogels, modified polymers, cell membranes, self-assembled proteins, virus-like particles (VLPs), and nucleic acids to deliver and develop biomaterial-based vaccines. We also review design principles and key regulatory issues associated with their development. Finally, we critically assess their limitations, explore approaches to overcome these limitations, and discuss potential future applications for clinical translation.

COVID-19 vaccine capacity: Challenges and mitigation - The DCVMN perspective

Vaccine manufacturers from developing countries have a proven track record of developing, producing, and supplying high-quality vaccines globally. However, due to the complexity of vaccine manufacturing, numerous stakeholder organizations support manufacturers across a variety of functions. To optimize the support from stakeholders it is instrumental to first understand which manufacturing processes these manufacturers require support for and what support functions are most beneficial. To this end, the Developing Countries Vaccine Manufacturers Network designed a comprehensive survey to assess the specific needs of the Network’s member organizations.

We found that almost all sampled manufacturers are interested in obtaining funding or technology transfers for COVID-19 vaccines. Furthermore, results indicated that manufacturers have a strong appetite for modern technology platforms, particularly RNA technologies. Scale-up, phase III clinical trials, and formulation were also key processes for which manufacturers require support.

SARS-CoV-2 vaccines elicit durable immune responses in infant rhesus macaques

The inclusion of infants in the SARS-CoV-2 vaccine roll-out is important to prevent severe complications of pediatric SARS-CoV-2 infections and to limit transmission and could possibly be implemented via the global pediatric vaccine schedule. However, age-dependent differences in immune function require careful evaluation of novel vaccines in the pediatric population. Toward this goal, we assessed the safety and immunogenicity of two SARS-CoV-2 vaccines. Two groups of 8 infant rhesus macaques (RMs) were immunized intramuscularly at weeks 0 and 4 with stabilized prefusion SARS-CoV-2 S-2P spike (S) protein encoded by mRNA encapsulated in lipid nanoparticles (mRNA-LNP) or the purified S protein mixed with 3M-052, a synthetic TLR7/8 agonist in a squalene emulsion (Protein+3M-052-SE). Neither vaccine induced adverse effects. Both vaccines elicited high magnitude IgG binding to RBD, N terminus domain, S1, and S2, ACE2 blocking activity, and high neutralizing antibody titers, all peaking at week 6. S-specific memory B cells were detected by week 4 and S-specific T cell responses were dominated by the production of IL-17, IFN-γ, or TNF-α. Antibody and cellular responses were stable through week 22. The immune responses for the mRNA-LNP vaccine were of a similar magnitude to those elicited by the Moderna mRNA-1273 vaccine in adults. The S-2P mRNA-LNP and Protein-3M-052-SE vaccines were well-tolerated and highly immunogenic in infant RMs, providing proof-of concept for a pediatric SARS-CoV-2 vaccine with the potential for durable immunity that might decrease the transmission of SARS-CoV-2 and mitigate the ongoing health and socioeconomic impacts of COVID-19.

Tweet Topics and Sentiments Relating to COVID-19 Vaccination Among Australian Twitter Users: Machine Learning Analysis

BACKGROUND

COVID-19 is one of the greatest threats to human beings in terms of health care, economy, and society in recent history. Up to this moment, there have been no signs of remission, and there is no proven effective cure. Vaccination is the primary biomedical preventive measure against the novel coronavirus. However, public bias or sentiments, as reflected on social media, may have a significant impact on the progression toward achieving herd immunity.

OBJECTIVE

This study aimed to use machine learning methods to extract topics and sentiments relating to COVID-19 vaccination on Twitter.

METHODS

We collected 31,100 English tweets containing COVID-19 vaccine-related keywords between January and October 2020 from Australian Twitter users. Specifically, we analyzed tweets by visualizing high-frequency word clouds and correlations between word tokens. We built a latent Dirichlet allocation (LDA) topic model to identify commonly discussed topics in a large sample of tweets. We also performed sentiment analysis to understand the overall sentiments and emotions related to COVID-19 vaccination in Australia.

RESULTS

Our analysis identified 3 LDA topics: (1) attitudes toward COVID-19 and its vaccination, (2) advocating infection control measures against COVID-19, and (3) misconceptions and complaints about COVID-19 control. Nearly two-thirds of the sentiments of all tweets expressed a positive public opinion about the COVID-19 vaccine; around one-third were negative. Among the 8 basic emotions, trust and anticipation were the two prominent positive emotions observed in the tweets, while fear was the top negative emotion.

CONCLUSIONS

Our findings indicate that some Twitter users in Australia supported infection control measures against COVID-19 and refuted misinformation. However, those who underestimated the risks and severity of COVID-19 may have rationalized their position on COVID-19 vaccination with conspiracy theories. We also noticed that the level of positive sentiment among the public may not be sufficient to increase vaccination coverage to a level high enough to achieve vaccination-induced herd immunity. Governments should explore public opinion and sentiments toward COVID-19 and COVID-19 vaccination, and implement an effective vaccination promotion scheme in addition to supporting the development and clinical administration of COVID-19 vaccines.

An Updated Review of SARS-CoV-2 Vaccines and the Importance of Effective Vaccination Programs in Pandemic Times

Since the worldwide COVID-19 pandemic was declared a year ago, the search for vaccines has become the top priority in order to restore normalcy after 2.5 million deaths worldwide, overloaded sanitary systems, and a huge economic burden. Vaccine development has represented a step towards the desired herd immunity in a short period of time, owing to a high level of investment, the focus of researchers, and the urge for the authorization of the faster administration of vaccines. Nevertheless, this objective may only be achieved by pursuing effective strategies and policies in various countries worldwide. In the present review, some aspects involved in accomplishing a successful vaccination program are addressed, in addition to the importance of vaccination in a pandemic in the face of unwillingness, conspiracy theories, or a lack of information among the public. Moreover, we provide some updated points related to the landscape of the clinical development of vaccine candidates, specifically, the top five vaccines that are already being assessed in Phase IV clinical trials (BNT162b2, mRNA-1273, AZD1222, Ad26.COV2.S, and CoronaVac).

Attitudes and Knowledge of European Medical Students and Early Graduates about Vaccination and Self-Reported Vaccination Coverage-Multinational Cross-Sectional Survey

Vaccination is one of the most useful preventive interventions in healthcare. The purpose of our study was to gain overview of the opinions, knowledge, and engagement in vaccination practices among medical students (MS) and junior doctors (JD) in Europe. The survey was distributed from March 2016 until August 2016 via the e-mail and social media of the European Medical Students' Association. In total, 1821 responses from MS and JD from 34 countries in the European region were analysed. The majority of respondents agreed that vaccines are useful (98.7%) and effective (97.2%). Although the necessity of revaccination was supported by 99.2%, only 68.0% of the respondents went through with it. Even though the potential benefit of the flu vaccination seems to be acknowledged by our participants, only 22.1% of MS and JD declared getting the flu shot every or every other season. MS and JD were in favour of specific mandatory vaccination for medical staff (86.0%) and medical students (82.7%). Furthermore, we analysed the self-reported vaccination coverage of our participants regarding 19 vaccines. Of the respondents, 89.5% claimed to provide advice about vaccination to their friends and family. In conclusion, European MS and JD have a very positive attitude towards vaccination. However, their behaviour and knowledge demonstrate certain gaps which should be further addressed in medical education.

Super-rapid race for saving lives by developing COVID-19 vaccines

The pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people and claimed thousands of lives. Starting in China, it is arguably the most precipitous global health calamity of modern times. The entire world has rocked back to fight against the disease and the COVID-19 vaccine is the prime weapon. Even though the conventional vaccine development pipeline usually takes more than a decade, the escalating daily death rates due to COVID-19 infections have resulted in the development of fast-track strategies to bring in the vaccine under a year’s time. Governments, companies, and universities have networked to pool resources and have come up with a number of vaccine candidates. Also, international consortia have emerged to address the distribution of successful candidates. Herein, we summarize these unprecedented developments in vaccine science and discuss the types of COVID-19 vaccines, their developmental strategies, and their roles as well as their limitations.

Multi-domain narrative review of vaccine hesitancy in childhood

Vaccine hesitancy, where individuals delay or refuse some or all vaccines, is a perennial problem. It undermines the success of the immunisation programmes and places the society, especially vulnerable populations such as children, at risk of contracting infectious diseases. The phenomenon has been extensively analysed based on four aspects - confidence, complacency, convenience and costs. We suggest the alternative use of a multi-dimensional framework adapted from the "Generalist Wheel of Knowledge, Understanding and Inquiry" that was developed by Prof Larry Green and Kurt Stange, to assess the multiple facilitators and barriers towards vaccine hesitancy in childhood vaccination. The framework identifies domains in the healthcare system namely the child and parent/family, the clinician, the healthcare system and policy, and the infectious disease and corresponding vaccine that influence vaccine hesitancy. This narrative review includes literature beyond those covered by the World health Organisation Global Vaccine Action Plan (WHO GVAP). It identifies emotional distress, past negative experience and misconceptions that contribute to vaccine hesitancy in children and family, while attitude and motivation underpin vaccine hesitancy in clinicians. The healthcare system contributes to vaccine hesitancy when enforcements, diligent monitoring and transparency are absent or lacking. Inefficient dissemination of information about the disease and its associated vaccine as well as inadequate surveillance of misinformation add to vaccine hesitancy. The inter-domain factors highlight the roles of relationship between the clinician, child and parent, information mastery of the clinician, prioritisation of resources and equity in combating vaccine hesitancy. Using this framework, we present evidence-based strategies which have been effective in mitigating vaccine hesitancy for each domain and their corresponding inter-domains. By providing new perspectives of a complex problem and its potential solutions, this narrative review aims to complement and support the WHO GVAP by developing a coordinated multi-domain strategy to mitigate vaccine hesitancy in childhood.

The find of COVID-19 vaccine: Challenges and opportunities

Severe acute respiratory syndrome coronavirus (SARS-CoV-2), a novel corona virus, causing COVID-19 with Flu-like symptoms is the first alarming pandemic of the third millennium. SARS-CoV-2 belongs to beta coronavirus as Middle East respiratory syndrome coronavirus (MERS-CoV). Pandemic COVID-19 owes devastating mortality and destructively exceptional consequences on Socio-Economics life around the world. Therefore, the current review is redirected to the scientific community to owe comprehensive visualization about SARS-CoV-2 to tackle the current pandemic. As systematically shown through the current review, it indexes unmet medical problem of COVID-19 in view of public health and vaccination discovery for the infectious SARS-CoV-2; it is currently under-investigational therapeutic protocols, and next possible vaccines. Furthermore, the review extensively reports the precautionary measures to achieve" COVID-19/Flatten the curve". It is concluded that vaccines formulation within exceptional no time in this pandemic is highly recommended, via following the same protocols of previous pandemics; MERS-CoV and SARS-CoV, and excluding some initial steps of vaccination development process.

Therapeutic Strategies in the Management of COVID-19

Since December 2019, SARS-CoV-2 (COVID-19), novel corona virus has caused pandemic globally, with rise in the number of cases and death of the patients. Vast majority of the countries that are dealing with rise in the active cases and death of patients suffering from novel corona viruses COVID-19 are trying to content the virus by isolating the patients and treating them with the approved antiviral that have been previously used in treating SARS, MERS, and drugs that are used to treat other viral infections. Some of these are under clinical trials. At present there are no therapeutically effective antiviral present and there are no vaccines or drugs available that are clinically approved for treating the corona virus. The current strategy is to re-purpose the available drugs or antiviral that can minimise or reduce the burden of the health care emergencies. In this article the reuse of antiviral, US-FDA approved drugs, plant based therapeutic, anti-malarial, anti-parasitic, anti-HIV drugs and the traditional medicines that are being currently used in treating the symptoms of COVID-19 patients is discussed emphasis is also given on the treatment using monoclonal antibodies. The present article provides the therapeutic strategies that will qualify as one of the best available treatment for the better management of the COVID-19 patients in order to achieve medical benefits.

A rapid review of recent advances in diagnosis, treatment and vaccination for COVID-19

COVID-19 is caused by SARS-CoV-2, which originated in Wuhan, Hubei province, Central China, in December 2019 and since then has spread rapidly, resulting in a severe pandemic. The infected patient presents with varying non-specific symptoms requiring an accurate and rapid diagnostic tool to detect SARS-CoV-2. This is followed by effective patient isolation and early treatment initiation ranging from supportive therapy to specific drugs such as corticosteroids, antiviral agents, antibiotics, and the recently introduced convalescent plasma. The development of an efficient vaccine has been an on-going challenge by various nations and research companies. A literature search was conducted in early December 2020 in all the major databases such as Medline/PubMed, Web of Science, Scopus and Google Scholar search engines. The findings are discussed in three main thematic areas namely diagnostic approaches, therapeutic options, and potential vaccines in various phases of development. Therefore, an effective and economical vaccine remains the only retort to combat COVID-19 successfully to save millions of lives during this pandemic. However, there is a great scope for further research in discovering cost-effective and safer therapeutics, vaccines and strategies to ensure equitable access to COVID-19 prevention and treatment services.

Circumsporozoite Surface Protein-based malaria vaccines: a review

Malaria represents a serious public health problem, presenting with high rates of incidence, morbidity and mortality in tropical and subtropical regions of the world. According to the World Health Organization, in 2018 there were 228 million cases and 405 thousand deaths caused by this disease in the world, affecting mainly children and pregnant women in Africa. Despite the programs carried out to control this disease, drug resistance and invertebrate vector resistance to insecticides have generated difficulties. An efficient vaccine against malaria would be a strategy with a high impact on the eradication and control of this disease. Researches aimed at developing vaccines have focused on antigens of high importance for the survival of the parasite such as the Circumsporozoite Surface Protein, involved in the pre-erythrocytic cycle during parasites invasion in hepatocytes. Currently, RTS’S is the most promising vaccine for malaria and was constructed using CSP; its performance was evaluated using two types of adjuvants: AS01 and AS02. The purpose of this review was to provide a bibliographic survey of historical researches that led to the development of RTS’S and its performance analysis over the decade. The search for new adjuvants to be associated with this antigen seems to be a way to obtain higher percentages of protection for a future malaria vaccine.

Regeneration of irradiation-damaged esophagus by local delivery of mesenchymal stem-cell spheroids encapsulated in a hyaluronic-acid-based hydrogel

Radiation therapy (RT) is a typical treatment for head and neck cancers. Generally, prolonged irradiation of the esophagus causes esophageal fibrosis due to increased reactive oxygen species and proinflammatory cytokines. This study was designed to determine whether catechol-functionalized hyaluronic acid (HA-CA) hydrogel-encapsulated human mesenchymal stem-cell spheroids (MSC-SPs) could ameliorate damage to the esophagus in a mouse model of radiation-induced esophageal fibrosis. MSC-SPs were cultured in concave microwells 600 μm in diameter at a cell density of 1 × 10⁶ cells per mL. Most cells formed spheroids with a 100-300 μm size distribution in concave microwells. MSC-SPs were well maintained in the HA gel, and live-dead staining confirmed that most cells survived. The HA gel containing the MSC-SPs was then injected into the damaged esophageal layer. Inflammatory signs or adverse tissue reactions were not observed after esophageal injection of HA-gel-encapsulated MSC-SPs. Based on Masson's trichrome staining at 4 and 12 weeks postinjection, the inner esophageal layer (IEL) was significantly thinner in the MSC-SP + HA gel group compared to those in the other experimental groups. While the saline and HA gel treatments made the esophageal muscles loose and thick, the MSC-SP + HA gel group showed bundles of tightly packed esophageal muscles, as assayed by desmin immunostaining. qPCR analysis showed that epithelial genes tended to increase over time in the MSC-SP + HA gel group, and the expression of most fibrosis-related genes decreased. This study proposes the potential of using HA-CA-hydrogel-encapsulated MSC-SPs as a promising therapy against radiation-induced esophageal fibrosis.

A COVID-19 Vaccine: Big Strides Come with Big Challenges

As of 8 January 2021, there were 86,749,940 confirmed coronavirus disease 2019 (COVID-19) cases and 1,890,342 COVID-19-related deaths worldwide, as reported by the World Health Organization (WHO). In order to address the COVID-19 pandemic by limiting transmission, an intense global effort is underway to develop a vaccine against SARS-CoV-2. The development of a safe and effective vaccine usually requires several years of pre-clinical and clinical stages of evaluation and requires strict regulatory approvals before it can be manufactured in bulk and distributed. Since the global impact of COVID-19 is unprecedented in the modern era, the development and testing of a new vaccine are being expedited. Given the high-level of attrition during vaccine development, simultaneous testing of multiple candidates increases the probability of finding one that is effective. Over 200 vaccines are currently in development, with over 60 candidate vaccines being tested in clinical trials. These make use of various platforms and are at different stages of development. This review discusses the different phases of vaccine development and the various platforms in use for candidate COVID-19 vaccines, including their progress to date. The potential challenges once a vaccine becomes available are also addressed.

Effects of aluminum chloride and coenzyme Q10 on the molecular structure of lipids and the morphology of the brain hippocampus cells

Aluminum chloride (AlCl₃) is a neurotoxic substance, while coenzyme Q10 (CoQ10) is considered a lipid antioxidant. Herein, their effects on the molecular structure of lipids and the morphology of the hippocampus brain tissue were investigated. Three groups of Wistar albino male rats were used in this study. For four weeks, one group was kept as a control group; the second group was given AlCl₃; the third group was given AlCl₃/CoQ10. Fourier transform infrared (FTIR) and histopathological examinations were utilized to estimate alterations in the molecular structure of the lipids and the cell morphology, respectively. The FTIR spectra revealed considerable decreases in the CH contents and alterations in the molecular ratios of olefinic Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> CH/ν_as(CH₃), ν_as(CH₂)/ν_as(CH₃), and ν_as(CH₂)/[ν_as(CH₂) + ν_s(CH₂)] in the group given AlCl₃. However, no significant changes were detected in those rats given AlCl₃/CoQ10. Histopathology images uncovered shrinking and dark centers in the pyramidal cells of brain tissue hippocampal cells. The diameters of the pyramidal cells were estimated to be 4.81 ± 0.55 μm, 4.04 ± 0.71 μm, and 4.63 ± 0.71 μm for the control, AlCl₃, and AlCl₃/CoQ10 groups, respectively. The study showed that the AlCl₃ could cause a shrinking of around 16% in the hippocampus pyramidal cells; besides, CoQ10 is a powerful therapeutic antioxidant to help restore the hippocampal neurons to a regular state.

Although the AlCl₃ affected the molecular structure of lipids and the morphology of the brain hippocampus cells, the CoQ10 showed a powerful therapeutic antioxidant being helped restore the hippocampal neurons to their normal state.

The 2020 race towards SARS-CoV-2 specific vaccines

The global outbreak of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlighted a requirement for two pronged clinical interventions such as development of effective vaccines and acute therapeutic options for medium-to-severe stages of "coronavirus disease 2019" (COVID-19). Effective vaccines, if successfully developed, have been emphasized to become the most effective strategy in the global fight against the COVID-19 pandemic. Basic research advances in biotechnology and genetic engineering have already provided excellent progress and groundbreaking new discoveries in the field of the coronavirus biology and its epidemiology. In particular, for the vaccine development the advances in characterization of a capsid structure and identification of its antigens that can become targets for new vaccines. The development of the experimental vaccines requires a plethora of molecular techniques as well as strict compliance with safety procedures. The research and clinical data integrity, cross-validation of the results, and appropriated studies from the perspective of efficacy and potently side effects have recently become a hotly discussed topic. In this review, we present an update on latest advances and progress in an ongoing race to develop 52 different vaccines against SARS-CoV-2. Our analysis is focused on registered clinical trials (current as of November 04, 2020) that fulfill the international safety and efficacy criteria in the vaccine development. The requirements as well as benefits and risks of diverse types of SARS-CoV-2 vaccines are discussed including those containing whole-virus and live-attenuated vaccines, subunit vaccines, mRNA vaccines, DNA vaccines, live vector vaccines, and also plant-based vaccine formulation containing coronavirus-like particle (VLP). The challenges associated with the vaccine development as well as its distribution, safety and long-term effectiveness have also been highlighted and discussed.

COVID-19 Vaccines: A Race Against Time in the Middle of Death and Devastation!

The coronavirus disease 2019 (COVID-19) has turned into a global human tragedy and economic devastation. Governments have implemented lockdown measures, blocked international travel, and enforced other public containment measures to mitigate the virus morbidity and mortality. As of today, no drug has the power to fight the infection and bring normalcy to the utter chaos. This leaves us with only one choice namely an effective and safe vaccine that shall be manufactured as soon as possible and available to all countries and populations affected by the pandemic at an affordable price. There has been an unprecedented fast track path taken in Research & Development by the World community for developing an effective and safe vaccine. Platform technology has been exploited to develop candidate vaccines in a matter of days to weeks, and as of now, 108 such vaccines are available. Six of these vaccines have entered clinical trials. As clinical trials are "rate-limiting" and "time-consuming", many innovative methods are in practice for a fast track. These include parallel phase I-II trials and obtaining efficacy data from phase IIb trials. Human "challenge experiments" to confirm efficacy in humans is under serious consideration. The availability of the COVID-19 vaccine has become a race against time in the middle of death and devastation. There is an atmosphere of tremendous hype around the COVID-19 vaccine, and developers are using every moment to make claims, which remain unverified. However, concerns are raised about a rush to deploy a COVID-19 vaccine. Applying "Quick fix" and "short cuts" can lead to errors with disastrous consequences.

COVID-19 Vaccine Frontrunners and Their Nanotechnology Design

Humanity is experiencing a catastrophic pandemic. SARS-CoV-2 has spread globally to cause significant morbidity and mortality, and there still remain unknowns about the biology and pathology of the virus. Even with testing, tracing, and social distancing, many countries are struggling to contain SARS-CoV-2. COVID-19 will only be suppressible when herd immunity develops, either because of an effective vaccine or if the population has been infected and is resistant to reinfection. There is virtually no chance of a return to pre-COVID-19 societal behavior until there is an effective vaccine. Concerted efforts by physicians, academic laboratories, and companies around the world have improved detection and treatment and made promising early steps, developing many vaccine candidates at a pace that has been unmatched for prior diseases. As of August 11, 2020, 28 of these companies have advanced into clinical trials with Moderna, CanSino, the University of Oxford, BioNTech, Sinovac, Sinopharm, Anhui Zhifei Longcom, Inovio, Novavax, Vaxine, Zydus Cadila, Institute of Medical Biology, and the Gamaleya Research Institute having moved beyond their initial safety and immunogenicity studies. This review analyzes these frontrunners in the vaccine development space and delves into their posted results while highlighting the role of the nanotechnologies applied by all the vaccine developers.