Use of adenovirus type-5 vectored vaccines: a cautionary tale

Public Discourse, User Reactions, and Conspiracy Theories on the X Platform About HIV Vaccines: Data Mining and Content Analysis

BACKGROUND

The initiation of clinical trials for messenger RNA (mRNA) HIV vaccines in early 2022 revived public discussion on HIV vaccines after 3 decades of unsuccessful research. These trials followed the success of mRNA technology in COVID-19 vaccines but unfolded amid intense vaccine debates during the COVID-19 pandemic. It is crucial to gain insights into public discourse and reactions about potential new vaccines, and social media platforms such as X (formerly known as Twitter) provide important channels.

OBJECTIVE

Drawing from infodemiology and infoveillance research, this study investigated the patterns of public discourse and message-level drivers of user reactions on X regarding HIV vaccines by analyzing posts using machine learning algorithms. We examined how users used different post types to contribute to topics and valence and how these topics and valence influenced like and repost counts. In addition, the study identified salient aspects of HIV vaccines related to COVID-19 and prominent anti-HIV vaccine conspiracy theories through manual coding.

METHODS

We collected 36,424 English-language original posts about HIV vaccines on the X platform from January 1, 2022, to December 31, 2022. We used topic modeling and sentiment analysis to uncover latent topics and valence, which were subsequently analyzed across post types in cross-tabulation analyses and integrated into linear regression models to predict user reactions, specifically likes and reposts. Furthermore, we manually coded the 1000 most engaged posts about HIV and COVID-19 to uncover salient aspects of HIV vaccines related to COVID-19 and the 1000 most engaged negative posts to identify prominent anti-HIV vaccine conspiracy theories.

RESULTS

Topic modeling revealed 3 topics: HIV and COVID-19, mRNA HIV vaccine trials, and HIV vaccine and immunity. HIV and COVID-19 underscored the connections between HIV vaccines and COVID-19 vaccines, as evidenced by subtopics about their reciprocal impact on development and various comparisons. The overall valence of the posts was marginally positive. Compared to self-composed posts initiating new conversations, there was a higher proportion of HIV and COVID-19-related and negative posts among quote posts and replies, which contribute to existing conversations. The topic of mRNA HIV vaccine trials, most evident in self-composed posts, increased repost counts. Positive valence increased like and repost counts. Prominent anti-HIV vaccine conspiracy theories often falsely linked HIV vaccines to concurrent COVID-19 and other HIV-related events.

CONCLUSIONS

The results highlight COVID-19 as a significant context for public discourse and reactions regarding HIV vaccines from both positive and negative perspectives. The success of mRNA COVID-19 vaccines shed a positive light on HIV vaccines. However, COVID-19 also situated HIV vaccines in a negative context, as observed in some anti-HIV vaccine conspiracy theories misleadingly connecting HIV vaccines with COVID-19. These findings have implications for public health communication strategies concerning HIV vaccines.

COVID-19 vaccines: history of the pandemic's great scientific success and flawed policy implementation

The COVID-19 vaccine has been a miraculous, life-saving advance, offering staggering efficacy in adults, and was developed with astonishing speed. The time from sequencing the virus to authorizing the first COVID-19 vaccine was so brisk even the optimists appear close-minded. Yet, simultaneously, United States' COVID-19 vaccination roll-out and related policies have contained missed opportunities, errors, run counter to evidence-based medicine, and revealed limitations in the judgment of public policymakers. Misplaced utilization, contradictory messaging, and poor deployment in those who would benefit most-the elderly and high-risk-alongside unrealistic messaging, exaggeration, and coercion in those who benefit least-young, healthy Americans-is at the heart. It is important to consider the history of COVID-19 vaccines to identify where we succeeded and where we failed, and the effects that these errors may have more broadly on vaccination hesitancy and routine childhood immunization programs in the decades to come.

Vaccine Strategies to Elicit Mucosal Immunity

Vaccines are essential tools to prevent infection and control transmission of infectious diseases that threaten public health. Most infectious agents enter their hosts across mucosal surfaces, which make up key first lines of host defense against pathogens. Mucosal immune responses play critical roles in host immune defense to provide durable and better recall responses. Substantial attention has been focused on developing effective mucosal vaccines to elicit robust localized and systemic immune responses by administration via mucosal routes. Mucosal vaccines that elicit effective immune responses yield protection superior to parenterally delivered vaccines. Beyond their valuable immunogenicity, mucosal vaccines can be less expensive and easier to administer without a need for injection materials and more highly trained personnel. However, developing effective mucosal vaccines faces many challenges, and much effort has been directed at their development. In this article, we review the history of mucosal vaccine development and present an overview of mucosal compartment biology and the roles that mucosal immunity plays in defending against infection, knowledge that has helped inform mucosal vaccine development. We explore new progress in mucosal vaccine design and optimization and novel approaches created to improve the efficacy and safety of mucosal vaccines.

Therapeutic Challenges in COVID-19

SARS-CoV2 is a novel respiratory coronavirus and, understanding its molecular mechanism is a prerequisite to developing effective treatment for COVID-19. This RNA genome-carrying virus has a protein coat with spikes (S) that attaches to the ACE2 receptor at the cell surface of human cells. Several repurposed drugs are used to treat COVID-19 patients that are proven to be largely unsuccessful or have limited success in reducing mortalities. Several vaccines are in use to reduce the viral load to prevent developing symptoms. Major challenges to their efficacy include the inability of antibody molecules to enter cells but remain effective in the bloodstream to kill the virus. The efficacy of vaccines also depends on their neutralizing ability to constantly evolve new virus strains due to novel mutations and evolutionary survival dynamics. Taken together, SARS-CoV2 antibody vaccines may not be very effective and other approaches based on genetic, genomic, and protein interactome could be fruitful to identify therapeutic targets to reduce disease-related mortalities.

Comparative Analysis of Primary and Monovalent Booster SARS-CoV-2 Vaccination Coverage in Adults with and without HIV in Catalonia, Spain

People with HIV (PWH) may be more susceptible to SARS-CoV-2 infection and worse clinical outcomes. We investigated the disparity in SARS-CoV-2 vaccination coverage between PWH and those without HIV (PWoH) in Catalonia, Spain, assessing primary and monovalent booster vaccination coverage from December 2021 to July 2022. The vaccines administered were BNT162, ChAdOx1-S, mRNA-127, and Ad26.COV2.S. Using a 1:10 ratio of PWH to PWoH based on sex, age, and socioeconomic deprivation, the analysis included 201,630 individuals (183,300 PWoH and 18,330 PWH). Despite a higher prevalence of comorbidities, PWH exhibited lower rates of complete primary vaccination (78.2% vs. 81.8%, p < 0.001) but surpassed PWoH in booster coverage (68.5% vs. 63.1%, p < 0.001). Notably, complete vaccination rates were lower among PWH with CD4 <200 cells/μL, detectable HIV viremia, and migrants compared to PWoH (p < 0.001, all). However, PWH with CD4 < 200 cells/μL received more boosters (p < 0.001). In multivariable logistic regression analysis of the overall population, a prior SARS-CoV-2 diagnosis, HIV status, migrants, and mild-to-severe socioeconomic deprivation were associated with lower primary vaccination coverage, reflecting barriers to healthcare and vaccine access. However, booster vaccination was higher among PWH. Targeted interventions are needed to improve vaccine coverage and address hesitancy in vulnerable populations.

Purposing plant-derived exosomes-like nanovesicles for drug delivery: patents and literature review

INTRODUCTION

How can biotechnology and organic agriculture be fused and promoted simultaneously to overcome the main challenges in drug delivery systems, improving the quality of the care provided, [1] patient outcomes, and [2] reducing the side effects of most of the current treatments? Unfortunately, the role of organic agriculture in future human health treatment still represents a binary organic-conventional question, a debate perpetuating an either/or mentality. However, extracellular exosomes-like nanoparticles define a new organic path that plants and vegetables can release. In this review, we concisely propose plant-derived exosome-like nanovesicles and discuss their most important biological and pharmacological roles, representing a new tool for drug delivery.

AREAS COVERED

plant-derived exosomes-like nanovesicles; nature farming; green manufacturing practice; drug delivery; organic agriculture.

EXPERT OPINION

There is growing interest in the potential use of plant-derived exosomes-like nanovesicles for various diagnostic and therapeutic applications that should translate into a supplement to current nano-pharmaceuticals. Despite their clinical potential, the lack of sensitive preparatory and analytical technologies for plant-derived exosomes-like nanovesicles poses a barrier to clinical translation. An increasing number of articles are recently published on new analytical platforms to address these challenges in cross-comparison with conventional assay methods. This review also mentions two patents from ExoLab-Italia on plant-derived exosome-like nanovesicles, respectively, on plant-derived exosome-like nanovesicles' ability to naturally deliver a series of potentially therapeutic molecules and a novel approach to upload them with therapeutic molecules.

HIV and COVID-19 Disease

Despite effective antiretroviral therapy (ART), HIV infected individuals throughout the world remain at significant risk of respiratory infections and non-communicable disease. Severe disease from SARS-CoV-2 is associated with a hyperinflammatory phenotype which manifests in the lungs as pneumonia and in some cases can lead to acute respiratory failure. Progression to severe COVID-19 is associated with comorbid disease such as obesity, diabetes mellitus and cardiovascular disease, however data concerning the associated risks of HIV coinfection are still conflicting, with large population studies demonstrating poorer outcomes, whilst smaller, case-controlled studies showing better outcomes. Furthermore, underlying immunopathological processes within the lungs and elsewhere, including interactions with other opportunistic infections (OI), remain largely undefined. Nonetheless, new and repurposed anti-viral therapies and vaccines which have been developed are safe to use in this population, and anti-inflammatory agents are recommended with the caveat that the coexistence of opportunistic infections is considered and excluded. Finally, HIV infected patients remain reliant on good ART adherence practices to maintain HIV viral suppression, and some of these practices were disrupted during the COVID-19 pandemic, putting these patients at further risk for acute and long-term adverse outcomes.

Adenovirus vector and mRNA vaccines: Mechanisms regulating their immunogenicity

Replication-incompetent adenovirus (Ad) vector and mRNA-lipid nanoparticle (LNP) constructs represent two modular vaccine platforms that have attracted substantial interest over the past two decades. Due to the COVID-19 pandemic and the rapid development of multiple successful vaccines based on these technologies, there is now clear real-world evidence of the utility and efficacy of these platforms. Considerable optimization and refinement efforts underpin the successful application of these technologies. Despite this, our understanding of the specific pathways and processes engaged by these vaccines to stimulate the immune response remains incomplete. This review will synthesize our current knowledge of the specific mechanisms by which CD8⁺ T cell and antibody responses are induced by each of these vaccine platforms, and how this can be impacted by specific vaccine construction techniques. Key gaps in our knowledge are also highlighted, which can hopefully focus future studies.

Current clinical status of new COVID-19 vaccines and immunotherapy

COVID-19, caused by SARS-CoV-2, is a positive-strand RNA belonging to Coronaviridae family, along with MERS and SARS. Since its first report in 2019 in Wuhan, China, it has affected over 530 million people and led to 6.3 million deaths worldwide until June 2022. Despite eleven vaccines being used worldwide already, new variants are of concern. Therefore, the governing bodies are re-evaluating the strategies for achieving universal vaccination. Initially, the WHO expected that vaccines showing around 50-80% efficacy would develop in 1-2 years. However, US-FDA announced emergency approval of the two m-RNA vaccines within 11 months of vaccine development, which enabled early vaccination for healthcare workers in many countries. Later, in January 2021, 63 vaccine candidates were under human clinical trials and 172 under preclinical development. Currently, the number of such clinical studies is still increasing. In this review, we have summarized the updates on the clinical status of the COVID-19 and the available treatments. Additionally, COVID-19 had created negative impacts on world's economy; affected agriculture, industries, and tourism service sectors; and majorly affected low-income countries. The review discusses the clinical outcomes, latest statistics, socio-economic impacts of pandemic and treatment approaches against SARS-CoV-2, and strategies against the new variant of concern. The review will help understand the current status of vaccines and other therapies while also providing insights about upcoming vaccines and therapies for COVID-19 management.

In silico design of refined ferritin-SARS-CoV-2 glyco-RBD nanoparticle vaccine

With the onset of Coronavirus disease 2019 (COVID-19) pandemic, all attention was drawn to finding solutions to cure the coronavirus disease. Among all vaccination strategies, the nanoparticle vaccine has been shown to stimulate the immune system and provide optimal immunity to the virus in a single dose. Ferritin is a reliable self-assembled nanoparticle platform for vaccine production that has already been used in experimental studies. Furthermore, glycosylation plays a crucial role in the design of antibodies and vaccines and is an essential element in developing effective subunit vaccines. In this computational study, ferritin nanoparticles and glycosylation, which are two unique facets of vaccine design, were used to model improved nanoparticle vaccines for the first time. In this regard, molecular modeling and molecular dynamics simulation were carried out to construct three atomistic models of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (RBD)-ferritin nanoparticle vaccine, including unglycosylated, glycosylated, and modified with additional O-glycans at the ferritin–RBD interface. It was shown that the ferritin–RBD complex becomes more stable when glycans are added to the ferritin–RBD interface and optimal performance of this nanoparticle can be achieved. If validated experimentally, these findings could improve the design of nanoparticles against all microbial infections.

mRNA- and Adenovirus-Based Vaccines against SARS-CoV-2 in HIV-Positive People

About two years have passed since the identification of SARS-CoV-2 in China. The rapid spread of this virus all over the world and its high transmissibility and pathogenicity in humans have resulted in a global pandemic. The negative impact of COVID-19 on health, society and the economy at the global level has pushed researchers and pharmaceutical companies to develop effective vaccines to fight SARS-CoV-2. Thanks to this collaborative effort, the first COVID-19 vaccine was developed in less than a year. Since then, several COVID-19 vaccines have been validated for use by the World Health Organization. Among these, mRNA- (BNT162b2 and mRNA1273) and adenovirus-based (ChAdOx1) vaccines were developed through the use of novel technologies. While all three of these vaccines have shown effectiveness against the COVID-19 disease and their immunogenicity was characterized in clinical trials in the general population, data on their efficacy and immunogenicity in people living with HIV (PLWH) are limited. In this review, we provide a description of the characteristics of mRNA- and adenovirus-based vaccines and of the immune response elicited in the general population by vaccination. Then we describe the use of these vaccines and their efficacy and immunogenicity in people living with HIV and we conclude with a discussion regarding some open questions concerning the use of mRNA- and adenovirus-based COVID-19 vaccines in PLWH.

Safety and Efficacy of the Common Vaccines against COVID-19

The worldwide pandemic of coronavirus disease 2019 (COVID-19) has imposed a challenge on human health worldwide, and vaccination represents a vital strategy to control the pandemic. To date, multiple COVID-19 vaccines have been granted emergency use authorization, including inactivated vaccines, adenovirus-vectored vaccines, and nucleic acid vaccines. These vaccines have different technical principles, which will necessarily lead to differences in safety and efficacy. Therefore, we aim to implement a systematic review by synthesizing clinical experimental data combined with mass vaccination data and conducting a synthesis to evaluate the safety and efficacy of COVID-19 vaccines. Compared with other vaccines, adverse reactions after vaccination with inactivated vaccines are relatively low. The efficacy of inactivated vaccines is approximately 60%, adenovirus-vectored vaccines are 65%, and mRNA vaccines are 90%, which are always efficient against asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, symptomatic COVID-19, COVID-19 hospitalization, severe or critical hospitalization, and death. RNA-based vaccines have a number of advantages and are one of the most promising vaccines identified to date and are particularly important during a pandemic. However, further improvements are required. In time, all the antibody levels weaken gradually, so a booster dose is needed to maintain immunity. Compared with homologous prime-boost immunization, heterologous prime-boost immunization prompts more robust humoral and cellular immune responses.

HIV and SARS-CoV-2 Co-infection: Epidemiological, Clinical Features, and Future Implications for Clinical Care and Public Health for People Living with HIV (PLWH) and HIV Most-at-Risk Groups

Purpose of Review

The purpose of this review is to use the currently available clinical and epidemiological data, to identify key aspects to improve both the clinical management and public health response to SARS-CoV-2/HIV co-infection among HIV vulnerable populations and people living with HIV (PLWH).

Recent Findings

While at the beginning of the COVID-19 pandemic, the lack of robust information on SARS-CoV-2/HIV co-infection, prevented a clear picture of the synergies between them, currently available data strongly support the importance of common structural factors on both the acquisition and clinical impact of these infections and the relevance of age, comorbidities, and detectable HIV viral load as associated worse prognostic factors among PLWH.

Summary

Although more information is needed to better understand the biological, clinical, and epidemiological relationship between both infections, a syndemic approach to prevent SARS-CoV-2 among HIV high-risk groups and PLWH, targeting these populations for SARS-CoV-2 vaccines and protocolizing early identification of PLWH with worse COVID-19 prognosis factors, is crucial strategies to decrease the overall impact of SARS-CoV-2 /HIV co-infection.

Evolution of drug delivery systems: From 1950 to 2020 and beyond

Modern drug delivery technology began in 1952 with the advent of the Spansule® sustained-release capsule technology, which can deliver a drug for 12 h after oral administration through an initial immediate dose followed by the remaining released gradually. Until the 1980s, oral and transdermal formulations providing therapeutic durations up to 24 h for small molecules dominated the drug delivery field and the market. The introduction of Lupron Depot® in 1989 opened the door for long-acting injectables and implantables, extending the drug delivery duration from days to months and occasionally years. Notably, the new technologies allowed long-term delivery of peptide and protein drugs, although limited to parenteral administration. The introduction of the first PEGylated protein, Adagen®, in 1990 marked the new era of PEGylation, resulting in Doxil® (doxorubicin in PEGylated liposome) in 1995, Movantik® (PEGylated naloxone - naloxegol) in 2014, and Onpattro® (Patisiran - siRNA in PEGylated lipid nanoparticle) in 2018. Drug-polymer complexes were introduced, e.g., InFed® (iron-dextran complex injection) in 1974 and Abraxane® (paclitaxel-albumin complex) in 2005. In 2000, both Mylotarg™ (antibody-drug conjugate - gemtuzumab ozogamicin) and Rapamune® (sirolimus nanocrystal formulation) were introduced. The year 2000 also marked the launching of the National Nanotechnology Initiative by the U.S. government, which was soon followed by the rest of the world. Extensive work on nanomedicine, particularly formulations designed to escape from endosomes after being taken by tumor cells, along with PEGylation technology, ultimately resulted in the timely development of lipid nanoparticle formulations for COVID-19 vaccine delivery in 2020. While the advances in drug delivery technologies for the last seven decades are breathtaking, they are only the tip of an iceberg of technologies that have yet to be utilized in an approved formulation or even to be discovered. As life expectancy continues to increase, more people require long-term care for various diseases. Filling the current and future unmet needs requires innovative drug delivery technologies to overcome age-old familiar hurdles, e.g., improving water-solubility of poorly soluble drugs, overcoming biological barriers, and developing more efficient long-acting depot formulations. The lessons learned from the past are essential assets for developing future drug delivery technologies implemented into products. As the development of COVID-19 vaccines demonstrated, meeting the unforeseen crisis of the uncertain future requires continuous cumulation of failures (as learning experiences), knowledge, and technologies. Conscious efforts of supporting diversified research topics in the drug delivery field are urgently needed more than ever.

COVID-19 vaccines for high risk and immunocompromised patients

The availability of multiple versions of vaccines designed to help prevent COVID-19 has offered an opportunity to at least control the current pandemic, and possibly to quickly eradicate this disease fully, along with the implementation of other preventive measures. In order to accomplish this feat more effectively, as many people as possible need to be vaccinated, especially for high-risk groups having co-morbid conditions such as diabetes, obesity and old age, and possibly those with various forms of immunodeficiencies, such as HIV/AIDS. This chapter focuses primarily on some of the basic biomedical aspects on vaccine design and use, and any possible concerns that need to be considered in getting people in the high-risk category vaccinated and monitored thereafter for their continuous health and well-being.

Adenovirus-based vaccines - a platform for pandemic preparedness against emerging viral pathogens

Zoonotic viruses continually pose a pandemic threat. Infection of humans with viruses for which we typically have little or no prior immunity can result in epidemics with high morbidity and mortality. These epidemics can have public health and economic impact and can exacerbate civil unrest or political instability. Changes in human behavior in the past few decades—increased global travel, farming intensification, the exotic animal trade, and the impact of global warming on animal migratory patterns, habitats, and ecosystems—contribute to the increased frequency of cross-species transmission events. Investing in the pre-clinical advancement of vaccine candidates against diverse emerging viral threats is crucial for pandemic preparedness. Replication-defective adenoviral (Ad) vectors have demonstrated their utility as an outbreak-responsive vaccine platform during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Ad vectors are easy to engineer; are amenable to rapid, inexpensive manufacturing; are relatively safe and immunogenic in humans; and, importantly, do not require specialized cold-chain storage, making them an ideal platform for equitable global distribution or stockpiling. In this review, we discuss the progress in applying Ad-based vaccines against emerging viruses and summarize their global safety profile, as reflected by their widespread geographic use during the SARS-CoV-2 pandemic.

HIV and SARS-CoV-2 Co-infection: Epidemiological, Clinical Features, and Future Implications for Clinical Care and Public Health for People Living with HIV (PLWH) and HIV Most-at-Risk Groups

PURPOSE OF REVIEW

The purpose of this review is using the currently available clinical and epidemiological data, to identify key aspects to improve both the clinical management and public health response with regard SARS-CoV-2/HIV co-infection among HIV vulnerable populations and people living with HIV (PLWH).

RECENT FINDINGS

While at the beginning of the COVID-19 pandemic, the lack of robust information on SARS-CoV-2/HIV coinfection prevented to have a clear picture of the synergies between them, currently available data strongly supports the importance of common structural factors on both the acquisition and clinical impact of these infections and the relevance of age, co-morbidities, and HIV viral load as associated worse prognosis factors among PLWH. Although more information is needed to better understand the biological, clinical, and epidemiological relationship between both infections, in the meanwhile, syndemic approaches to prevent SARS-CoV-2 among HIV higher risk groups and PLWH, targeting these population for SARS-CoV-2 vaccines and protocolizing early identification of HIV + patients with worse COVID-19 prognosis factors, are crucial strategies to decrease the overall impact of SARS-CoV-2 /HIV coinfection.

Impact of Chronic HIV Infection on SARS-CoV-2 Infection, COVID-19 Disease and Vaccines

Purpose of Review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has developed into a global pandemic that affect the health of hundreds of millions worldwide. In particular, SARS-CoV-2 infection in people with chronic human immune deficiency virus (HIV) infection is of concern, due to their already immunocompromised status. Yet, whether and how the immunological changes brought about by HIV will affect the immune responses against SARS-CoV-2 acute infection and impact the effectiveness of vaccines remain unclear. We discuss the intersection of COVID-19 in HIV-infected individuals.

Recent Findings

People living with HIV (PLWH) may be at increased risk of severe SARS-CoV-2 mediated disease complication due to functional impairment of the immune system and persistent inflammation, which can be ameliorated by antiretroviral therapy. Importantly, limited data suggest that current approved vaccines may be safe and efficacious in PLWH.

Summary

To address remaining questions and supplement limited experimental evidence, more studies examining the interplay between HIV and SARS-CoV-2 through their impact on the host immune system are required.

The glycosylation in SARS-CoV-2 and its receptor ACE2

Coronavirus disease 2019 (COVID-19), a highly infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 235 million individuals and led to more than 4.8 million deaths worldwide as of October 5 2021. Cryo-electron microscopy and topology show that the SARS-CoV-2 genome encodes lots of highly glycosylated proteins, such as spike (S), envelope (E), membrane (M), and ORF3a proteins, which are responsible for host recognition, penetration, binding, recycling and pathogenesis. Here we reviewed the detections, substrates, biological functions of the glycosylation in SARS-CoV-2 proteins as well as the human receptor ACE2, and also summarized the approved and undergoing SARS-CoV-2 therapeutics associated with glycosylation. This review may not only broad the understanding of viral glycobiology, but also provide key clues for the development of new preventive and therapeutic methodologies against SARS-CoV-2 and its variants.

National strategies for vaccination against COVID-19 in people living with HIV in Central and Eastern European region

Introduction

People living with HIV (PLWH) are at higher risk of poorer COVID‐19 outcomes. Vaccination is a safe and effective method of prevention against many infectious diseases, including COVID‐19. Here we investigate the strategies for national COVID‐19 vaccination programmes across central and eastern Europe and the inclusion of PLWH in vaccination programmes.

Methods

The Euroguidelines in Central and Eastern Europe Network Group consists of experts in the field of infectious diseases from 24 countries in the region. Between 1 November 2020 and 19 March 2021 the group proceeded an on‐line survey consisting of 20 questions.

Results

Twenty‐two countries (out of 24 invited) participated in the survey and 20/22 countries in the period between December 2020 and March 2021 had already started their COVID‐19 vaccination programme. In total, seven different vaccines were used by participating countries. In 17/21 countries (81%), vaccinated persons were centralized within the national registry. In 8/21 countries (38%) PLWH were prioritized for vaccination (the Czech Republic, Greece, Hungary, Lithuania, Montenegro, Romania, Slovakia, Slovenia) and the Czech Republic, Greece and Serbia had put in place national guidelines for vaccination of PLWH. In 14/20 countries (70%) vaccination was only provided by designated centres. Eighteen respondents (18/21; 85.7%) reported that they planned to follow up HIV patients vaccinated against COVID‐19, mainly by measuring antibody levels and checking COVID‐19 incidence (11/21; 52.3%).

Conclusions

This survey‐based study suggests that there are significant differences in terms of prioritizing PLWH, the types of vaccines used, vaccination coverage, and the development and implementation of a vaccination programmes within the region. Regardless of heterogenicity and existing barriers within the region, systematic vaccination in PLWH should have the highest priority, especially in those with severe immunodeficiency, risk factors, and in the elderly, aiming for prompt and high vaccination coverage.

Controversy surrounding the Sputnik V vaccine

The Sputnik V COVID-19 vaccine is a member of the so-called vector vaccines and uses two different vectors (Ad26 priming and Ad5 boost) to reduce the risk of a reduction in the effectiveness of the vaccination. Real life data indicate an efficacy of the vaccine above 97%. Low cost and no need for ultra-cold storage temperature temperatures are other pluses of the Sputnik V vaccine. However, there are also several important shortcomings that must be considered such as the possible reduction of its immunogenicity in the presence of very high Ad5 neutralizing antibody titres and the decrease with age of the antibody titres neutralizing the virus. Furthermore, there is emerging documentation that Sputnik V has a reduced neutralizing capacity against the Beta variant and all variants with the spike protein carrying the E484K substitution. Nevertheless, due to its characteristics, Sputnik V could be another useful means of satisfying the need for mass vaccination. However, it is imperative to document the efficacy and safety of the Sputnik V vaccine in individuals with high pre-existing anti-Ad26 and Ad5-neutralizing antibody titres and in those under the age of 18 or older than 60 years and be certain that Sputnik V does not cause the rare development of immune thrombotic thrombocytopenia. It is hoped that the now widespread use of this vaccine will generate a large pragmatic real-world study with data accessible to anyone interested in verifying them.

COVID-19 Vaccines for HIV-Infected Patients

Nearly 40 years have passed since the initial cases of infection with the human mmunodeficiency virus (HIV) were identified as a new disease entity and the cause of acquired immunodeficiency disease (AIDS). This virus, unlike any other, is capable of causing severe suppression of our adaptive immune defense mechanisms by directly infecting and destroying helper T cells leading to increased susceptibility to a wide variety of microbial pathogens, especially those considered to be intracellular or opportunistic. After T cells are infected, HIV reproduces itself via a somewhat unique mechanism involving various metabolic steps, which includes the use of a reverse transcriptase enzyme that enables the viral RNA to produce copies of its complementary DNA. Subsequent physiologic steps lead to the production of new virus progeny and the eventual death of the invaded T cell. Fortunately, both serologic and molecular tests (such as PCR) can be used to confirm the diagnosis of an HIV infection. In the wake of the current COVID-19 pandemic, it appears that people living with HIV/AIDS are equally or slightly more susceptible to the etiologic agent, SARS-CoV-2, than the general population having intact immune systems, but they may have more serious outcomes. Limited clinical trials have also shown that the currently available COVID-19 vaccines are both safe and effective in affording protection to HIV/AIDS patients. In this review, we further explore the unique dynamic of HIV/AIDS in the context of the worldwide COVID-19 pandemic and the implementation of vaccines as a protective measure against COVID-19, as well as what immune parameters and safeguards should be monitored in this immunocompromised group following vaccination.

Shooting at a Moving Target-Effectiveness and Emerging Challenges for SARS-CoV-2 Vaccine Development

Since late 2019 the newly emerged pandemic SARS-CoV-2, the causative agent of COVID-19, has hit the world with recurring waves of infections necessitating the global implementation of non-pharmaceutical interventions, including strict social distancing rules, the wearing of masks and the isolation of infected individuals in order to restrict virus transmissions and prevent the breakdown of our healthcare systems. These measures are not only challenging on an economic level but also have a strong impact on social lifestyles. Using traditional and novel technologies, highly efficient vaccines against SARS-CoV-2 were developed and underwent rapid clinical evaluation and approval to accelerate the immunization of the world population, aiming to end the pandemic and return to normality. However, the emergence of virus variants with improved transmission, enhanced fitness and partial immune escape from the first generation of vaccines poses new challenges, which are currently being addressed by scientists and pharmaceutical companies all over the world. In this ongoing pandemic, the evaluation of SARS-CoV-2 vaccines underlies diverse unpredictable dynamics, posed by the first broad application of the mRNA vaccine technology and their compliance, the occurrence of unexpected side effects and the rapid emergence of variations in the viral antigen. However, despite these hurdles, we conclude that the available SARS-CoV-2 vaccines are very safe and efficiently protect from severe COVID-19 and are thereby the most powerful tools to prevent further harm to our healthcare systems, economics and individual lives. This review summarizes the unprecedented pathways of vaccine development and approval during the ongoing SARS-CoV-2 pandemic. We focus on the real-world effectiveness and unexpected positive and negative side effects of the available vaccines and summarize the timeline of the applied adaptations to the recommended vaccination strategies in the light of emerging virus variants. Finally, we highlight upcoming strategies to improve the next generations of SARS-CoV-2 vaccines.

Dual-Antigen COVID-19 Vaccine Subcutaneous Prime Delivery With Oral Boosts Protects NHP Against SARS-CoV-2 Challenge

We have developed a dual-antigen COVID-19 vaccine incorporating genes for a modified SARS-CoV-2 spike protein (S-Fusion) and the viral nucleocapsid (N) protein with an Enhanced T-cell Stimulation Domain (N-ETSD) to increase the potential for MHC class II responses. The vaccine antigens are delivered by a human adenovirus serotype 5 platform, hAd5 [E1-, E2b-, E3-], previously demonstrated to be effective in the presence of Ad immunity. Vaccination of rhesus macaques with the hAd5 S-Fusion + N-ETSD vaccine by subcutaneous prime injection followed by two oral boosts elicited neutralizing anti-S IgG and T helper cell 1-biased T-cell responses to both S and N that protected the upper and lower respiratory tracts from high titer (1 x 106 TCID50) SARS-CoV-2 challenge. Notably, viral replication was inhibited within 24 hours of challenge in both lung and nasal passages, becoming undetectable within 7 days post-challenge.

A Summary of the SARS-CoV-2 Vaccines and Technologies Available or under Development

Since the beginning of 2020, the world has been in a race to develop vaccines that can control the COVID-19 pandemic. More than 250 projects have been initiated for this purpose, but only 14 of them have been authorized for use, despite being in phase 3 clinical trials. More than 40 other vaccines are also in phase 1/2 clinical trials and show promising outcomes. Regarding the appropriate choice of vaccines for each country or region, we reviewed the currently used vaccines in light of the different influencing parameters. These factors include the mode of action, dosage protocol, age group of the vaccinee, side effects, storage conditions, mounted immune response, and cost. Technically, there are seven types of vaccines developed against SARS-CoV-2: messenger RNA (mRNA), nonreplicating and replicating vectors, inactivated viruses, protein subunits, viral-like particles, DNA vaccines, and live attenuated vaccines. The mRNA type is being used for the first time in humans. Unfortunately, mutated variants of SARS-CoV-2 have started to appear worldwide, and researchers are investigating the effects of the currently used vaccines on them. There are many concerns regarding the long-term protection afforded by these vaccines and their side effects, and whether they require future modifications to be effective against the mutated variants. The development of new vaccines using more advanced technology is paramount for overcoming the difficulties in controlling the COVID-19 pandemic across the world.

Severe Acute Respiratory Syndrome Coronavirus 2 Vaccines and Cutaneous Adverse Reactions: A Review

We are entering a new stage of the severe acute respiratory syndrome coronavirus 2 pandemic with the initiation of large-scale vaccination programs globally. In these circumstances, even rare adverse effects of vaccines may be encountered more often, if millions of people are to be vaccinated in a short period. Vaccination has the potential for causing cutaneous adverse effects. Thus, it is paramount that dermatologists worldwide are acquainted with the possible skin reaction patterns to the coming vaccines. Herein, we conduct a review to discuss the most frequent cutaneous adverse effects of vaccines and their management, with a particular focus on the expected adverse reactions for the coming severe acute respiratory syndrome coronavirus 2 vaccines, such as local reactions, as well as immediate- and delayed-type hypersensitivity reactions, including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrosis, serum sickness-like reactions, and vasculitides. We also discuss the yet unanswered questions on vaccines for which we may soon be asked to provide an expert opinion.

COVID-19 vaccines for low- and middle-income countries

The COVID-19 pandemic is the biggest threat to public health in a century. Through hard work and ingenuity, scientists have developed a number of safe and effective vaccines against COVID-19 disease. However, demand far outstrips supply and countries around the world are competing for available vaccines. This review describes how low- and middle-income countries access COVID-19 vaccines, what is being done to distribute vaccines fairly, as well as the challenges ahead.

Overview of SARS-CoV-2 infection in adults living with HIV

Around 2·5 million deaths and more than 110 million COVID-19 cases have been reported globally. Although it initially appeared that HIV infection was not a risk factor for COVID-19 or more severe disease, more recent large studies suggest that people living with HIV (particularly with low CD4 cell counts or untreated HIV infection) might have a more severe clinical course than those who are HIV-negative. Moreover, the COVID-19 pandemic has disrupted HIV prevention and treatment services worldwide, creating huge challenges to the continuity of essential activities. We have reviewed the most relevant features of COVID-19 in people living with HIV and highlighted topics where further research is required.

Developmental Landscape of Potential Vaccine Candidates Based on Viral Vector for Prophylaxis of COVID-19

Severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, arose at the end of 2019 as a zoonotic virus, which is the causative agent of the novel coronavirus outbreak COVID-19. Without any clear indications of abatement, the disease has become a major healthcare threat across the globe, owing to prolonged incubation period, high prevalence, and absence of existing drugs or vaccines. Development of COVID-19 vaccine is being considered as the most efficient strategy to curtail the ongoing pandemic. Following publication of genetic sequence of SARS-CoV-2, globally extensive research and development work has been in progress to develop a vaccine against the disease. The use of genetic engineering, recombinant technologies, and other computational tools has led to the expansion of several promising vaccine candidates. The range of technology platforms being evaluated, including virus-like particles, peptides, nucleic acid (DNA and RNA), recombinant proteins, inactivated virus, live attenuated viruses, and viral vectors (replicating and non-replicating) approaches, are striking features of the vaccine development strategies. Viral vectors, the next-generation vaccine platforms, provide a convenient method for delivering vaccine antigens into the host cell to induce antigenic proteins which can be tailored to arouse an assortment of immune responses, as evident from the success of smallpox vaccine and Ervebo vaccine against Ebola virus. As per the World Health Organization, till January 22, 2021, 14 viral vector vaccine candidates are under clinical development including 10 nonreplicating and four replicating types. Moreover, another 39 candidates based on viral vector platform are under preclinical evaluation. This review will outline the current developmental landscape and discuss issues that remain critical to the success or failure of viral vector vaccine candidates against COVID-19.

COVID-19 immunity and vaccines: what a pharmacist needs to know

COVID-19 vaccines are being produced using different platforms by different companies, some of which are entering Phase 3 and 4 trials. Due to the pandemic, this production has been accelerated, which leaves a window for speculation on the method of production and safety. Pharmacists are familiar with vaccination; however, COVID-19 vaccines are still new and further work is needed to clarify many aspects, including side effects, methods of storage, and number of doses. Prioritization of vaccination has been implemented to a certain extent, but no clear strategy is available. A comprehensive overview on immunity and immunological principles for the design of COVID-19 vaccine strategies is provided in this narrative review and the current COVID-19 vaccine landscape is discussed, in addition to exploring the principles for prioritization of vaccination using data from articles available in PubMed and from health organizations. Pharmacists should have a better understanding of COVID-19 vaccines and their manufacture. This would also allow better counseling of the public on COVID 19, immunization, and explaining prioritization basis and vaccination programs.

Vaccines for COVID-19: learning from ten phase II trials to inform clinical and public health vaccination programmes

Public health professionals and clinicians, in many countries, are immersed in the ongoing and upcoming vaccination programmes for COVID-19. Published information from vaccine trials is complex. There are important and helpful insights about the nature of the available and forthcoming vaccines, immune responses and side-effects from phase II trials. We have systematically summarised information from 10 such trials on the nature of the vaccines, exclusions from the trials, immunological effects and side-effects. Some important information within these trial reports is not available in the phase III trial articles, so a complete picture requires examination of phase II and phase III trials for each vaccine. We recommend our systematic approach for the examination of other upcoming COVID-19 vaccine phase II and III trials.

Immunogenicity of clinically relevant SARS-CoV-2 vaccines in nonhuman primates and humans

Multiple preventive vaccines are being developed to counter the coronavirus disease 2019 pandemic. The leading candidates have now been evaluated in nonhuman primates (NHPs) and human phase 1 and/or phase 2 clinical trials. Several vaccines have already advanced into phase 3 efficacy trials, while others will do so before the end of 2020. Here, we summarize what is known of the antibody and T cell immunogenicity of these vaccines in NHPs and humans. To the extent possible, we compare how the vaccines have performed, taking into account the use of different assays to assess immunogenicity and inconsistencies in how the resulting data are presented. We also review the outcome of challenge experiments with severe acute respiratory syndrome coronavirus 2 in immunized macaques, while noting variations in the protocols used, including but not limited to the virus challenge doses. Press releases on the outcomes of vaccine efficacy trials are also summarized.

The Case for the Development of a Chagas Disease Vaccine: Why? How? When?

Chagas disease is a major neglected tropical disease, transmitted predominantly by triatomine insect vectors, but also through congenital and oral routes. While endemic in the Americas, it has turned into a global disease. Because of the current drug treatment limitations, a vaccine would represent a major advancement for better control of the disease. Here, we review some of the rationale, advances, and challenges for the ongoing development of a vaccine against Chagas disease. Recent pre-clinical studies in murine models have further expanded (i) the range of vaccine platforms and formulations tested; (ii) our understanding of the immune correlates for protection; and (iii) the extent of vaccine effects on cardiac function, beyond survival and parasite burden. We further discuss outstanding issues and opportunities to move Chagas disease development forward in the near future.

New Technologies for Influenza Vaccines

Vaccine development has been hampered by the long lead times and the high cost required to reach the market. The 2020 pandemic, caused by a new coronavirus (SARS-CoV-2) that was first reported in late 2019, has seen unprecedented rapid activity to generate a vaccine, which belies the traditional vaccine development cycle. Critically, much of this progress has been leveraged off existing technologies, many of which had their beginnings in influenza vaccine development. This commentary outlines the most promising of the next generation of non-egg-based influenza vaccines including new manufacturing platforms, structure-based antigen design/computational biology, protein-based vaccines including recombinant technologies, nanoparticles, gene- and vector-based technologies, as well as an update on activities around a universal influenza vaccine.