Search Results (164)

Background: The emergence of checkpoint inhibitors (CPIs) has significantly improved survival outcomes in later-stage melanoma. However, the efficacy of these treatments remains limited, with around 50% of later-stage melanoma patients experiencing recurrence. As variable response rates to CPIs persist, the development of cancer vaccines has emerged as a potential strategy to augment antitumor immune responses. Results: This review compares two promising personalized therapeutic cancer vaccine trials in advanced melanoma: Elios Therapeutics’ Tumor Lysate (TL) vaccine and Moderna’s mRNA-4157 vaccine. The TL vaccine, which utilizes yeast cell wall particles (YCWPs) loaded with autologous tumor lysate, and the mRNA-4157 vaccine, which encodes up to 34 patient-specific neoantigens, both aim to stimulate robust tumor-specific immune responses. Both trials were phase 2b randomized studies, with Elios Therapeutics’ trial employing a double-blind, placebo-controlled design, while Moderna’s was open-label. Both trials had roughly equivalent sample sizes (n = 187 and n = 157, respectively) with similar demographics and disease characteristics. The TL trial reported improvements in disease-free survival (DFS) with a hazard ratio (HR) of 0.52 (p < 0.01) over 36 months, whereas the mRNA-4157 trial demonstrated improvements in recurrence-free survival (RFS) with an HR of 0.56 (p = 0.053) over 18 months. The TL vaccine exhibited lower rates of related grade 3 adverse events (<1%) compared to the mRNA vaccine (12%). Key differences between the two trials include the use of CPIs, with 100% of patients in the mRNA trial receiving pembrolizumab versus 37% of the patients in the TL trial receiving either an anti-PD-1 or anti-CTLA-4. The production processes also varied significantly, with the mRNA vaccine requiring individualized sequencing and a 9-week production time, while the TL vaccine utilized tumor lysate with a 1–3-day production time. Conclusions: While both vaccines demonstrated promising efficacy, future phase 3 trials are needed to further evaluate their potential as adjuvant therapies for melanoma. This review highlights the comparative strengths and limitations of these vaccine platforms, providing insight into the evolving landscape of adjuvant cancer vaccines. Full article

Background/Objectives: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2), has resulted in 777 million cases worldwide. Various vaccines have been approved to control the spread of COVID-19, with mRNA vaccines (Pfizer and Moderna) being widely used in the USA. We conducted a prospective longitudinal study to analyze the immune response elicited by two/three and four doses of monovalent mRNA vaccines in both vaccinated individuals and those who experienced breakthrough infections. Participants were stratified into different age groups: 18–40, 41–60, and over 60 years. Methods: We assessed cross-variant neutralization responses in two cohorts—Cohort I: n = 167 (serum), Cohort II: n = 92 (serum and nasal swab) samples—using infectious virus microneutralization assay (MN) and antibody (IgG or IgA) binding ELISA titers to the spike protein receptor binding domain (RBD). Samples were collected from the Louisville Metro–Jefferson County Co-Immunity Project, a federally funded, population-based study for the surveillance of SARS-CoV-2 in Jefferson County, Kentucky during 2020–2022, involving both health care workers and a local community. Results: Individuals who received two doses of the mRNA vaccine exhibited reduced neutralization against Beta, Delta, and Omicron BA.1 variants compared to wildtype Wuhan, with further decline observed six months post-booster vaccination. However, individuals who experienced natural COVID-19 infection (breakthrough) after receiving two vaccine doses showed enhanced neutralization and antibody responses, particularly against Omicron BA.1. Following the 3rd dose, antibodies and neutralization responses were restored. Among triple-vaccinated individuals, reduced neutralization was observed against Omicron variants BA.1, BA.5, and BA.2 compared to Wuhan. Neutralization responses were better against BA.2 variant compared to BA.1 and BA.5. However, individuals who received three doses of vaccine and experienced a breakthrough infection (n = 45) elicited significantly higher neutralizing antibodies responses against all Omicron subvariants compared to vaccinated individuals. Interestingly, nasal swab samples collected from volunteers with breakthrough infection showed significantly elevated spike-reactive mucosal IgA antibodies and enhanced cross neutralization against BA.1, BA.2, and BA.5 compared to individuals who received only three vaccine doses. Conclusions: mRNA vaccination elicits a strong systemic immune response by boosting serum neutralizing antibodies (NAb), although this protection wanes over time, allowing new variants to escape neutralization. Breakthrough individuals have extra enrichment in nasal NAb offering protection against emerging variants. This longitudinal immune profiling underscores the strengthening of pandemic preparedness and supports the development of durable mucosal vaccines against respiratory infectious disease. Full article

Background/Objectives: The recent COVID-19 pandemic caused by SARS-CoV-2 infection has highlighted the need for protocols for rapid development of efficient screening methods to search for the optimal mRNA vaccine structures against mutable viral agents. The unmatched success of mRNA vaccines by Pfizer and Moderna encoding the spike protein of SARS-CoV-2 confirms the potential of lipid nanoparticles for mRNA delivery for an accelerated development of new vaccines. The efficacy of vaccination and the production cost of mRNA-based vaccines largely depend on the composition of mRNA components, since the synthesis of an immunogenic protein requires precise and efficient translation in vivo. The composition of 5′ and 3′ UTR combinations of mRNA has a strong impact on the translation efficiency. The major objective of this study was to increase the probability of producing the immunogenic protein encoded by vaccine mRNA. For this purpose, we proposed to find a new combination of natural UTRs and, in parallel with that, to design and test the system for in vivo selection of translationally active UTRs. Methods: By using Ribo-Seq analysis, sets of candidate short UTRs were generated. These UTRs were tested both in cell cultures and in mice for effective production of secreted nanoluciferase (NLuc) and the S protein of SARS-CoV-2. A combination of the most effective UTRs was used to generate a prototype of an mRNA vaccine capable of inducing neutralizing antibodies against coronavirus. Results: The usefulness of the selected UTRs for vaccine development was tested by implicating the full-length coding sequence of SARS-CoV-2 S protein to produce the main immunogen. As a result, the system for functional screening of UTRs was created by using the NLuc gene. Conclusions: The proposed approach allows non-invasive quantitative assessment of the translational activity of UTRs in the blood serum of mice. By using the full-length sequence of SARS-CoV-2 S protein as a prototype, we demonstrated that the combination of UTRs selected using our luciferase-based reporter assay induces IgG titers and neutralization rates comparable to those obtained by using UTRs from commercial S-protein-based mRNA vaccines. Full article

mRNA vaccines have demonstrated considerable efficacy and safety against SARS-CoV-2, limiting the pandemic burden worldwide. The emergence of new variants of concern and the decline in neutralizing activity observed several weeks post-vaccination reinforced the call for repeated mRNA vaccination. We and others have shown that vaccine efficacy does not exclusively rely on antibody neutralizing activites; Fc-effector functions play an important role as well. However, it is well known that long-term exposure and repeated antigen stimulation elicit the IgG4 subclass of antibodies, which are inefficient at mediating Fc-effector functions. In this regard, recent studies highlighted concerns about IgG4 induction by mRNA vaccines. Here, we explored the impact of repeated mRNA vaccination on IgG4 induction and its impact on Fc-effector functions. We observed anti-Spike IgG4 elicitation after three doses of mRNA vaccine; the antibody levels further increased with additional doses. Vaccine-elicited IgG4 preferentially bound the ancestral D614G Spike. We also observed that Breakthrough Infection (BTI) after several doses of vaccine strongly increased IgG1 levels but had no impact on IgG4 levels, thereby improving Fc-effector functions. Finally, we observed that elderly donors vaccinated with Moderna mRNA vaccines elicited higher IgG4 levels and presented lower Fc-effector functions than donors vaccinated with the Pfizer mRNA vaccine. Altogether, our results highlight the importance of monitoring the IgG subclasses elicited by vaccination. Full article

Vaccination has been instrumental in curbing the transmission of SARS-CoV-2 and mitigating the severity of clinical manifestations associated with COVID-19. Numerous COVID-19 vaccines have been developed to this effect, including BioNTech-Pfizer and Moderna’s mRNA vaccines, as well as adenovirus vector-based vaccines such as Oxford–AstraZeneca. However, the emergence of new variants and subvariants of SARS-CoV-2, characterized by enhanced transmissibility and immune evasion, poses significant challenges to the efficacy of current vaccination strategies. In this review, we aim to comprehensively outline the landscape of emerging SARS-CoV-2 variants of concern (VOCs) and sub-lineages that have recently surfaced in the post-pandemic years. We assess the effectiveness of existing vaccines, including their booster doses, against these emerging variants and subvariants, such as BA.2-derived sub-lineages, XBB sub-lineages, and BA.2.86 (Pirola). Furthermore, we discuss the latest advancements in vaccine technology, including multivalent and pan-coronavirus approaches, along with the development of several next-generation coronavirus vaccines, such as exosome-based, virus-like particle (VLP), mucosal, and nanomaterial-based vaccines. Finally, we highlight the key challenges and critical areas for future research to address the evolving threat of SARS-CoV-2 subvariants and to develop strategies for combating the emergence of new viral threats, thereby improving preparedness for future pandemics. Full article

Over the past 20 years, intensive research has been conducted on the development of therapeutic mRNA, leading to numerous discoveries that have enabled its use in therapy. The main achievements in this field include increasing mRNA stability, reducing its immunogenicity (i.e., its ability to trigger an immune response), and solving the challenge of delivering mRNA into cells—all to achieve a therapeutic effect. The aim of this study was to review the scientific literature on the use of mRNA technology in the production of vaccines. Various methods of applying mRNA technology that could potentially be introduced into clinical practice in the future are described. A detailed analysis was conducted on the approved COVID-19 vaccines developed by Pfizer/BioNTech (New York, NY, USA) and Moderna (Kirkland, QC, Canada), as their introduction marked a groundbreaking moment in the advancement of mRNA technology. This study was based on the latest scientific literature from reputable publishers and medical databases such as PubMed and ClinicalTrials. In conclusion, mRNA technology is currently experiencing rapid development, significantly driven by the ongoing COVID-19 pandemic. The application of this technology holds great potential not only for vaccines against infectious diseases but also for cancer treatment. However, further research is necessary to facilitate its broader clinical implementation. Full article

Background: The COVID-19 pandemic highlighted the vulnerability of immunocompromised individuals, including liver transplant recipients (LTRs), who often exhibit reduced vaccine immunogenicity. While initial vaccine doses and subsequent boosters improved immune response, LTRs were prioritized for vaccination. Studies have shown increased antibody response after each booster dose. Vaccine hesitancy, defined as delayed or refused vaccination despite availability, poses a public health challenge, often fueled by misinformation. This study aimed to evaluate anti-spike antibody responses in vaccinated LTRs after two initial doses and at least one booster, also assessing adherence to subsequent doses. Methods: We conducted a retrospective observational study at a transplant center in Milan, Italy, between January 2021 and December 2023. LTRs who had received four or more doses of mRNA vaccines (Pfizer or Moderna) were included. Anti-spike antibody levels were measured 60–80 days after each dose. Data on vaccination status were collected in January 2024. Statistical analysis was performed to compare antibody responses and identify predictive factors. Results: LTRs showed a significant increase in anti-spike antibody responses after the first booster compared to the second dose with a trend versus a further increase following the fourth dose in a subgroup of the patients receiving two booster doses. However, adherence to booster doses decreased over time. In LTRs, predictors of a weaker response after the second dose were chronic kidney disease and metabolic etiology at transplant. Conclusions: The study highlighted that in LTRs, multiple doses of the COVID-19 vaccine led to a continuous increase in anti-spike antibody responses. The progressive decline in adherence of LTRs “to further booster doses” should be related to the fact that after the spread of vaccination programs worldwide, COVID-19 is still a current infection, but it is much less severe than before. Full article

Background/Objectives: mRNA vaccines have demonstrated strong immunogenicity and efficacy against SARS-CoV-2. However, the extent of antibody cross-reactivity against human seasonal coronaviruses, such as NL63, remains unclear. Furthermore, it is unknown whether pre-existing antibody responses against NL63 might influence the outcome of SARS-CoV-2 mRNA vaccination. Methods: We used a flow cytometry-based serological assay and an in vitro neutralization assay to analyze NL63 antibody responses in sera from SARS-CoV-2 mRNA-vaccinated mice and plasma samples from a vaccinated human cohort. Results: We found that the Moderna mRNA-1273 vaccine can generate cross-reactive antibodies against NL63. Importantly, SARS-CoV-2 mRNA vaccination did not boost pre-existing anti-NL63 responses in humans, and pre-existing NL63 antibody levels did not affect the antibody response induced by SARS-CoV-2 mRNA vaccination. Conclusions: These findings suggest that while SARS-CoV-2 mRNA vaccination can induce cross-reactive antibodies against NL63, pre-existing immunity to this seasonal coronavirus does not appear to significantly impact vaccine immunogenicity. These findings contribute to our understanding of the complex interplay between pre-existing immunity to seasonal coronaviruses and the immune response generated by SARS-CoV-2 mRNA vaccines. Full article

Melanoma, an aggressive skin cancer, presents significant therapeutic challenges. Consequently, innovative treatment strategies beyond conventional chemotherapy, radiation, and surgery are actively explored. This review discusses the evolution of immunotherapy in advanced melanoma, highlighting PD-1/PD-L1 inhibitors, mRNA vaccines, Talimogene Laherparepvec (T-VEC), and tumor-infiltrating lymphocyte (TIL) therapies. PD-1/PD-L1 inhibitors such as pembrolizumab and nivolumab block immune checkpoints, promoting T-cell cytotoxic activity and improving overall survival in patients with advanced melanoma. T-VEC, a modified oncolytic herpes virus, promotes a systemic anti-tumor response while simultaneously lysing malignant cells. mRNA vaccines, such as Moderna’s mRNA-4157/V940, take advantage of malignant-cell-specific neoantigens to amplify the adaptive immune response while protecting healthy tissue. TIL therapy is a form of therapy involving ex vivo expansion and reinfusion of the patient’s tumor-specific lymphocytes and has been shown to provide durable tumor control. While these therapies have demonstrated promising clinical outcomes, challenges such as tumor resistance, high financial burden, and limited accessibility pose challenges to their widespread use. This review explores combination therapies such as PD-L1 inhibitors with mRNA vaccines, or TIL therapy, which aim to enhance treatment through synergistic approaches. Further research is required to optimize these combinations, address barriers preventing their use, and control adverse events. Full article

Background/Objectives: In this ongoing, multicenter, global cohort observational study, phenotypes of headaches after COVID-19 vaccination were directly compared between different vaccines. Methods: Phenotypes of postvaccinal headache were recorded in 18,544 participants. The study was launched immediately after the start of the global COVID-19 vaccination campaign on 12 January 2021 and continued until 1 August 2023. Specific aspects of headaches and related variables were collected via an online questionnaire. The clinical headache characteristics of patients vaccinated with the Comirnaty (BioNTech), Jcovden (Johnson & Johnson), Sputnik V (Gamelaya), Covilo (Sinopharm), Spikevax (Moderna), Vaxzevria (AstraZeneca), and Convidecia (CanSino Biologics) vaccines were investigated. Results: Across all vaccines, the median and mean latency of headache onset after vaccine administration were 12 h and 23.3 h, respectively. The median and mean headache duration were 12 h and 23.3 h, respectively. When the nonreplicating viral vector vaccine Sputnik V was used, headaches occurred the fastest, with a latency of 17 h. The latencies for the Vaxzevria and Convidecia nonreplicating viral vector vaccines were 14.9 h and 19.1 h, respectively. The Covilo inactivated whole-virus vaccine had a latency of 20.5 h. The latencies of the mRNA-based Comirnaty and Spikevax vaccines were 26.0 h and 22.02 h, respectively. Analysis of variance revealed no significant differences in the mean duration of postvaccinal headache for the vaccines tested. Compared with the Comirnaty, Covilo, and Vaxzevria vaccines, the Spikevax vaccine induced significantly greater headache intensities. Vaxzevria was associated with a significantly higher frequency of concomitant symptoms than the other vaccines. Conclusions: The phenotype of postvaccinal headache can vary significantly between vaccines. These results have clinical implications for differentiating between postvaccinal headache and other primary and secondary headaches. This knowledge is clinically relevant in differentiating life-threatening vaccination complications, such as thrombotic syndromes, which are also associated with headaches. Based on these results, new diagnostic criteria for postvaccinal headaches can be developed. Full article

Respiratory syncytial virus (RSV) causes significant morbidity and mortality, especially in young children and the elderly. RSV vaccine development puzzled vaccinologists for years. Safety concerns of initial formulations, the lack of an absolute correlate of protection, and the need for selecting appropriate virus attenuation and antigen–adjuvant combinations contributed to delayed vaccine production. The recent stabilization of the RSV-F glycoprotein in the prefusion (preF) conformation that constitutes the primary target of RSV-neutralizing antibodies was key for efficient vaccine design. Two protein subunit vaccines (GSK’s Arexvy and Pfizer’s Abrysvo) and one mRNA RSV vaccine (Moderna’s mRESVIA) are now available. This article aims to provide a comparative overview of the safety and efficacy of novel RSV vaccines that are approved for the prevention of RSV-lower respiratory tract disease (LRTD) in adults 60 years of age and older, with updated recommendations calling for the expansion of vaccination to all adults at increased risk for severe RSV disease. Abrysvo is the only vaccine indicated for use in pregnancy to prevent RSV-LRTD in infants from birth to 6 months of age. We provide a comparative assessment of the efficacy of approved RSV vaccines over a maximum of three seasons, summarizing currently available data. We conclude that despite the decreasing vaccine efficacy over time, which should be anticipated for a virus that is characterized by short-term immunity, efficacy was clinically meaningful over placebo. The increased risk of Guillain–Barré syndrome post vaccination with Abrysvo or Arexvy, which prompted the FDA to require the inclusion of such warnings in the prescribing information of these two RSV vaccines, should be prioritized and investigated thoroughly. Furthermore, ongoing vaccine surveillance and further evaluation, particularly among immunocompromised patients, frail elderly subjects, and young infants that were under- or not represented in pivotal clinical trials, are necessary. As in the success story of combined pediatric vaccines, combination vaccines, conferring protection against several respiratory illnesses in one dose, could help improve vaccine acceptance and coverage rates in older adults. Full article

This systematic review evaluated the effectiveness and side effects of various COVID-19 vaccines, with a focus on Trinidad and Tobago. The Pfizer-BioNTech and Moderna vaccines demonstrated the highest efficacy, particularly against COVID-19 variants, while Janssen and Sinopharm were comparatively less effective. mRNA vaccines, such as Pfizer-BioNTech and Oxford-AstraZeneca, were associated with more frequent and severe side effects, including soreness, fever, and cardiovascular issues. The review also identified significant gaps in the current scientific literature regarding COVID-19 vaccination issues in Trinidad and Tobago. These gaps highlight the need for comprehensive research to address vaccination challenges, including public health communication, equitable access, and local perceptions of vaccine safety. This analysis provides a foundation for developing targeted strategies to improve vaccine effectiveness in the region. Full article

Background/objectives: Coronavirus-19 (COVID-19) vaccines represent a significant milestone in the fight against coronavirus disease. Ongoing post-marketing surveillance and research are crucial for ensuring vaccine safety and effectiveness, aiding public health planning. Methods: Our retrospective cohort study included Albertans five years and older and vaccinated with at least one dose of an approved COVID-19 vaccine between 14 December 2020 and 30 April 2022. This epidemiological study aimed to determine the incidence of reported adverse events following immunization (AEFI) in Alberta and identify associated risk factors. Results: The study included 3,527,106 vaccinated Albertans who met the study inclusion criteria. A total of 2541 individuals (72.0 per 100,000) reported an AEFI, with 2759 adverse events, most of which occurred following the first dose of vaccine and within the first week post-vaccination. Of these, 70.4% were female, and the highest incidence was in the 35–54 age group. Given that mRNA vaccines were predominantly administered across Canada, we report AEFI rates (per 100,000 doses) for the mRNA vaccine brands at 27.7 for Pfizer and 40.7 for Moderna. Allergic events were the most frequently reported AEFI, followed by adenopathy. Logistic regression analysis indicated that sex (with females at higher risk), presence of comorbidities, days to symptom onset, vaccine type (mRNA vs. mixed doses), and the number of doses were significant factors associated with an AEFI event. Conclusions: Our study provides valuable information to guide policies surrounding COVID-19 vaccination. While the risk of serious adverse events was low in the population-based sample, further research is warranted to identify and investigate other possible risk factors that are still unknown. Full article

The COVID-19 pandemic has significantly accelerated progress in RNA-based therapeutics, particularly through the successful development and global rollout of mRNA vaccines. This review delves into the transformative impact of the pandemic on RNA therapeutics, with a strong focus on lipid nanoparticles (LNPs) as a pivotal delivery platform. LNPs have proven to be critical in enhancing the stability, bioavailability, and targeted delivery of mRNA, facilitating the unprecedented success of vaccines like those developed by Pfizer-BioNTech and Moderna. Beyond vaccines, LNP technology is being explored for broader therapeutic applications, including treatments for cancer, rare genetic disorders, and infectious diseases. This review also discusses emerging RNA delivery systems, such as polymeric nanoparticles and viral vectors, which offer alternative strategies to overcome existing challenges related to stability, immune responses, and tissue-specific targeting. Additionally, we examine the pandemic’s influence on regulatory processes, including the fast-tracked approvals for RNA therapies, and the surge in research funding that has spurred further innovation in the field. Public acceptance of RNA-based treatments has also grown, laying the groundwork for future developments in personalized medicine. By providing an in-depth analysis of these advancements, this review highlights the long-term impact of COVID-19 on the evolution of RNA therapeutics and the future of precision drug delivery technologies. Full article

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has prompted a massive global vaccination campaign, leading to the rapid development and deployment of several vaccines. Various COVID-19 vaccines are under different phases of clinical trials and include the whole virus or its parts like DNA, mRNA, or protein subunits administered directly or through vectors. Beginning in 2020, a few mRNA (Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273) and adenovirus-based (AstraZeneca ChAdOx1-S and the Janssen Ad26.COV2.S) vaccines were recommended by WHO for emergency use before the completion of the phase 3 and 4 trials. These vaccines were mostly administered in two or three doses at a defined frequency between the two doses. While these vaccines, mainly based on viral nucleic acids or protein conferred protection against the progression of SARS-CoV-2 infection into severe COVID-19, and prevented death due to the disease, their use has also been accompanied by a plethora of side effects. Common side effects include localized reactions such as pain at the injection site, as well as systemic reactions like fever, fatigue, and headache. These symptoms are generally mild to moderate and resolve within a few days. However, rare but more serious side effects have been reported, including allergic reactions such as anaphylaxis and, in some cases, myocarditis or pericarditis, particularly in younger males. Ongoing surveillance and research efforts continue to refine the understanding of these adverse effects, providing critical insights into the risk-benefit profile of COVID-19 vaccines. Nonetheless, the overall safety profile supports the continued use of these vaccines in combating the pandemic, with regulatory agencies and health organizations emphasizing the importance of vaccination in preventing COVID-19’s severe outcomes. In this review, we describe different types of COVID-19 vaccines and summarize various adverse effects due to autoimmune and inflammatory response(s) manifesting predominantly as cardiac, hematological, neurological, and psychological dysfunctions. The incidence, clinical presentation, risk factors, diagnosis, and management of different adverse effects and possible mechanisms contributing to these effects are discussed. The review highlights the potential ambivalence of human response post-COVID-19 vaccination and necessitates the need to mitigate the adverse side effects. Full article