Maintaining Safety with SARS-CoV-2 Vaccines

Beyond Lipids: Exploring Advances in Polymeric Gene Delivery in the Lipid Nanoparticles Era

The recent success of gene therapy during the COVID-19 pandemic has underscored the importance of effective and safe delivery systems. Complementing lipid-based delivery systems, polymers present a promising alternative for gene delivery. Significant advances have been made in the recent past, with multiple clinical trials progressing beyond phase I and several companies actively working on polymeric delivery systems which provides assurance that polymeric carriers can soon achieve clinical translation. The massive advantage of structural tunability and vast chemical space of polymers is being actively leveraged to mitigate shortcomings of traditional polycationic polymers and improve the translatability of delivery systems. Tailored polymeric approaches for diverse nucleic acids and for specific subcellular targets are now being designed to improve therapeutic efficacy. This review describes the recent advances in polymer design for improved gene delivery by polyplexes and covalent polymer-nucleic acid conjugates. The review also offers a brief note on novel computational techniques for improved polymer design. The review concludes with an overview of the current state of polymeric gene therapies in the clinic as well as future directions on their translation to the clinic.

Identification of cross reactive T cell responses in adenovirus based COVID 19 vaccines

Vaccination has proven to be a valuable tool to combat SARS-CoV-2. However, reports of rare adverse reactions such as thrombosis/thrombocytopenia syndrome after ChAdOx1 nCoV-19 vaccination have caused scientific, public and media concern. ChAdOx1 was vectorised from the Y25 chimpanzee adenovirus, which was selected due to low human seroprevalence to circumvent pre-existing immunity. In this study, we aimed to explore patterns of T-cell activation after SARS-CoV-2 COVID-19 vaccine exposure in vitro using PBMCs collected from pre-pandemic ChAdOx1 nCoV-19 naïve healthy donors (HDs), and ChAdOx1 nCoV-19 and Pfizer vaccinated controls. PBMCs were assessed for T-cell proliferation using the lymphocyte transformation test (LTT) following exposure to SARS-CoV-2 COVID-19 vaccines. Cytokine analysis was performed via intracellular cytokine staining, ELISpot assay and LEGENDplex immunoassays. T-cell assays performed in pre-pandemic vaccine naïve HDs, revealed widespread lymphocyte stimulation after exposure to ChAdOx1 nCoV-19 (95%), ChAdOx-spike (90%) and the Ad26.COV2. S vaccine, but not on exposure to the BNT162b2 vaccine. ICS analysis demonstrated that CD4+ CD45RO+ memory T-cells are activated by ChAdOx1 nCoV-19 in vaccine naïve HDs. Cytometric immunoassays showed ChAdOx1 nCoV-19 exposure was associated with the release of proinflammatory and cytotoxic molecules, such as IFN-γ, IL-6, perforin, granzyme B and FasL. These studies demonstrate a ubiquitous T-cell response to ChAdOx1 nCoV-19 and Ad26.COV2. S in HDs recruited prior to the SARS-CoV-2 pandemic, with T-cell stimulation also identified in vaccinated controls. This may be due to underlying T-cell cross-reactivity with prevalent human adenoviruses and further study will be needed to identify T-cell epitopes involved.

Incidence and management of the main serious adverse events reported after COVID-19 vaccination

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2n first appeared in Wuhan, China in 2019. Soon after, it was declared a pandemic by the World Health Organization. The health crisis imposed by a new virus and its rapid spread worldwide prompted the fast development of vaccines. For the first time in human history, two vaccines based on recombinant genetic material technology were approved for human use. These mRNA vaccines were applied in massive immunization programs around the world, followed by other vaccines based on more traditional approaches. Even though all vaccines were tested in clinical trials prior to their general administration, serious adverse events, usually of very low incidence, were mostly identified after application of millions of doses. Establishing a direct correlation (the cause-effect paradigm) between vaccination and the appearance of adverse effects has proven challenging. This review focuses on the main adverse effects observed after vaccination, including anaphylaxis, myocarditis, vaccine-induced thrombotic thrombocytopenia, Guillain-Barré syndrome, and transverse myelitis reported in the context of COVID-19 vaccination. We highlight the symptoms, laboratory tests required for an adequate diagnosis, and briefly outline the recommended treatments for these adverse effects. The aim of this work is to increase awareness among healthcare personnel about the serious adverse events that may arise post-vaccination. Regardless of the ongoing discussion about the safety of COVID-19 vaccination, these adverse effects must be identified promptly and treated effectively to reduce the risk of complications.

The respiratory syncytial virus vaccines are here: Implications for solid organ transplantation

In 2023, the Food and Drug Administration approved 2 recombinant subunit respiratory syncytial virus (RSV) vaccines based on prefusion RSV F glycoproteins for the prevention of RSV-associated lower respiratory tract disease. These vaccines were subsequently recommended for individuals ≥60 years of age using shared clinical decision-making by the Center for Disease Control and Prevention's Advisory Committee on Immunization Practices. The development, deployment, and uptake of respiratory virus vaccines are of particular importance for solid organ recipients who are at higher risk of infectious complications and poor clinical outcomes, including from RSV-associated lower respiratory tract disease, compared to patients without immunocompromise. This review aims to summarize what is currently known about the burden of RSV disease in solid organ transplantation, to describe the currently available tools to mitigate the risk, and to highlight considerations regarding the implementation of these vaccines before and after transplantation. We also explore areas of unmet need for organ transplant recipients including questions of RSV vaccine effectiveness and safety, inequities in disease and vaccine access based on race and socioeconomic status, and expansion of coverage to immunocompromised individuals below the age of 60 years.

Striving for Uniformity: A Review on Advances and Challenges To Achieve Uniform Polyethylene Glycol

Poly(ethylene glycol) (PEG) is the polymer of choice in drug delivery systems due to its biocompatibility and hydrophilicity. For over 20 years, this polymer has been widely used in the drug delivery of small drugs, proteins, oligonucleotides, and liposomes, improving the stability and pharmacokinetics of many drugs. However, despite the extensive clinical experience with PEG, concerns have emerged related to its use. These include hypersensitivity, purity, and nonbiodegradability. Moreover, conventional PEG is a mixture of polymers that can complicate drug synthesis and purification leading to unwanted immunogenic reactions. Studies have shown that uniform PEGylated drugs may be more effective than conventional PEGylated drugs as they can overcome issues related to molecular heterogeneity and immunogenicity. This has led to significant research efforts to develop synthetic procedures to produce uniform PEGs (monodisperse PEGs). As a result, iterative step-by-step controlled synthesis methods have been created over time and have shown promising results. Nonetheless, these procedures have presented numerous challenges due to their iterative nature and the requirement for multiple purification steps, resulting in increased costs and time consumption. Despite these challenges, the synthetic procedures went through several improvements. This review summarizes and discusses recent advances in the synthesis of uniform PEGs and its derivatives with a focus on overall yields, scalability, and purity of the polymers. Additionally, the available characterization methods for assessing polymer monodispersity are discussed as well as uniform PEG applications, side effects, and possible alternative polymers that can overcome the drawbacks.

A study on the side effects caused by the Pfizer/BioNTech COVID-19 vaccine: Focus on IgG antibodies and serological biomarkers

Introduction

The SARS-CoV-2 pandemic that spread swiftly is now a major global public health issue. Vaccines are currently being distributed in an effort to limit the viral transmission and mortality. The aim of the study was monitoring of both safety and efficacy in determining the overall effectiveness of the vaccine and identifying any potential safety concerns.

Material and methods

A retrospective, cross-sectional study employing a validated 13-item structured questionnaire divided into two sections was performed between March 2022 and September 2022. Different post-vaccination side effects (SE) according to symptoms severity in terms of age and sex for participants were reported. Additionally, some pertinent serological assays for participants' post-vaccinations were investigated.

Results

A total of 502 participants (male: 262, female: 240) with comorbidity (healthy: 258, morbid: 244) who received two Pfizer/BioNTech mRNA vaccine doses were included. Importantly, second dose (D2) vaccination was associated with significantly more SE than single dose (D1) vaccination (p < 0.0001). In D1 vaccination injection site pain (ISP) (45%), followed by equal proportions of headache and fever (40%) were the most common vaccine SE, while in D2 vaccination, ISP (66%) and nausea (57%) were reported. In all, 97% (p < 0.0001) of participants were IgG antibody positive at D2 vaccination. Similarly, serum CR protein level was elevated significantly (p < 0.0001) corresponding to the severity of SE between D1 and D2. Significant differences in IgG concentration were found between D1 and D2 vaccination in different gender and age groups (p < 0.0001).

Conclusions

In light of the extensive data from this study, it is evident that mRNA vaccines, particularly the Pfizer/BioNTech vaccine, have proven to be highly safe and effective in mitigating the impact of the SARS-CoV-2 pandemic.

Durable protective efficiency provide by mRNA vaccines require robust immune memory to antigens and weak immune memory to lipid nanoparticles

The Pegylated lipids in lipid nanoparticle (LNPs) vaccines have been found to cause acute hypersensitivity reactions in recipients, and generate anti-LNPs immunity after repeated administration, thereby reducing vaccine effectiveness. To overcome these challenges, we developed a new type of LNPs vaccine (SAPC-LNPs) which was co-modified with sialic acid (SA) - lipid derivative and cleavable PEG - lipid derivative. This kind of mRNA vaccine can target dendritic cells (DCs) and rapidly escape from early endosomes (EE) and lysosomes with a total endosomal escape rate up to 98 %. Additionally, the PEG component in SAPC-LNPs was designed to detach from the LNPs under the catalysis of carboxylesterase in vivo, which reduced the probability of PEG being attached to LNPs entering antigen-presenting cells. Compared with commercially formulated vaccines (1.5PD-LNPs), mice treated with SAPC-LNPs generated a more robust immune memory to tumor antigens and a weaker immune memory response to LNPs, and showed lower side effects and long-lasting protective efficiency. We also discovered that the anti-tumor immune memory formed by SAPC-LNPs mRNA vaccine was directly involved in the immune cycle to rattack tumor. This immune memory continued to strengthen with multiple cycles, supporting that the immune memory should be incorporated into the theory of tumor immune cycle.

Safety and Tolerability of COVID-19 Vaccine in Mast Cell Disorders Real-Life Data from a Single Centre in Italy

Background In the past three years, COVID-19 has had a significant impact on the healthcare systems and people's safety worldwide. Mass vaccinations dramatically improved the health and economic damage caused by SARS-CoV-2. However, the safety of COVID-19 vaccines in patients at high risk of allergic reactions still has many unmet needs that should be clarified. Material and methods A retrospective, single-centre study was performed by collecting demographic and clinical data of patients with Mast Cell Disorders (MCDs) to evaluate the safety and tolerability of COVID-19 vaccinations. Moreover, any changes in the natural history of the underlying disease following the vaccine have been evaluated. Results This study included 66 patients affected with MCDs. Out of them, 52 (78.8%) received a COVID-19 vaccination and 41 (78.8%) completed the vaccination course. Premedication came first in 86.6% of our patients. A total of seven (4.5%) patients complained about an immediate reaction and two (1.3%) had a late reaction. Worsening of MCD history was observed in a single patient. Conclusions Despite the overall high risk of allergic reactions, our study did not reveal any increased risk for SARS-CoV-2 allergic reactions in MCD patients, thus supporting the recommendation in favour of the SARS-CoV-2 vaccination. However, due to the potentially increased rate of anaphylactic reactions, MCD patients should receive vaccine premedication and should be treated in a hospital setting after an allergological specialistic evaluation.

On the origin of the low immunogenicity and biosafety of a neutral α-helical polypeptide as an alternative to polyethylene glycol

Poly(ethylene glycol) (PEG) is a prominent synthetic polymer widely used in biomedicine. Despite its notable success, recent clinical evidence highlights concerns regarding the immunogenicity and adverse effects associated with PEG in PEGylated proteins and lipid nanoparticles. Previous studies have found a neutral helical polypeptide poly(γ-(2-(2-(2-methoxyethoxy)ethoxy)ethyl l-glutamate), namely L-P(EG3Glu), as a potential alternative to PEG, displaying lower immunogenicity. To comprehensively assess the immunogenicity, distribution, degradation, and biosafety of L-P(EG3Glu), herein, we employ assays including enzyme-linked immunosorbent assay, positron emission tomography-computed tomography, and fluorescent resonance energy transfer. Our investigations involve in vivo immune responses, biodistribution, and macrophage activation of interferon (IFN) conjugates tethered with helical L-P(EG3Glu) (L20k-IFN), random-coiled DL-P(EG3Glu) (DL20k-IFN), and PEG (PEG20k-IFN). Key findings encompass: minimal anti-IFN and anti-polymer antibodies elicited by L20k-IFN; length-dependent affinity of PEG to anti-PEG antibodies; accelerated clearance of DL20k-IFN and PEG20k-IFN linked to anti-IFN and anti-polymer IgG; complement activation for DL20k-IFN and PEG20k-IFN but not L20k-IFN; differential clearance with L20k-IFN kidney-based, and DL20k-IFN/PEG20k-IFN accumulation mainly in liver/spleen; enhanced macrophage activation by DL20k-IFN and PEG20k-IFN; L-P(EG3Glu) resistance to proteolysis; and safer repeated administrations of L-P(EG3Glu) in rats. Overall, this study offers comprehensive insights into the lower immunogenicity of L-P(EG3Glu) compared to DL-P(EG3Glu) and PEG, supporting its potential clinical use in protein conjugation and nanomedicines.

Nanomaterial-encapsulated STING agonists for immune modulation in cancer therapy

The cGAS-STING signaling pathway has emerged as a critical mediator of innate immune responses, playing a crucial role in improving antitumor immunity through immune effector responses. Targeting the cGAS-STING pathway holds promise for overcoming immunosuppressive tumor microenvironments (TME) and promoting effective tumor elimination. However, systemic administration of current STING agonists faces challenges related to low bioavailability and potential adverse effects, thus limiting their clinical applicability. Recently, nanotechnology-based strategies have been developed to modulate TMEs for robust immunotherapeutic responses. The encapsulation and delivery of STING agonists within nanoparticles (STING-NPs) present an attractive avenue for antitumor immunotherapy. This review explores a range of nanoparticles designed to encapsulate STING agonists, highlighting their benefits, including favorable biocompatibility, improved tumor penetration, and efficient intracellular delivery of STING agonists. The review also summarizes the immunomodulatory impacts of STING-NPs on the TME, including enhanced secretion of pro-inflammatory cytokines and chemokines, dendritic cell activation, cytotoxic T cell priming, macrophage re-education, and vasculature normalization. Furthermore, the review offers insights into co-delivered nanoplatforms involving STING agonists alongside antitumor agents such as chemotherapeutic compounds, immune checkpoint inhibitors, antigen peptides, and other immune adjuvants. These platforms demonstrate remarkable versatility in inducing immunogenic responses within the TME, ultimately amplifying the potential for antitumor immunotherapy.

A SARS-CoV-2 nanoparticle vaccine based on chemical conjugation of loxoribine and SpyCatcher/SpyTag

SARS-CoV-2 is a particularly transmissible virus that renders the worldwide COVID-19 pandemic and global severe respiratory distress syndrome. Protein-based vaccines hold great advantages to build the herd immunity for their specificity, effectiveness, and safety. Receptor-binding domain (RBD) of SARS-CoV-2 is an appealing antigen for vaccine development. However, adjuvants and delivery system are necessitated to enhance the immunogenicity of RBD. In the present study, RBD was chemically conjugated with loxoribine and SpyCatcher/SpyTag, followed by assembly to form a nanoparticle vaccine. Loxoribine (a TLR7/8 agonist) acted as an adjuvant, and nanoparticles functioned as delivery system for the antigen and the adjuvant. The nanoparticle vaccine elicited high RBD-specific antibody titers, high neutralizing antibody titer, and strong ACE2-blocking activity. It stimulated high splenic levels of Th1-type cytokines (IFN-γ and IL-2) and Th2-type cytokines (IL-4 and IL-5) in BALB/c mice. It promoted the splenocyte proliferation, enhanced the CD4+ and CD8+ T cell percentage and stimulated the maturation of dendritic cells. The vaccine did not render apparent toxicity to the organs of mice. Thus, the nanoparticle vaccine was of potential to act as a preliminarily safe and effective candidate against SARS-CoV-2.

Poly(ethyl ethylene phosphate): Overcoming the "Polyethylene Glycol Dilemma" for Cancer Immunotherapy and mRNA Vaccination

Polyethylene glycol conjugation (PEGylation) is the most successful strategy to promote the stability, pharmacokinetics, and efficacy of therapeutics; however, anti-PEG antibodies induced by repeated treatments raise serious concerns about the future of PEGylated therapeutics. In order to solve the "PEG dilemma", polymers with excellent water solubility and biocompatibility are urgently desired to attenuate the generation of anti-PEG antibodies. Here, poly(ethyl ethylene phosphate) (PEEP) with excellent degradability and stealth effects is used as an alternative to PEG to overcome the "PEG dilemma". PEEPylated liposomes exhibit lower immunogenicity and generate negligible anti-PEEP antibodies (IgM and IgG) after repeated treatments. In vivo studies confirm that PEEPylated liposomes loaded with oxaliplatin (PEEPlipo@OxPt) show better pharmacokinetics compared to PEGlipo@OxPt, and they exhibit potent antitumor performances, which can be further promoted with checkpoint blockade immunotherapy. In addition, PEEPylated lipid nanoparticle is also used to develop an mRNA vaccine with the ability to evoke a potent antigen-specific T cell response and achieve excellent antitumor efficacy. PEEP shows promising potentials in the development of next-generation nanomedicines and vaccines with higher safety and efficacy.

Real-Life Experience in the Efficacy and Safety of COVID-19 Vaccination in Patients with Advanced Cirrhosis

COVID-19 infections accelerate liver decompensation and serious liver-related co-morbidities. The aim is to evaluate the safety and impact of COVID vaccines on hepatic disease progression in patients with advanced liver disease and to identify parameters that predict the occurrence of complications. The study involved 70 patients with advanced liver disease who were vaccinated with different COVID vaccines from January 2021 to April 2022. They were evaluated clinically. The laboratory investigation included a complete blood count, liver and kidney function tests, calculation of CTP and MELD scores, plasma levels of ammonia, abdominal ultrasound, and upper GI endoscopy. Twenty patients had experienced complications 64 ± 12 days from the last dose of a vaccination. Twenty patients (28.6%) developed hepatic decompensation and hypothyroidism (n = 11, 15.7%), and five (7.14%) patients developed splanchnic thrombosis. There were no COVID-19 reinfections except for two patients who received Sinopharm and developed vaccine-associated enhanced disease (2.9%). Complications after COVID vaccinations were correlated with ALT (r = 0.279, p = 0.019), serum sodium (r = -0.30, p = 0.005), creatinine (r = 0.303, p = 0.011), liver volume (LV) (r = -0.640, p = 0.000), and MELD score (r = 0.439, p = 0.000). Multivariate logistic regression revealed that LV is the only independent predictor (p = 0.001). LV ≤ 682.3 has a sensitivity of 95.24% and a specificity of 85.71% in predicting complications with an AUC of 0.935, p < 0.001. In conclusion, the hepatic reserve and prognosis in liver cirrhosis should be evaluated prior to COVID vaccinations using the MELD score and liver volume as promising risk stratification criteria. In summary, the research proposes a novel triaging strategy that involves utilizing the MELD score and liver volume as risk stratification parameters of the hepatic reserve and prognosis of advanced liver cirrhosis prior to COVID immunization to determine who should not receive a COVID vaccination.

Straight to the point: targeted mRNA-delivery to immune cells for improved vaccine design

With the deepening of our understanding of adaptive immunity at the cellular and molecular level, targeting antigens directly to immune cells has proven to be a successful strategy to develop innovative and potent vaccines. Indeed, it offers the potential to increase vaccine potency and/or modulate immune response quality while reducing off-target effects. With mRNA-vaccines establishing themselves as a versatile technology for future applications, in the last years several approaches have been explored to target nanoparticles-enabled mRNA-delivery systems to immune cells, with a focus on dendritic cells. Dendritic cells (DCs) are the most potent antigen presenting cells and key mediators of B- and T-cell immunity, and therefore considered as an ideal target for cell-specific antigen delivery. Indeed, improved potency of DC-targeted vaccines has been proved in vitro and in vivo. This review discusses the potential specific targets for immune system-directed mRNA delivery, as well as the different targeting ligand classes and delivery systems used for this purpose.

Esterase-Labile Quaternium Lipidoid Enabling Improved mRNA-LNP Stability and Spleen-Selective mRNA Transfection

Ionizable cationic lipids are recognized as an essential component of lipid nanoparticles (LNPs) for messenger RNA (mRNA) delivery but can be confounded by low lipoplex stability with mRNA during storage and in vivo delivery. Herein, the rational design and combinatorial synthesis of esterase-triggered decationizable quaternium lipid-like molecules (lipidoids) are reported to develop new LNPs with high delivery efficiency and improved storage stability. This top lipidoid carries positive charges at the physiological condition but promptly acquires negative charges in the presence of esterase, thus permitting stable mRNA encapsulation during storage and in vivo delivery while balancing efficient mRNA release in the cytosol. An optimal LNP formulation is then identified through orthogonal optimization, which enables efficacious mRNA transfection selectively in the spleen following intravenous administration. LNP-mediated delivery of ovalbumin (OVA)-encoding mRNA induces efficient antigen expression in antigen-presenting cells and elicits robust antigen-specific immune responses against OVA-transduced tumors. The work demonstrates the potential of decationizable quaternium lipidoids for spleen-selective RNA transfection and cancer immunotherapy.

The usability of testing skin reaction applying skin prick tests with Comirnaty (Pfizer, USA) vaccine in detecting the risk of developing post-vaccination immediate hypersensitivity response (anaphylaxis) after administration of this vaccine

Introduction

COVID-19 vaccines became a relevant element of prevention during COVID-19 pandemic. It is worth highlighting the importance of severe allergic post-vaccination reactions.

Aim

To evaluate the usability of skin reaction tests using skin prick tests with Comirnaty (Pfizer, USA) vaccine in risk detection of the post-vaccine immediate hypersensitivity reaction (anaphylaxis) after administration of this vaccine [PvIHR(A)].

Material and methods

The analysis embraces 102 people, 85 women and 17 men with a history of immediate hypersensitivity (anaphylaxis) [IHR(A)]. Detailed medical history was collected and skin prick tests were made among participants. The positive and negative test results were illustrated in Figure 1.

Results

As it stands in Table 1, considering all participants of the study, a positive result of the skin prick tests was obtained only in 2 cases, a negative result in 99 and 1 result was questionable. The two positive results were found in participants from a group with a previous PvIHR(A) in their past medical history and they decided not to get vaccinated. The one questionable result was of a person that had PvIHR(A) after administration of the first dose of Comirnaty vaccine (Pfizer, USA). This person decided to get vaccinated again and there was no PvIHR(A) observed.

Conclusions

COVID-19 vaccination involves a low risk of anaphylaxis. Purposefulness of providing the skin prick tests using the mRNA vaccine is questionable, due to their low sensitivity and low specificity.

Endotyping of IgE-Mediated Polyethylene Glycol and/or Polysorbate 80 Allergy

BACKGROUND

Polyethylene glycol (PEG) and polysorbate 80 (PS80) allergy preclude from SARS-CoV-2 vaccination. The mechanism(s) governing cross-reactivity and PEG molecular weight dependence remain unclear.

OBJECTIVES

To evaluate PEGylated lipid nanoparticle (LNP) vaccine (BNT162b2) tolerance and explore the mechanism of reactivity in PEG and/or PS80 allergic patients.

METHODS

PEG/PS80 dual- (n = 3), PEG mono- (n = 7), and PS80 mono-allergic patients (n = 2) were included. Tolerability of graded vaccine challenges was assessed. Basophil activation testing on whole blood (wb-BAT) or passively sensitized donor basophils (allo-BAT) was performed using PEG, PS80, BNT162b2, and PEGylated lipids (ALC-0159). Serum PEG-specific IgE was measured in patients (n = 10) and controls (n = 15).

RESULTS

Graded BNT162b2 challenge in dual- and PEG mono-allergic patients (n = 3/group) was well tolerated and induced anti-spike IgG seroconversion. PS80 mono-allergic patients (n = 2/2) tolerated single-dose BNT162b2 vaccination. Wb-BAT reactivity to PEG-containing antigens was observed in dual- (n = 3/3) and PEG mono- (n = 2/3), but absent in PS80 mono-allergic patients (n = 0/2). BNT162b2 elicited the highest in vitro reactivity. BNT162b2 reactivity was IgE mediated, complement independent, and inhibited in allo-BAT by preincubation with short PEG motifs, or detergent-induced LNP degradation. PEG-specific IgE was only detectable in dual-allergic (n = 3/3) and PEG mono-allergic (n = 1/6) serum.

CONCLUSION

PEG and PS80 cross-reactivity is determined by IgE recognizing short PEG motifs, whereas PS80 mono-allergy is PEG-independent. PS80 skin test positivity in PEG allergics was associated with a severe and persistent phenotype, higher serum PEG-specific IgE levels, and enhanced BAT reactivity. Spherical PEG exposure via LNP enhances BAT sensitivity through increased avidity. All PEG and/or PS80 excipient allergic patients can safely receive SARS-CoV-2 vaccines.

Liquid Chromatography Methods for Analysis of mRNA Poly(A) Tail Length and Heterogeneity

Messenger RNA (mRNA) is a new class of therapeutic compounds. The current advances in mRNA technology require the development of efficient analytical methods. In this work, we describe the development of several methods for measurement of mRNA poly(A) tail length and heterogeneity. Poly(A) tail was first cleaved from mRNA with the RNase T1 enzyme. The average length of a liberated poly(A) tail was analyzed with the size exclusion chromatography method. Size heterogeneity of the poly(A) tail was estimated with high-resolution ion-pair reversed phase liquid chromatography (IP RP LC). The IP RP LC method provides resolution of poly(A) tail oligonucleotide variants up to 150 nucleotide long. Both methods use a robust ultraviolet detection suitable for mRNA analysis in quality control laboratories. The results were confirmed by the LC-mass spectrometry (LC MS) analysis of the same mRNA sample. The poly(A) tail length and heterogeneity results were in good agreement.

Alkyne as a Latent Warhead to Covalently Target SARS-CoV-2 Main Protease

There is an urgent need for improved therapy to better control the ongoing COVID-19 pandemic. The main protease Mpro plays a pivotal role in SARS-CoV-2 replications, thereby representing an attractive target for antiviral development. We seek to identify novel electrophilic warheads for efficient, covalent inhibition of Mpro. By comparing the efficacy of a panel of warheads installed on a common scaffold against Mpro, we discovered that the terminal alkyne could covalently modify Mpro as a latent warhead. Our biochemical and X-ray structural analyses revealed the irreversible formation of the vinyl-sulfide linkage between the alkyne and the catalytic cysteine of Mpro. Clickable probes based on the alkyne inhibitors were developed to measure target engagement, drug residence time, and off-target effects. The best alkyne-containing inhibitors potently inhibited SARS-CoV-2 infection in cell infection models. Our findings highlight great potentials of alkyne as a latent warhead to target cystine proteases in viruses and beyond.

The clinical progress and challenges of mRNA vaccines

Owing to the breakthroughs in the prevention and control of the COVID-19 pandemic, messenger RNA (mRNA)-based vaccines have emerged as promising alternatives to conventional vaccine approaches for infectious disease prevention and anticancer treatments. Advantages of mRNA vaccines include flexibility in designing and manipulating antigens of interest, scalability in rapid response to new variants, ability to induce both humoral and cell-mediated immune responses, and ease of industrialization. This review article presents the latest advances and innovations in mRNA-based vaccines and their clinical translations in the prevention and treatment of infectious diseases or cancers. We also highlight various nanoparticle delivery platforms that contribute to their success in clinical translation. Current challenges related to mRNA immunogenicity, stability, and in vivo delivery and the strategies for addressing them are also discussed. Finally, we provide our perspectives on future considerations and opportunities for applying mRNA vaccines to fight against major infectious diseases and cancers. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Biology-Inspired Nanomaterials > Lipid-Based Structures.

In Vitro Antibody-Dependent Enhancement of SARS-CoV-2 Infection Could Be Abolished by Adding Human IgG

Evidence of antibody-dependent enhancement (ADE) of other viruses has raised concerns about the safety of SARS-CoV-2 vaccines and antibody therapeutics. In vitro studies have shown ADE of SARS-CoV-2 infection. In this study, we also found that vaccination/convalescent sera and some approved monoclonal antibodies can enhance SARS-CoV-2 infection of FcR-expressing B cells in vitro. However, the enhancement of SARS-CoV-2 infection can be prevented by blocking Fc-FcR interaction through the addition of human serum/IgG or the introduction of mutations in the Fc portion of the antibody. It should be noted that ADE activity observed on FcR-expressing cells in vitro may not necessarily reflect the situation in vivo; therefore, animal and clinical data should be included for ADE evaluation.

Engineering Materials and Devices for the Prevention, Diagnosis, and Treatment of COVID-19 and Infectious Diseases

Following the global spread of COVID-19, scientists and engineers have adapted technologies and developed new tools to aid in the fight against COVID-19. This review discusses various approaches to engineering biomaterials, devices, and therapeutics, especially at micro and nano levels, for the prevention, diagnosis, and treatment of infectious diseases, such as COVID-19, serving as a resource for scientists to identify specific tools that can be applicable for infectious-disease-related research, technology development, and treatment. From the design and production of equipment critical to first responders and patients using three-dimensional (3D) printing technology to point-of-care devices for rapid diagnosis, these technologies and tools have been essential to address current global needs for the prevention and detection of diseases. Moreover, advancements in organ-on-a-chip platforms provide a valuable platform to not only study infections and disease development in humans but also allow for the screening of more effective therapeutics. In addition, vaccines, the repurposing of approved drugs, biomaterials, drug delivery, and cell therapy are promising approaches for the prevention and treatment of infectious diseases. Following a comprehensive review of all these topics, we discuss unsolved problems and future directions.

Optimization of an alum-anchored clinical HIV vaccine candidate

In the ongoing effort to develop a vaccine against HIV, vaccine approaches that promote strong germinal center (GC) responses may be critical to enable the selection and affinity maturation of rare B cell clones capable of evolving to produce broadly neutralizing antibodies. We previously demonstrated an approach for enhancing GC responses and overall humoral immunity elicited by alum-adjuvanted protein immunization via the use of phosphoserine (pSer) peptide-tagged immunogens that stably anchor to alum particles via ligand exchange with the alum particle surface. Here, using a clinically relevant stabilized HIV Env trimer termed MD39, we systematically evaluated the impact of several parameters relevant to pSer tag composition and trimer immunogen design to optimize this approach, including phosphate valency, amino acid sequence of the trimer C-terminus used for pSer tag conjugation, and structure of the pSer tag. We also tested the impact of co-administering a potent saponin/monophosphoryl lipid A (MPLA) nanoparticle co-adjuvant with alum-bound trimers. We identified MD39 trimer sequences bearing an optimized positively-charged C-terminal amino acid sequence, which, when conjugated to a pSer tag with four phosphates and a polypeptide spacer, bound very tightly to alum particles while retaining a native Env-like antigenicity profile. This optimized pSer-trimer design elicited robust antigen-specific GC B cell and serum IgG responses in mice. Through this optimization, we present a favorable MD39-pSer immunogen construct for clinical translation.

mRNA vaccine in cancer therapy: Current advance and future outlook

Messenger ribonucleic acid (mRNA) vaccines are a relatively new class of vaccines that have shown great promise in the immunotherapy of a wide variety of infectious diseases and cancer. In the past 2 years, SARS-CoV-2 mRNA vaccines have contributed tremendously against SARS-CoV2, which has prompted the arrival of the mRNA vaccine research boom, especially in the research of cancer vaccines. Compared with conventional cancer vaccines, mRNA vaccines have significant advantages, including efficient production of protective immune responses, relatively low side effects and lower cost of acquisition. In this review, we elaborated on the development of cancer vaccines and mRNA cancer vaccines, as well as the potential biological mechanisms of mRNA cancer vaccines and the latest progress in various tumour treatments, and discussed the challenges and future directions for the field.

Comparison of medium-term adverse reactions induced by the first and second dose of mRNA BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine: a post-marketing Italian study conducted between 1 January and 28 February 2021

OBJECTIVES

On 21 December 2020 the European Commission granted conditional marketing authorisation in the European Union for the anti-COVID-19 mRNA vaccine Bnt162b2 (Comirnaty, Pfizer/BioNTech). The main endpoint of this epidemiological, observational, prospective and monocentric study was to identify the number, types, and severity of adverse events following immunisation that occurred in subjects who had been previously infected with COVID-19, and in those who had not, after vaccination with Comirnaty, and to compare the two groups of subjects looking at events that occurred within a month after the first and the second dose.

METHODS

Data were gathered by a questionnaire. The results included the responses of all healthcare workers (2030) of the IRCCS Sacro Cuore Don Calabria Hospital (Italy) vaccinated between 1st January and 28th February 2021. Adverse effects of the vaccine were reported after the first and the second doses.

RESULTS

There was a statistically significant increase (p<0.001, χ2=35.60) in participants who experienced some side-effects after receiving the first dose of the vaccine and who had previously been infected with the coronavirus, compared with participants who had not previously been infected. 46.76% (136) of the participants who had previously been infected experienced some side-effects after the first dose of vaccine, and 63.23% (184) experienced some side-effects after the second dose, compared with 29.15% (507) after the first dose and 70.79% (1231) after the second dose in those who had not been previously infected. The number of participants who experienced side-effects after the second dose and had previously been infected was significantly lower compared with participants who had not previously been infected (p=0.0094, χ2=6.743).

CONCLUSIONS

Most of the side-effects identified in this trial were also reported by the manufacturer and the US Food and Drug Administration. Active surveillance should always continue to constantly check the vaccine's risk/benefit ratio over time.

Recent Advances in Site-Specific Lipid Nanoparticles for mRNA Delivery

The success of mRNA vaccines during the COVID-19 pandemic has greatly accelerated the development of mRNA therapy. mRNA is a negatively charged nucleic acid that serves as a template for protein synthesis in the ribosome. Despite its utility, the instability of mRNA requires suitable carriers for in vivo delivery. Lipid nanoparticles (LNPs) are employed to protect mRNA from degradation and enhance its intracellular delivery. To further optimize the therapeutic efficacy of mRNA, site-specific LNPs have been developed. Through local or systemic administration, these site-specific LNPs can accumulate in specific organs, tissues, or cells, allowing for the intracellular delivery of mRNA to specific cells and enabling the exertion of local or systemic therapeutic effects. This not only improves the efficiency of mRNA therapy but also reduces off-target adverse effects. In this review, we summarize recent site-specific mRNA delivery strategies, including different organ- or tissue-specific LNP after local injection, and organ-specific or cell-specific LNP after intravenous injection. We also provide an outlook on the prospects of mRNA therapy.

A practical guide to address reactions to vaccines in children

Currently available vaccines are safe, but, potentially, any vaccine can cause an allergic reaction and, albeit very rare, anaphylaxis can occur. Although its rarity, the precise diagnostic management of a suspected anaphylaxis postvaccination is of paramount importance due to the risk of a potentially serious reaction after re-exposure, while a misdiagnosis might lead to an increase in the number of children that interrupt vaccinations resulting in an unjustifiably individual and collective risk of loss of protection against immune preventable diseases. In the light that most cases of suspected allergy to a vaccine are not effectively confirmed in up to 85% of the cases referred for an allergy evaluation, patients can continue the vaccination schedule with the same formulation and tolerance of the booster doses. The patient assessment has to be done by an expert in the vaccine field, usually an allergist or an immunologist depending on the country, to select subjects at risk of allergic reactions and to perform the correct procedures for vaccine hypersensitivity diagnosis and management, in order to guarantee safe immunization practices. The aim of this review is to provide a practical guidance for the safe management of allergic children undergoing immunization procedures. The guide is referred both to the evaluation of children who have previously experienced a suspected allergic reaction to a specific vaccine and their management in case of further booster doses, and to children allergic to a component of the vaccine to be administered.

Anaphylatoxin Complement 5a in Pfizer BNT162b2-Induced Immediate-Type Vaccine Hypersensitivity Reactions

The underlying immunological mechanisms of immediate-type hypersensitivity reactions (HSR) to COVID-19 vaccines are poorly understood. We investigate the mechanisms of immediate-type hypersensitivity reactions to the Pfizer BNT162b2 vaccine and the response of antibodies to the polyethylene glycol (PEG)ylated lipid nanoparticle after two doses of vaccination. Sixty-seven participants, median age 35 and 77.3% females who tolerated two doses of the BNT162b2 vaccine (non-reactors), were subjected to various blood-sampling time points. A separate group of vaccine reactors (10 anaphylaxis and 37 anonymised tryptase samples) were recruited for blood sampling. Immunoglobulin (Ig)G, IgM and IgE antibodies to the BNT162b2 vaccine, biomarkers associated with allergic reaction, including tryptase for anaphylaxis, complement 5a(C5a), intercellular adhesion molecule 1 (ICAM-1) for endothelial activation and Interleukin (IL)-4, IL-10, IL-33, tumour necrosis factor (TNF) and monocyte chemoattractant protein (MCP-1), were measured. Basophil activation test (BAT) was performed in BNT162b2-induced anaphylaxis patients by flow cytometry. The majority of patients with immediate-type BNT162b2 vaccine HSR demonstrated raised C5a and Th2-related cytokines but normal tryptase levels during the acute reaction, together with significantly higher levels of IgM antibodies to the BNT162b2 vaccine (IgM 67.2 (median) vs. 23.9 AU/mL, p < 0.001) and ICAM-1 when compared to non-reactor controls. No detectable IgE antibodies to the BNT162b2 vaccine were found in these patients. The basophil activation tests by flow cytometry to the Pfizer vaccine, 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol (DMG-PEG) and PEG-2000 were negative in four anaphylaxis patients. Acute hypersensitivity reactions post BNT162b2 vaccination suggest pseudo-allergic reactions via the activation of anaphylatoxins C5a and are independent of IgE-mechanisms. Vaccine reactors have significantly higher levels of anti-BNT162b2 IgM although its precise role remains unclear.

RNA Therapeutics: A Healthcare Paradigm Shift

COVID-19 brought about the mRNA vaccine and a paradigm shift to a new mode of treating and preventing diseases. Synthetic RNA products are a low-cost solution based on a novel method of using nucleosides to act as an innate medicine factory with unlimited therapeutic possibilities. In addition to the common perception of vaccines preventing infections, the newer applications of RNA therapies include preventing autoimmune disorders, such as diabetes, Parkinson's disease, Alzheimer's disease, and Down syndrome; now, we can deliver monoclonal antibodies, hormones, cytokines, and other complex proteins, reducing the manufacturing hurdles associated with these products. Newer PCR technology removes the need for the bacterial expression of DNA, making mRNA a truly synthetic product. AI-driven product design expands the applications of mRNA technology to repurpose therapeutic proteins and test their safety and efficacy quickly. As the industry focuses on mRNA, many novel opportunities will arise, as hundreds of products under development will bring new perspectives based on this significant paradigm shift-finding newer solutions to existing challenges in healthcare.

Antibodies against Poly(ethylene glycol) Activate Innate Immune Cells and Induce Hypersensitivity Reactions to PEGylated Nanomedicines

Nanomedicines and macromolecular drugs can induce hypersensitivity reactions (HSRs) with symptoms ranging from flushing and breathing difficulties to hypothermia, hypotension, and death in the most severe cases. Because many normal individuals have pre-existing antibodies that bind to poly(ethylene glycol) (PEG), which is often present on the surface of nanomedicines and macromolecular drugs, we examined if and how anti-PEG antibodies induce HSRs to PEGylated liposomal doxorubicin (PLD). Anti-PEG IgG but not anti-PEG IgM induced symptoms of HSRs including hypothermia, altered lung function, and hypotension after PLD administration in C57BL/6 and nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Hypothermia was significantly reduced by blocking FcγRII/III, by depleting basophils, monocytes, neutrophils, or mast cells, and by inhibiting secretion of histamine and platelet-activating factor. Anti-PEG IgG also induced hypothermia in mice after administration of other PEGylated liposomes, nanoparticles, or proteins. Humanized anti-PEG IgG promoted binding of PEGylated nanoparticles to human immune cells and induced secretion of histamine from human basophils in the presence of PLD. Anti-PEG IgE could also induce hypersensitivity reactions in mice after administration of PLD. Our results demonstrate an important role for IgG antibodies in induction of HSRs to PEGylated nanomedicines through interaction with Fcγ receptors on innate immune cells and provide a deeper understanding of HSRs to PEGylated nanoparticles and macromolecular drugs that may facilitate development of safer nanomedicines.

Real-life safety profile of mRNA vaccines for COVID-19: an analysis of VAERS database

Introduction

Since the first COVID-19 messenger RNA vaccines became available globally for emergency or conditional use, post-marketing surveillance activities have been implemented for the monitoring of any adverse events that might arise in daily clinical practice and were not detected earlier during clinical trials.

Methods

Safety data concerning the BNT162b2 and the mRNA-1273 COVID-19 vaccines were collected from the Vaccine Adverse Event Reporting System (VAERS) for the period from December 2020 to October 15, 2021. In addition to a descriptive analysis of individuals who experienced an adverse event after vaccination, a case-non-case analysis was performed by using the Reporting Odds Ratio with 95% confidence interval as statistical parameter for detecting differences in reporting rates between the two mRNA vaccines.

Results

At the cut-off date, a total of 758,040 reports were submitted to VAERS, of which 439,401 were related to the Pfizer-BioNTech (BNT162b2) vaccine and 318,639 to the Moderna vaccine (mRNA-1273). Most common adverse events following immunization for both mRNA vaccines were headache, fatigue, pyrexia, dizziness, nausea, pain, chills, and pain in extremity. A disproportionality was found for BNT162b2 as compared with mRNA-1273 for some events of special interest, such as myocarditis [ROR 2.00; 95% confidence interval (CI), 1.93 to 2.06], Bell’s palsy (1.34; 1.29 to 1.39), and anaphylactic shock (3.23; 2.96 to 3.53).

Conclusion

Even if some rare adverse events were identified, our survey of post-marketing surveillance has provided further evidence of the favourable safety profile of mRNA vaccines.

Association of death or illness from COVID-19 among family and friends on vaccine uptake within four months of the Emergency Use Authorization. Findings from a national survey in the United States

OBJECTIVE

To examine the relationship between knowing that a friend or family member became ill with, or died from, COVID-19 and receiving a vaccine dose within four months of the FDA's Emergency Use Authorization.

METHODS

A national sample of 1,517 respondents were surveyed from April 7 to April 12, 2021, 1,193 of whom were eligible for the vaccine when the data were collected.

RESULTS

Respondents who knew someone who became ill with COVID-19 (AOR = 2.32, 95 % CI 1.74-3.09) or knew someone who died (AOR = 2.29, 95 % CI 1.32-3.99) from COVID-19 were more likely to receive at least a single COVID-19 vaccine dose.

CONCLUSION

Encouraging people to share their COVID-19 illness and bereavement experiences with their local network such as friends, families, social-networks and via social media might help increase vaccine uptake.

Administration of the Second Dose of mRNA COVID-19 Vaccine to a Woman With Immediate Reaction to the First Dose

Vaccines constitute the most effective public health intervention as they prevent the spread of infectious diseases and reduce disease severity and mortality. Allergic reactions can occur during vaccination. Systemic anaphylaxis is a severe, life-threatening allergic reaction which can rarely occur after vaccination. There is limited data suggesting that the majority of the patients with immediate and potentially allergic reactions after the first dose of coronavirus disease 2019 (COVID-19) can receive the second dose. A 39-year-old woman was admitted to our department after presenting anaphylactic reaction following the first dose of mRNA COVID-19 vaccine (BNT162b2). A few days later, she contacted our department and was admitted for an allergy work-up on mRNA COVID-19 vaccine and its compound polyethylene glycol (PEG). Thereafter, she completed the vaccination procedure having received pretreatment under our guidance. Confirmed allergic reactions to vaccines are customarily attributed to the inactive ingredients, or excipients like PEG and polysorbate. The latest are used to improve water-solubility in vaccines. PEG itself has not been previously used in a vaccine but polysorbate has been identified as a rare cause of allergic reactions to vaccines. It has been reported that the interaction of the immune system with lipidic nanoparticle therapeutics could result in hypersensitivity reactions (HSRs), referred to as complement activation related pseudoallergy (CARPA), which is classified as non-IgE-mediated pseudoallergy caused by the activation of the complement system.

COVID-19 Therapeutics: Use, Mechanism of Action, and Toxicity (Vaccines, Monoclonal Antibodies, and Immunotherapeutics)

SARS-CoV-2 emerged in December 2019 and led to the COVID-19 pandemic. Efforts to develop therapeutics have led to innovations such as mRNA vaccines and oral antivirals. Here we provide a narrative review of the biologic therapeutics used or proposed to treat COVID-19 during the last 3 years. This paper, along with its companion that covers xenobiotics and alternative remedies, is an update to our 2020 paper. Monoclonal antibodies prevent progression to severe disease, are not equally effective across variants, and are associated with minimal and self-limited reactions. Convalescent plasma has side effects like monoclonal antibodies, but with more infusion reactions and less efficacy. Vaccines prevent progression for a larger part of the population. DNA and mRNA vaccines are more effective than protein or inactivated virus vaccines. After mRNA vaccines, young men are more likely to have myocarditis in the subsequent 7 days. After DNA vaccines, those aged 30-50 are very slightly more likely to have thrombotic disease. To all vaccines we discuss, women are slightly more likely to have an anaphylactic reaction than men, but the absolute risk is small.

mRNA COVID-19 Vaccine Anaphylaxis: Epidemiology, Risk Factors, and Evaluation

PURPOSE OF REVIEW

The COVID-19 vaccines have proved essential in our defense against the COVID-19 pandemic. However, concerns regarding allergic reactions to the vaccines persist to this day. Herein, we review the data regarding the frequency of allergic reactions to the COVID-19 vaccines, the epidemiology, and the management of patients reporting vaccine allergic reactions.

RECENT FINDINGS

Although initial reports emphasized a high risk of anaphylaxis to the COVID-19 vaccines, more recent data demonstrate similar rates of anaphylaxis to the COVID-19 vaccines as to other vaccines. Alternative explanations for increased rates of apparent allergic reactions are discussed, including the role for stress-related and nocebo responses. COVID-19 vaccines and mRNA vaccine technology are overwhelmingly safe and well-tolerated by most patients. Careful history and case review will enable the discerning physician to safely vaccinate most patients. Rare patients with objective signs and symptoms of anaphylaxis may be candidates for alternatives to vaccination including monoclonal antibodies.

Medicinal chemistry insights into antiviral peptidomimetics

The (re)emergence of multidrug-resistant viruses and the emergence of new viruses highlight the urgent and ongoing need for new antiviral agents. The use of peptidomimetics as therapeutic drugs has often been associated with advantages, such as enhanced binding affinity, improved metabolic stability, and good bioavailability profiles. The development of novel antivirals is currently driven by strategies of converting peptides into peptidomimetic derivatives. In this review, we outline different structural modification design strategies for developing novel peptidomimetics as antivirals, involving N- or C-cap terminal structure modifications, pseudopeptides, amino acid modifications, inverse-peptides, cyclization, and molecular hybridization. We also present successful recent examples of peptidomimetic designs.

Assemblies of poly(N-vinyl-2-pyrrolidone)-based double hydrophilic block copolymers triggered by lanthanide ions: characterization and evaluation of their properties as MRI contrast agents

Because of the formation of specific antibodies to poly(ethylene glycol) (PEG) leading to life-threatening side effects, there is an increasing need to develop alternatives to treatments and diagnostic methods based on PEGylated copolymers. Block copolymers comprising a poly(N-vinyl-2-pyrrolidone) (PVP) segment can be used for the design of such vectors without any PEG block. As an example, a poly(acrylic acid)-block-poly(N-vinyl-2-pyrrolidone) (PAA-b-PVP) copolymer with controlled composition and molar mass is synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Mixing this copolymer with lanthanide cations (Gd³⁺, Eu³⁺, Y³⁺) leads to the formation of hybrid polyion complexes with increased stability, preventing the lanthanide cytotoxicity and in vitro cell penetration. These new nanocarriers exhibit enhanced T₁ MRI contrast, when intravenously administered into mice. No leaching of gadolinium ions is detected from such hybrid complexes.

Race with virus evolution: The development and application of mRNA vaccines against SARS-CoV-2

Since the COVID-19 pandemic was declared, vaccines against SARS-CoV-2 have been urgently developed around the world. On the basis of the mRNA vaccine technology developed previously, COVID-19 mRNA vaccines were promptly tested in animals, advanced to clinical trials, and then authorized for emergency use in humans. The administration of COVID-19 mRNA vaccines has successfully reduced the hospitalization and mortality caused by the viral infection, although the virus continuously evolves with its transmission. Therefore, the development of mRNA vaccine technology, including RNA modification and delivery systems, is well recognized for its contribution to moderating the harms caused by the COVID-19 pandemic. The scientists who developed these technologies, Katalin Karikó, Drew Weissman, and Pieter Cullis, were awarded the 2022 Tang Prize in Biopharmaceutical Science. In this review, we summarize the principles, safety and efficacy of as well as the immune response to COVID-19 mRNA vaccines. Since mRNA vaccine approaches could be practical for the prevention of infectious diseases, we also briefly describe mRNA vaccines against other human viral pathogens in clinical trials.

Pattern of self-reported adverse events related to COVID-19 vaccines in Saudi Arabia: A nationwide study

Background

Vaccination against coronavirus disease 2019 (COVID-19) is the most effective way to end the pandemic. Any development of adverse events (AEs) from various vaccines should be reported. We therefore aimed to explore major and minor AEs among vaccinated individuals in Saudi Arabia.

Methods

This is a nationwide report based on the Saudi Arabian Ministry of Health (MOH) registry. It included those who received COVID-19 vaccines from 17th December 2020 to 31st December 2021. The study included spontaneous self-reported adverse effects to COVID-19 vaccines where the study participants used a governmental mobile app (Sehhaty) to report their AEs following vaccination using a checklist option that included a selection of side-effects. The primary outcome was to determine AEs reported within 14 days of vaccination which included injection site itching, pain, reaction, redness, swelling, anxiety, dizziness, fever, headache, hoarseness, itchiness, loss of consciousness, nausea, heartburn, sleep disruption, fatigue, seizures, anaphylaxis, shortness of breath, wheezing, swelling of lips, face, and throat, loss of consciousness, and admissions into the intensive care unit (ICU).

Results

The study included a total number of 28,031 individuals who reported 71,480 adverse events (AEs); which were further classified into minor and major adverse events including ICU admissions post vaccination. Of the reported AEs, 38,309 (53. 6%) side-effects were reported following Pfizer-BioNTech, 32,223 (45%) following Oxford-AstraZeneca, and 948 (1.3%) following Moderna. The following reported AEs were statistically significant between the different vaccine types: shortness of breath\difficulty of breathing, dizziness, fever above 39°C, headache, hoarseness, injection site reactions, itchiness, nausea, sleep disruption, fatigue, wheezing, swelling of lips/face and\or throat, and loss of consciousness (p-value < 0.05). Fever and seizure were the only statistically significant AEs amongst the number of vaccine doses received (p-value < 0.05). Ten ICU admissions were reported in the 14 days observation period post-COVID-19 vaccination with the following diagnoses: acute myocardial infarction, pneumonia, atherosclerosis, acute respiratory failure, intracranial hemorrhage, grand mal seizure, Guillain-Barré syndrome, abnormal blood gas levels, and septic shock.

Conclusion

This study demonstrated that the most prevalent SARS-CoV-2 vaccine side-effects among adults in Saudi Arabia were mild in nature. This information will help reduce vaccine hesitancy and encourage further mass vaccination to combat the COVID-19 pandemic, especially as booster doses are now available. Further studies are warranted to obtain a better understanding of the association between risk factors and the experiencing of side-effects post vaccination.

Anaphylaxis: Advances in the Past 10 Years

In the past 10 years, anaphylaxis has grown into its own special area of study within Allergy-Immunology, both at the bench and at the bedside. This review focuses on some of the most clinically relevant advances over the past decade. These include simplified and more inclusive diagnostic criteria for adults and children, uniform definition of biphasic anaphylaxis, and improved systems for objective severity grading. Studies reported in the past decade have led to improved understanding of normal and abnormal regulation of mast cell function, translating into better diagnostic and therapeutic approaches to patients with anaphylaxis. Research has provided improved recognition and treatment of mast cell disorders and has identified a new condition, hereditary α-tryptasemia, that may impact anaphylactic syndromes. We have learned to recognize new causes (α-gal), new pathways (Mas-related G protein-coupled receptor-X2), and many risk factors for severe anaphylaxis. The stability of epinephrine in autoinjectors was reported to be very good for several years after the labeled expiry date, and it can tolerate freezing and thawing. Repeated and prolonged exposure to excessive heat leads to degradation of epinephrine activity. New treatments to prevent severe anaphylaxis have been described, using new ways to block the IgE receptor or modulate intracellular signaling pathways.

Utilizing Biologics in Drug Desensitization

PURPOSE OF REVIEW

The purpose of this literature review was to review the latest advancements with biologics in rapid drug desensitization. Our methodology was to highlight both desensitization to biologics themselves and the use of biologics in desensitization to both biologic and nonbiologic drugs.

RECENT FINDINGS

Biologics are a vast category of drugs that include monoclonal antibodies, nanobodies, modern vaccinations, and even hormones. Desensitization to biologics can be safely performed through standardized procedure. Biomarkers are used both in vitro and in vivo to help identify and classify hypersensitivity reactions. Hypersensitivity reactions to the mRNA vaccinations against SARS-CoV-2 present their own unique challenges to management. There are specific excipients in monoclonal antibodies that are thought to be responsible for many of their hypersensitivity reactions. Certain biologics can even be used to assist in desensitization to other drugs. Rapid drug desensitization is a standardized procedure that may be able to help many patients who have experienced hypersensitivity reactions to biologics and would best be treated with them to continue to receive them. Biologic drugs have opened a new era in medicine for the prevention and treatment of infectious diseases, cancer, and inflammatory diseases. Hypersensitivity reactions to biologics are quite common. This literature review presents the latest advancements in our understanding of hypersensitivity reactions to biologics, how rapid drug desensitization can be used to continue therapy despite history of hypersensitivity, and how biologics themselves can be used to aid in desensitization itself.

COVID-19 vaccine provocation test outcome in high-risk allergic patients: A retrospective study from a tertiary hospital in Indonesia

Background

High COVID-19 vaccine coverage is essential. Patients who are considered high risk for hypersensitivity reactions and have had an allergic reaction to the COVID-19 vaccine are usually referred to an allergist for assessment of vaccination. Administration of a vaccine graded challenge (also known as a provocation test) is an option that can be considered in this population. This primary objective of this study is to describe the outcome of the COVID-19 vaccine provocation test and to understand the predicting factors associated with hypersensitivity reaction after the provocation test as the secondary objective.

Methods

Adult patients with a history of hypersensitivity reaction to the first COVID-19 vaccine and high-allergic patients who underwent COVID-19 vaccine provocation test up until May 2022 were included. A protocol using skin prick test (SPT), intradermal test (IDT), followed by graded challenge was developed for the determined vaccine used.

Results

A total of 232 patients were included in the analysis. Twenty-eight had hypersensitivity to their first COVID-19 vaccine dose and 204 were high risk for allergic reaction. Hypersensitivity reactions occurred in 20 patients (8.6%, 95% CI: 5-12.2%), consisting of 4 reactions after SPT, 9 after IDT, 7 during or after titrated challenge. Half of the reactions were mild; however, 3 patients developed severe reactions. Patients with history of anaphylaxis were more likely to experience hypersensitivity reaction after provocation test (aRR = 2.79, 95% CI: 1.05-7.42).

Conclusion

Provocation test in COVID-19 vaccination has a high success rate in patients with a history of hypersensitivity to the first COVID-19 vaccine and in high allergic patients. History of anaphylaxis is associated with hypersensitivity reaction after a COVID-19 vaccine provocation test.

Case Report: A case of multisystem inflammatory syndrome in an 11-year-old female after COVID-19 inactivated vaccine

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory, multisystem syndrome temporally associated with SARS-CoV-2, is a rare but serious complication of SARS-CoV-2 infection in children that typically occurs 2-6 weeks after SARS-CoV-2 infection. The pathophysiology of MIS-C is unknown. MIS-C, first recognized in April 2020, is characterized by fever, systemic inflammation, and multi-system organ involvement. Post-vaccination adverse effects have increased with COVID-19 vaccinations, and MIS linked to immunization with COVID-19 vaccines has also been observed.

CASE REPORT

An 11-year-old Chinese girl presented with a high-grade fever, rash, and dry cough for 2 days. She had her 2nd SARS-CoV-2 inactivated vaccination dose five days before hospital admission. On day 3 & 4, she experienced bilateral conjunctivitis, hypotension (66/47 mmHg), and a high CRP level. She was diagnosed with MIS-C. The patient's condition deteriorated rapidly, necessitating intensive care unit admission. The patient's symptoms improved after intravenous immunoglobulin, methylprednisolone, and oral aspirin therapy. She was discharged from the hospital after 16 days as her general condition, and laboratory biomarkers returned to normal.

CONCLUSION

Inactivated Covid-19 vaccination might trigger MIS-C. Further research is needed to evaluate whether a correlation exists between COVID-19 vaccination and MIS-C development.

Tuning the immune response: sulfated archaeal glycolipid archaeosomes as an effective vaccine adjuvant for induction of humoral and cell-mediated immunity towards the SARS-CoV-2 Omicron variant of concern

Liposomes composed of sulfated lactosyl archaeol (SLA) have been shown to be a safe and effective vaccine adjuvant with a multitude of antigens in preclinical studies. In particular, SLA-adjuvanted SARS-CoV-2 subunit vaccines based on trimeric spike protein antigens were shown to be immunogenic and efficacious in mice and hamsters. With the continued emergence of SARS-CoV-2 variants, we sought to evaluate next-generation vaccine formulations with an updated antigenic identity. This was of particular interest for the widespread Omicron variant, given the abundance of mutations and structural changes observed within its spike protein compared to other variants. An updated version of our resistin-trimerized SmT1 corresponding to the B.1.1.529 variant was successfully generated in our Chinese Hamster Ovary (CHO) cell-based antigen production platform and characterized, revealing some differences in protein profile and ACE2 binding affinity as compared to reference strain-based SmT1. We next evaluated this Omicron-based spike antigen for its immunogenicity and ability to generate robust antigen-specific immune responses when paired with SLA liposomes or AddaS03 (a mimetic of the AS03 oil-in-water emulsion adjuvant system found in commercialized SARS-CoV-2 protein vaccines). Immunization of mice with vaccine formulations containing this updated antigen with either adjuvant stimulated neutralizing antibody responses favouring Omicron over the reference strain. Cell-mediated responses, which play an important role in the neutralization of intracellular infections, were induced to a much higher degree with the SLA adjuvant relative to the AddaS03-adjuvanted formulations. As such, updated vaccines that are better capable of targeting towards SARS-CoV-2 variants can be generated through an optimized combination of antigen and adjuvant components.

Vaccine Side Effects in Health Care Workers after Vaccination against SARS-CoV-2: Data from TüSeRe:exact Study

As the Corona Disease 2019 (COVID-19) caused by SARS-CoV-2 persists, vaccination is one of the key measures to contain the spread. Side effects (SE) from vaccination are one of the reasons for reluctance to vaccinate. We systematically investigated self-reported SE after the first, second, and booster vaccinations. The data were collected during the TüSeRe: exact study (Tübinger Monitoring Studie zur exakten Analyse der Immunantwort nach Vakzinierung). Employees of health and research institutions were invited to participate. Study participants were asked to fill out an online questionnaire and report their SE after each dose of SARS-CoV-2 vaccination. A total of 1046 participants (mean age: 44 ± 12.9 years; female, n = 815 (78%); male, n = 231 (22%)) were included in the analysis. Local and systemic SE were more frequent after receiving the vector-based vaccine ChAdOx1 nCoV-19 in the first vaccination. However, local and systemic SE were more common after receiving mRNA vaccines (BNT162b2, mRNA-1273) in the second vaccination. Compared to the BNT162b2 vaccine, more SE have been observed after receiving the mRNA-1273 vaccine in the booster vaccination. In multivariate analysis, local and systemic side effects were associated with vaccine type, age and gender. Local and systemic SE are common after SARS-CoV-2 vaccines. The frequency of self-reported local and systemic SE differ significantly between mRNA and vector-based vaccines.

AbAgIntPre: A deep learning method for predicting antibody-antigen interactions based on sequence information

Introduction

Antibody-mediated immunity is an essential part of the immune system in vertebrates. The ability to specifically bind to antigens allows antibodies to be widely used in the therapy of cancers and other critical diseases. A key step in antibody therapeutics is the experimental identification of antibody-antigen interactions, which is generally time-consuming, costly, and laborious. Although some computational methods have been proposed to screen potential antibodies, the dependence on 3D structures still limits the application of these methods.

Methods

Here, we developed a deep learning-assisted prediction method (i.e., AbAgIntPre) for fast identification of antibody-antigen interactions that only relies on amino acid sequences. A Siamese-like convolutional neural network architecture was established with the amino acid composition encoding scheme for both antigens and antibodies.

Results and Discussion

The generic model of AbAgIntPre achieved satisfactory performance with the Area Under Curve (AUC) of 0.82 on a high-quality generic independent test dataset. Besides, this approach also showed competitive performance on the more specific SARS-CoV dataset. We expect that AbAgIntPre can serve as an important complement to traditional experimental methods for antibody screening and effectively reduce the workload of antibody design. The web server of AbAgIntPre is freely available at http://www.zzdlab.com/AbAgIntPre.

Characterizing Responses to COVID-19 Vaccine Promotion on TikTok

PURPOSE

The Alabama Department of Public Health (ADPH) sponsored a TikTok contest to improve vaccination rates among young people. This analysis sought to advance understanding of COVID-19 vaccine perceptions among ADPH contestants and TikTok commenters.

APPROACH

This exploratory content analysis characterized sentiment and imagery in the TikTok videos and comments. Videos were coded by two reviewers and engagement metrics were collected for each video.

SETTING

Publicly available TikTok videos entered into ADPH's contest with the hashtags #getvaccinatedAL and #ADPH between July 16 - August 6, 2021.

PARTICIPANTS

ADPH contestants (n = 44) and TikTok comments (n = 502).

METHOD

A content analysis was conducted; videos were coded by two reviewers and engagement metrics was collected for each video (e.g., reason for vaccination, content, type of vaccination received). Video comments were analyzed using VADER, a lexicon and rule-based sentiment analysis tool).

RESULTS

Of 44 videos tagged with #getvaccinatedAL and #ADPH, 37 were related to the contest. Of the 37 videos, most cited family/friends and civic duty as their reason to get the COVID-19 vaccine. Videos were shared an average of 9 times and viewed 977 times. 70% of videos had comments, ranging from 0-61 (mean 44). Words used most in positively coded comments included, "beautiful," "smiling face emoji with 3 hearts," "masks," and "good.;" whereas words used most in negatively coded comments included "baby," "me," "chips," and "cold."

CONCLUSION

Understanding COVID-19 vaccine sentiment expressed on social media platforms like TikTok can be a powerful tool and resource for public health messaging.

Adverse Events of COVID-19 Vaccination among the Saudi Population: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to synthesize the evidence on the adverse events (AEs) of coronavirus disease 2019 (COVID-19) vaccinations in Saudi Arabia. A computerized search in MEDLINE via PubMed and OVID, Scopus, CENTRAL, and Web of Science was conducted using relevant keywords. The NIH tools were used for the quality assessment. A total of 14 studies (16 reports) were included. The pooled analysis showed that the incidence of AEs post-COVID-19 vaccination was 40.4% (95% CI:6.4% to 87%). Compared to the AstraZeneca vaccine, the Pfizer-BioNTech vaccine was associated with a lower risk ratio (RR) of wheezing (RR = 0.04), fever (RR = 0.32), chills (RR = 0.41), headache (RR = 0.47), dizziness (RR = 0.49), and joint pain (RR = 0.51). The Pfizer-BioNTech vaccine was associated with significantly higher RR of general allergic reactions (RR = 1.62), dyspnea (RR = 1.68), upper respiratory tract symptoms (RR = 1.71), and lymphadenopathy (RR = 8.32). The current evidence suggests that the incidence of AEs following COVID-19 vaccines is 40%; however, most of these AEs were mild and for a short time. The overall number of participants with AEs was higher in the Pfizer group compared to the AstraZeneca group; however, the AstraZeneca vaccine was associated with a higher RR of several AEs.

Ubiquitin variants potently inhibit SARS-CoV-2 PLpro and viral replication via a novel site distal to the protease active site

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has made it clear that combating coronavirus outbreaks benefits from a combination of vaccines and therapeutics. A promising drug target common to all coronaviruses-including SARS-CoV, MERS-CoV, and SARS-CoV-2-is the papain-like protease (PLpro). PLpro cleaves part of the viral replicase polyproteins into non-structural protein subunits, which are essential to the viral replication cycle. Additionally, PLpro can cleave both ubiquitin and the ubiquitin-like protein ISG15 from host cell substrates as a mechanism to evade innate immune responses during infection. These roles make PLpro an attractive antiviral drug target. Here we demonstrate that ubiquitin variants (UbVs) can be selected from a phage-displayed library and used to specifically and potently block SARS-CoV-2 PLpro activity. A crystal structure of SARS-CoV-2 PLpro in complex with a representative UbV reveals a dimeric UbV bound to PLpro at a site distal to the catalytic site. Yet, the UbV inhibits the essential cleavage activities of the protease in vitro and in cells, and it reduces viral replication in cell culture by almost five orders of magnitude.