Erratum: Intradermal testing with COVID-19 mRNA vaccines predicts tolerance.

[This corrects the article DOI: 10.3389/falgy.2022.818049.].

Polyethylene Glycol and Polysorbate 80 Skin Tests in the Context of an Allergic Risk Assessment for Hypersensitivity Reactions to Anti-SARS-CoV-2 mRNA Vaccines.

Concern has arisen about hypersensitivity reactions in patients with allergic reactions to drugs containing polyethylene glycol (PEG) or polysorbate 80 (PS80), excipients of currently available anti-SARS-CoV-2 mRNA vaccines. However, the actual utility of PEG and PS80 skin allergy testing is currently still debated. We retrospectively analyzed all cases of patients on whom we performed allergometric skin tests for PEG and PS80 in the context of a pre-vaccination screening (for patients with multiple hypersensitivity reactions to drugs for which these excipients were among the suspected agents) or following suspected hypersensitivity reactions to anti-SARS-CoV-2 vaccines. A total of 134 tests were performed for PEG and PS80, eight of which produced uninterpretable results (due to dermographism or non-specific reactions). Of the remaining 126 cases (85 pre-vaccinal and 41 post-vaccine reactions), 16 (12.7%) were positive for PEG and/or PS80. Stratifying by clinical indication, there were no statistically significant differences in the proportion of positive tests between patients evaluated in the context of the pre-vaccination screening and those evaluated after a vaccine reaction (10.6% vs. 17.1%, respectively, p = 0.306). Allergometric skin tests for PEG and PS80 in our case series resulted positive in an unexpectedly high proportion of patients, suggesting that testing for allergy to these two excipients should not be ignored in case of reasonable clinical suspicion.

Updated Guidance Regarding The Risk ofAllergic Reactions to COVID-19 Vaccines and Recommended Evaluation and Management: A GRADE Assessment, and International Consensus Approach.

This guidance updates 2021 GRADE recomendations regarding immediate allergic reactions following COVID-19 vaccines and addresses re-vaccinating individuals with 1st dose allergic reactions and allergy testing to determine re-vaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 re-vaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommenations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the UK, and the US formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy, and re-vaccination after a prior immediate allergic reaction. We suggest against >15-minute post-vaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest re-vaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise, in a properly equipped setting. We suggest against pre-medication, split-dosing, or special precautions because of a comorbid allergic history.

Fluctuations of Dry and Total Mass of Cells Exposed to Different Molecular Weights of Polyethylene Glycol

Polyethylene glycol (PEG) is used in many applications, and in the clinical field, it is one of the main components of the latest Covid vaccines. Its wide use is justified by a relatively safe profile and few known side effects. However, little is known about the biophysical effects of PEG on cells such as, cell stiffness, dry mass, and total mass. Herein, exploiting a digital holographic microscope, an inertial picobalance, and a nanoindenter, these properties are characterized in rat embryonic fibroblast exposed to different molecular weights of PEG. Immediately after the first minutes of PEG exposure to the cells, a reduction in cell dry mass can be observed as well as a rapid fluctuation in total cell weight. Cell stiffness decreases significantly after 48 h, while no important morphological changes are observed. Here, it is revealed how dry mass and total mass are rapidly and finely regulated, highlighting how the maintenance of cell density is of primary importance in cellular activities.

A polyethylene glycol enhanced ligation-triggered self-priming isothermal amplification for the detection of SARS-CoV-2 D614G mutation.

We presented a polyethylene glycol (PEG) enhanced ligation-triggered self-priming isothermal amplification (PEG-LSPA) for the detection D614G mutation in S-glycoprotein of SARS-CoV-2. PEG was employed to improve the ligation efficiency of this assay by constructing a molecular crowding environment. Two hairpin probes (H1 and H2) were designed to contain 18 nt and 20 nt target binding site at their 3' end and 5' end, respectively. In presence of target sequence, it complemented with H1 and H2 to trigger ligation by ligase under molecular crowding condition to form ligated H1-H2 duplex. Then 3' terminus of the H2 would be extended by DNA polymerase under isothermal conditions to form a longer extended hairpin (EHP1). 5' terminus of EHP1 with phosphorothioate (PS) modification could form hairpin structure due to the lower Tm value. The resulting 3' end overhang would also fold back as a new primer to initiate the next round of polymerization, resulting in the formation of a longer extended hairpin (EHP2) containing two target sequence domains. In the circle of LSPA, long extended hairpin (EHPx) containing numerous target sequence domains was produced. The resulting DNA products can be monitored in real-time fluorescence signaling. Our proposed assay owns an excellent linear range from 10 fM to 10 nM with a detection limit down to 4 fM. Thus, this work provides a potential isothermal amplification method for monitoring mutations in SARS-CoV-2 variants.

Using molecular tools to compare various concentration protocols prior to detecting SARS-CoV-2 RNA in wastewater. (Special Issue: Chemistry and global challenges (part A).)

Background: Reports showed presence of SARS-CoV-2 genetic material in wastewater. Wastewater concentration methods are optimized for detection of non-enveloped viruses so need to be adopted for enveloped viruses and their genetic material. Methods: Conventional (cRT-PCR) and quantitative real time RT-PCR (qRT-PCR) were used as readouts to compare 4 water concentration methods namely, (A) filtration on negatively charged membrane followed by extracting RNA from it, (B) adsorbtion-elution method, (C) flocculation with skimmed milk and (D) polyethylene glycol precipitation, to detect SARS-CoV-2 RNA and 229E human coronavirus (229E-HCoV) as a model for spike-containing enveloped virus from fresh and wastewater. Results: On using cRT-PCR: recovery rate of SARS-CoV-2 RNA was better using method A then B for fresh water and method B then D for wastewater. 229E-HCoV recovery from fresh water was better using method C then A and methods B then D for wastewater. On using qRT-PCR, both methods A and B were better for SARS-CoV-2 RNA recovery from both fresh and wastewater. For the 229E-HCoV methods A was the most efficient for fresh water and method B for wastewater. Conclusion: Method B is recommended for SARS-CoV-2 RNA or whole 229E-HCoV recovery from wastewater.

Evaluation of association of anti-PEG antibodies with anaphylaxis after mRNA COVID-19 vaccination.

BACKGROUND: The mechanism for anaphylaxis following mRNA COVID-19 vaccination has been widely debated; understanding this serious adverse event is important for future vaccines of similar design. A mechanism proposed is type I hypersensitivity (i.e., IgE-mediated mast cell degranulation) to polyethylene glycol (PEG). Using an assay that, uniquely, had been previously assessed in patients with anaphylaxis to PEG, our objective was to compare anti-PEG IgE in serum from mRNA COVID-19 vaccine anaphylaxis case-patients and persons vaccinated without allergic reactions. Secondarily, we compared anti-PEG IgG and IgM to assess alternative mechanisms. METHODS: Selected anaphylaxis case-patients reported to U.S. Vaccine Adverse Event Reporting System December 14, 2020-March 25, 2021 were invited to provide a serum sample. mRNA COVID-19 vaccine study participants with residual serum and no allergic reaction post-vaccination ("controls") were frequency matched to cases 3:1 on vaccine and dose number, sex and 10-year age category. Anti-PEG IgE was measured using a dual cytometric bead assay (DCBA). Anti-PEG IgG and IgM were measured using two different assays: DCBA and a PEGylated-polystyrene bead assay. Laboratorians were blinded to case/control status. RESULTS: All 20 case-patients were women; 17 had anaphylaxis after dose 1, 3 after dose 2. Thirteen (65 %) were hospitalized and 7 (35 %) were intubated. Time from vaccination to serum collection was longer for case-patients vs controls (post-dose 1: median 105 vs 21 days). Among Moderna recipients, anti-PEG IgE was detected in 1 of 10 (10 %) case-patients vs 8 of 30 (27 %) controls (p = 0.40); among Pfizer-BioNTech recipients, it was detected in 0 of 10 case-patients (0 %) vs 1 of 30 (3 %) controls (p >n 0.99). Anti-PEG IgE quantitative signals followed this same pattern. Neither anti-PEG IgG nor IgM was associated with case status with both assay formats. CONCLUSION: Our results support that anti-PEG IgE is not a predominant mechanism for anaphylaxis post-mRNA COVID-19 vaccination.

Controversies around COVID-19 Vaccines and Antidepressants: Scope and Perspective in Malaysia.

BACKGROUND: Individuals with severe mental illness are prone to severe COVID-19 infection with increased morbidity and mortality. Psychiatric patients are often concerned about the potential interactions between the newly approved COVID-19 vaccines in Malaysia and psychotropic drugs like antidepressants. To date, such data are unavailable. OBJECTIVES: This review aims to clear the polemics of COVID-19 vaccine-antidepressants interaction in these 3 aspects: (1) cytokines and cytochrome P450 pathway, (2) blood-brain barrier (BBB) involvement and (3) and its interaction with polyethylene glycol (PEG), the potential allergenic culprit following COVID-19 vaccination. METHODS: A systemic scoping approach was employed to search for peer-reviewed journal articles across four healthcare and scientific databases (PubMed, MEDLINE, PsycINFO and Cumulative Index to Nursing and Allied Health Literature (CINAHL)). RESULTS: Antidepressants metabolism often involve the CYP450 enzymes. Vaccine-antidepressants interactions are probable, likely to be triggered by interactions of CYP450 enzymes and inflammatory cytokines, resulting in diminished drug metabolism and chemical detoxification. Aside, PEG, the excipient in mRNA-based COVID-19 vaccines and antidepressants, has been reported as the anaphylaxis causative allergen. However, whether it leads to a synergistic, potentiation or antagonistic effects when used in combination, remains to be elucidated. CONCLUSION: Psychotropic medications, including antidepressants, showed potentially relevant safety risk for COVID-19 patients. These vulnerable patient group must be prioritized for early access to safe and efficacious COVID-19 vaccines, as vaccination remains the most important public health intervention to tackle the ongoing COVID-19 pandemic.

A Combined Method Based on the FIPV N Monoclonal Antibody Immunofluorescence Assay and RT-nPCR Method for the Rapid Diagnosis of FIP-Suspected Ascites

Feline infectious peritonitis (FIP), which is caused by feline infectious peritonitis virus (FIPV), is a fatal and immunologically mediated infectious disease among cats. At present, due to the atypical clinical symptoms and clinicopathological changes, the clinical diagnosis of FIP is still difficult. The gold standard method for the differential diagnosis of FIP is immunohistochemistry (IHC) which is time-consuming and requires specialized personnel and equipment. Therefore, a rapid and accurate clinical diagnostic method for FIPV infection is still urgently needed. In this study, based on the etiological investigation of FIPV in parts of southern China, we attempted to explore a new rapid and highly sensitive method for clinical diagnosis. The results of the etiological investigation showed that the N gene of the FIPV BS8 strain had the highest homology with other strains. Based on this, a specific FIPV BS8 N protein monoclonal antibody was successfully prepared by expression of the recombinant proteins, immunization of mice, fusion and selection of hybridoma cell lines, and screening and purification of monoclonal antibodies. Furthermore, we carried out a time-saving combination method including indirect immunofluorescence assay (IFA) and nested reverse transcription polymerase chain reaction (RT-nPCR) to examine FIP-suspected clinical samples. These results were 100% consistent with IHC. The results revealed that the combined method could be a rapid and accurate application in the diagnosis of suspected FIPV infection within 24 hours. In conclusion, the combination of IFA and RT-nPCR was shown to be a fast and reliable method for clinical FIPV diagnosis. This study will provide insight into the exploitation of FIPV N antibodies for the clinical diagnosis of FIP-suspected ascites samples.

Material Design for Next-Generation mRNA Vaccines Using Lipid Nanoparticles

Vaccine development is among the critical issues for ceasing the COVID-19 pandemic. This review discusses the current usage of biomaterials in vaccine development and provides brief descriptions of the vaccine types and their working mechanisms. New types of vaccine platforms (next-generation vaccines and DNA- or mRNA-based vaccines) are discussed in detail. The mRNA vaccine encoding the spike protein viral antigen can be produced in a cell-free system, suggesting that mRNA vaccines are safer than "classic vaccines" using live or inactivated virus. The mRNA vaccine efficacy is typically high at approximately 95%. However, most mRNA vaccines need to be maintained at −20 or −70 degrees for storage for long periods (half a year) and their transportation because of mRNA vaccine instability in general, although mRNA vaccines with unmodified and self-amplifying RNA (ARCT-154, Arcturus), which have a lyophilized form, have recently been reported to be kept at room temperature. mRNA vaccines are typically entrapped in lipid nanoparticles composed of ionizable lipids, polyethylene glycol (PEG)-lipids, phospholipids, and cholesterol. These components and their composition affect mRNA vaccine stability and efficacy and the size of the mRNA vaccine. The development of an improved mRNA vaccine entrapped in sophisticated biomaterials, such as novel lipid nanoparticles, using new types of biopolymers or lipids is necessary for high efficacy, safe transportation and long-term storage of the next generation of mRNA vaccines under mild conditions. [ FROM AUTHOR] Copyright of Polymer Reviews is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Safety of COVID-19 vaccination among patients with history of allergic reactions.

Introduction: Vaccination is considered the most effective method of preventing diseases and their complications. Unfortunately, many people question their legitimacy and safety. At the beginning of 2021, a few months after the announcement of the SARS-CoV-2 pandemic by the World Health Organization (WHO), the first COVID-19 vaccines were granted a conditional marketing authorization. mRNA vaccines have attracted great interest due to the use of new technology and the content of polyethylene glycol (PEG 2000) in their composition, which may induce anaphylaxis. Due to vaccine tolerance concerns, some vaccination centres have refused to administer the vaccine to patients. Aim(s): Risk assessment of allergic reactions after administration of the COVID-19 vaccine. Material(s) and Method(s): 115 patients were admitted to the Department of Allergology and Clinical Immunology in Katowice, including 107 patients with a high risk of anaphylaxis after vaccination according to the referring physician and 8 patients with a history of hypersensitivity reactions after the first dose of COVID-19 vaccination. Patients were referred for diagnosis of hypersensitivity to components of the Pfizer/BioNTech COVID-19 vaccine and administration of the vaccine in a hospital setting. During hospitalization, all patients underwent skin prick and intradermal tests with the Pfizer/BioNTech COVID-19 vaccine components, with negative results. Patients were administered the Pfizer/BioNTech COVID-19 vaccine intramuscularly, followed by at least 60 minutes of observation in the Department. Result(s): No symptoms of early hypersensitivity were observed. One patient developed urticarial lesions on the skin of the neck approximately 4-5 hours after vaccination. Conclusion(s): The risk of anaphylaxis after COVID-19 vaccine administration is low, and only a small group of patients with an allergic history require a specialised diagnostics. Physicians authorised to administer the vaccine should be acquainted with the latest recommendations, assess the risk of anaphylaxis and avoid unnecessary delays in administering a vaccine that can protect against severe morbidity and death.Copyright © 2023, Termedia Publishing House Ltd.. All rights reserved.

[Allergy to Pfizer-BioNTech® vaccine demonstrated by skin testing]. / Alergia a la vacuna Pfizer-BioNTech® demostrada mediante pruebas cutáneas.

BACKGROUND: The Pfizer-BioNTech® BNT162b2 vaccine, provides 95% effectiveness from the second dose onwards. The reported rate of anaphylaxis to COVID-19 vaccines is 4.7 cases/million doses administered. CASE REPORT: 30-year-old female, health professional, history of allergic rhinitis, asthma, reaction to eye cosmetics and adhesive tape: erythema, edema, and local pruritus. Immediately after application of the first dose of Pfizer-BioNTech vaccine, she presented grade III anaphylaxis. The patient was stratified, phenotyped and skin tests with PEG 3350 were positive. A recommendation was issued not to reapply vaccine containing polyethylene glycol and alternatives were offered. CONCLUSIONS: An adequate risk stratification should be performed before applying mRNA-based COVID-19 vaccines for the first time in at-risk groups. In case of anaphylaxis at the first dose, phenotyping and further study with PEG skin tests should be performed and vaccination alternatives should be offered.

INTRODUCCIÓN: La vacuna Pfizer-BioNTech® BNT162b2 proporciona efectividad del 95% a partir de la segunda dosis. La tasa de anafilaxia reportada de vacunas para COVID-19 es de 4.7 casos por millón de dosis administradas. REPORTE DEL CASO: Paciente femenina de 30 años, profesional de la salud, con antecedentes de rinitis alérgica, asma, reacción a productos cosméticos en los párpados y al pegamento de la cinta adhesiva (eritema, edema y prurito local). Posterior a la aplicación de la primera dosis de la vacuna Pfizer-BioNTechÒ tuvo un evento de anafilaxia grado III. Se estratificó, fenotipificó y efectuaron pruebas cutáneas con PEG-3350, que resultaron positivas. Se sugirió no aplicar la aplicar vacuna de refuerzo que contuviera polietilenglicol y se ofrecieron alternativas de tratamiento. CONCLUSIONES: Es importante efectuar la adecuada estratificación de riesgo antes de aplicar las vacunas para COVID-19 basadas en ARNm por primera vez. En caso de anafilaxia es necesario fenotipificar y ampliar el estudio con pruebas cutáneas con PEG, además de otorgar alternativas de vacunación.

SARS-CoV-2 and allergy - what have we learned after two and a half years?

BACKGROUND: Coronavirus disease-2019 (COVID-19) has significantly hampered the regular workflow for allergists and allergy departments. MATERIALS AND METHODS: The purpose of this review is to highlight our own experiences on SARS-CoV-2 and allergy as well as to discuss findings from the literature. RESULTS: Vaccination against SARS-CoV-2 is needed for protection against severe infection. Skin reactions may arise with SARS-CoV-2 infections. Short-term general immune reactions and skin reactions are also possible upon SARS-CoV-2 vaccination; however, they recur in only a proportion of patients during follow-up vaccinations. Initial reports of anaphylaxis after vaccination fueled public fear. On the other hand, more recent epidemiologic data do not show a substantially increased anaphylaxis risk compared with other vaccines. Fear-related reactions may be essential for many "anaphylaxis" reports. In Germany, the flow chart developed by Paul-Ehrlich-Institut (PEI) and Robert-Koch-Institut (RKI) together with the allergological societies helps to care for patients with suspected "allergy history" safely and effectively. Through this, patients with increased risk of anaphylaxis to SARS-CoV-2 vaccines and their ingredients (e.g., polyethylene glycol (PEG), polysorbate 80) are identified. However, since only small amounts of these excipients are contained in mRNA vaccines, even some PEG-allergic patients can tolerate the vaccination. In Germany, an allergy test-guided procedure is recommended for high-risk patients, including an allergy history, prick tests, intradermal and basophil activation tests, and, if necessary, provocation tests. This also appears effective for anxiety reduction in patients with vaccination skepticism. To date, all of our patients have been able to be vaccinated with SARS-CoV-2 vaccines without the occurrence of significant reactions. CONCLUSION: Many initial concerns about unexpected side effects of SARS-CoV-2 vaccination have not been confirmed. The flowchart and, in the case of suspicion of hypersensitivity, an allergy test-guided risk assessment helps to reduce patients' fear of vaccination and enables safe vaccination.

Intradermal Testing With COVID-19 mRNA Vaccines Predicts Tolerance.

Background: The newly developed mRNA-based COVID-19 vaccines can provoke anaphylaxis, possibly induced by polyethylene glycol (PEG) contained in the vaccine. The management of persons with a history of PEG allergy or with a suspected allergic reaction after the first dose remains to be defined. Methods: In this real-life study, we defined two cohorts of individuals: one pre-vaccination including 187 individuals with high-risk profiles for developing anaphylaxis and a second post-vaccination including 87 individuals with suspected allergic reactions after the COVID-19 mRNA vaccine. Upon negative skin test with an mRNA vaccine, a two-step (10-90%) vaccination protocol was performed. Positive skin tests were confirmed with the basophil activation test (BAT). Results: Among 604,267 doses of vaccine, 87 suspected allergic reactions (5 after the booster) were reported to our division for further investigations: 18/87 (21%) were consistent with anaphylaxis, 78/87 (90%) were female, and 47/87 (54%) received the BNT162b2 mRNA vaccine. Vaccine skin tests were negative in 96% and 76% of the pre- and post-vaccination cohorts, respectively. A two-step vaccination was tolerated in 232/236 (98%) of individuals with negative tests. Four individuals experienced isolated asthmatic reactions during the two-step challenge. Vaccine-positive skin tests were consistently confirmed by BAT; CD63 and CD203c expression was selectively inhibited with ibrutinib, suggesting an IgE-dependent mechanism. Conclusion: Sensitization to SARS-CoV-2 mRNA vaccines can be detected with intradermal testing. Significantly more individuals were sensitized to mRNA vaccines in the post-vaccination cohort. A two-step 10-90%-vaccination protocol can be safely administered upon negative skin testing.

The microbial-killing Ag nanoparticles in food supply chain: How it was applied and what a consumer should know?

Moving to 133 years of the synthesis of citrate-stabilized silver nanoparticles (AgNPs) by M. C. Lea (published in Am. J. Sci, 1889), a myriad of scholarly works and patents were published globally demonstrating the applicability of this microbial-killing nanoparticles in various industries. One of the favorite applications is on the food supply chain whereby AgNPs serve to improve food safety and quality. In this paper, the adaptation of AgNPs in each phase of a typical food supply chain is disclosed, doubts associated with the potential risks brought by this technology, and what a consumer shall be aware of are highlighted.

Skin Testing and Basophil Activation Testing Is Useful for Assessing Immediate Reactions to Polyethylene Glycol-Containing Vaccines.

BACKGROUND: The mechanism of immediate reactions to drugs or vaccines containing polyethylene glycol (PEG) and PEG derivatives is not fully elucidated. It is considered in many instances to be IgE-mediated. Diagnosis and management of PEG allergy is topical, as BNT162b and mRNA-1273 contain PEG (2[PEG-2000]-N), and ChAdOx1-S and NVX-CoV2373 contain polysorbate 80. mRNA vaccines contain PEG 2000, which encapsulates the mRNA to impair its degradation. This PEG MW is specific to mRNA vaccines and is not used in other drugs and vaccines. PEG 2000 allergy is not well studied, as higher PEG molecular weights are implicated in most of the PEG allergy published in the literature. METHODS: We performed a literature review on PEG allergy and sought to evaluate the safety and effectiveness of our protocol for assessment of PEG 2000 and polysorbate 80 reactions in an outpatient clinic setting. All patients referred to our drug allergy service between 1 July 2021 and 31 December 2021 with suspected immediate allergy to PEG or its derivatives were eligible for the study. Skin testing (ST) and basophil activation testing (BAT) were performed for all patients to multiple PEG molecular weights (MWs). RESULTS: We reviewed twenty patients during the study period. Five patients were allergic. Fifteen patients had a masquerade of allergy and were enrolled as control patients. PEG 2000, polysorbate 80, BNT162b, and ChAdOx1-S had excellent performance characteristics on skin testing. BAT showed high specificity for all vaccines and PEG MWs. DISCUSSION: In our small study, we found ST and BAT to add useful information, particularly for PEG 2000 allergy. Further study of our protocol in larger patient cohorts will provide more information on its performance characteristics and usefulness.

The conundrum of COVID-19 mRNA vaccine-induced anaphylaxis.

Novel messenger RNA (mRNA) vaccines have proven to be effective tools against coronavirus disease 2019, and they have changed the course of the pandemic. However, early reports of mRNA vaccine-induced anaphylaxis resulted in public alarm, contributing toward vaccine hesitancy. Although initial reports were concerning for an unusually high rate of anaphylaxis to the mRNA vaccines, the true incidence is likely comparable with other vaccines. These reactions occurred predominantly in young to middle-aged females, and many had a history of allergies. Although initially thought to be triggered by polyethylene glycol (PEG), lack of reproducibility of these reactions with subsequent dosing and absent PEG sensitization point away from an IgE-mediated PEG allergy in most. PEG skin testing has poor posttest probability and should be reserved for evaluating non-vaccine-related PEG allergy without influencing decisions for subsequent mRNA vaccination. Immunization stress-related response can closely mimic vaccine-induced anaphylaxis and warrants consideration as a potential etiology. Current evidence suggests that many individuals who developed anaphylaxis to the first dose of an mRNA vaccine can likely receive a subsequent dose after careful evaluation. The need to understand these reactions mechanistically remains critical because the mRNA platform is rapidly finding its way into other vaccinations and therapeutics.

Development of thermosensitive hydrogel of Amphotericin-B and Lactoferrin combination-loaded PLGA-PEG-PEI nanoparticles for potential eradication of ocular fungal infections: In-vitro, ex-vivo and in-vivo studies.

The most prevalent conditions among ocular surgery and COVID-19 patients are fungal eye infections, which may cause inflammation and dry eye, and may cause ocular morbidity. Amphotericin-B eye drops are commonly used in the treatment of ocular fungal infections. Lactoferrin is an iron-binding glycoprotein with broad-spectrum antimicrobial activity and is used for the treatment of dry eye, conjunctivitis, and ocular inflammation. However, poor aqueous stability and excessive nasolacrimal duct draining impede these agens' efficiency. The aim of this study was to examine the effect of Amphotericin-B, as an antifungal against Candida albicans, Fusarium, and Aspergillus flavus, and Lactoferrin, as an anti-inflammatory and anti-dry eye, when co-loaded in triblock polymers PLGA-PEG-PEI nanoparticles embedded in P188-P407 ophthalmic thermosensitive gel. The nanoparticles were prepared by a double emulsion solvent evaporation method. The optimized formula showed particle size (177.0 ± 0.3 nm), poly-dispersity index (0.011 ± 0.01), zeta-potential (31.9 ± 0.3 mV), and entrapment% (90.9 ± 0.5) with improved ex-vivo pharmacokinetic parameters and ex-vivo trans-corneal penetrability, compared with drug solution. Confocal laser scanning revealed valuable penetration of fluoro-labeled nanoparticles. Irritation tests (Draize Test), Atomic force microscopy, cell culture and animal tests including histopathological analysis revealed superiority of the nanoparticles in reducing signs of inflammation and eradication of fungal infection in rabbits, without causing any damage to rabbit eyeballs. The nanoparticles exhibited favorable pharmacodynamic features with sustained release profile, and is neither cytotoxic nor irritating in-vitro or in-vivo. The developed formulation might provide a new and safe nanotechnology for treating eye problems, like inflammation and fungal infections.