Allergy to COVID-19 vaccines: A current update

Safety of COVID-19 Vaccines among People with History of Allergy: A European Active Surveillance Study

Background: Conventional vaccines rarely cause severe allergic reactions. However, the rapid development and approval of COVID-19 vaccines left limited initial data on their adverse reactions, particularly in individuals with a history of allergy. The aim of this study was to assess and compare the safety profile of different doses and brands of COVID-19 vaccines in subjects with a history of allergy vs. those without a history of allergy. Methods: From February 2021 to February 2023, a web-based prospective study gathered vaccinee-reported outcomes using electronic questionnaires across eleven European countries. Baseline and up to six follow-up questionnaires captured data on vaccinee demographics, as well as both solicited and unsolicited adverse reactions. Results: Overall, 3476 vaccinees with a history of allergy were matched with 13,872 vaccinees from the general population at the first vaccination cycle and were included in the analysis. A total of 825 vaccinees with a history of allergy who had received a booster dose, matched to 3297 vaccinees from the general population, were included in the analysis. Higher rates of ADRs occurred after the first vaccination cycle compared to after the booster dose (64-91% vs. 56-79%). However, most reported ADRs were solicited and not serious, and no case of anaphylaxis was reported. Women and vaccinees with a history of allergy reported ADRs more frequently than men and the matched controls, respectively. Compared to other COVID-19 vaccines, a higher proportion of vaccinees experiencing at least one ADR following their first vaccination cycle was observed with Comirnaty and Vaxzevria. Statistically significant differences were observed among the study cohorts for median TTO after the second dose, and for median TTR following the first vaccination cycle and booster dose (p < 0.001). Conclusions: Typically, any drug or vaccine use carries a risk of severe allergic reactions, yet the benefits of vaccination generally outweigh these potential risks, as shown with the COVID-19 vaccines.

COVID-19 vaccines: anaphylaxis and anxiety : A case study from an allergy unit

BACKGROUND

Vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) was one crucial element to overcome the coronavirus disease 2019 (COVID-19) pandemic. Even though anaphylaxis to vaccines is rare, 47 patients came to the Allergy Unit at the University Hospital Graz, Austria, reporting immediate anaphylactoid symptoms after administration of COVID-19 vaccines. In addition, 29 patients with known drug-induced anaphylaxis wanted to be tested for a possible sensitization against COVID-19 vaccines or excipients, such as polyethylene glycol (PEG) or polysorbate 80 (PS80) before the first COVID-19 vaccination. Skin prick tests and intradermal tests were performed in all 76 patients, mostly using PEG 2000, and/or PS80. Skin prick tests with COVID-19 vaccines were performed depending on availability.

OBJECTIVE

Our aim was to characterize this patient cohort in terms of patients' anaphylactoid responses, their willingness to future vaccinations against SARS-Cov‑2, and reasons for their decision.

METHODS

We developed a questionnaire and analyzed 34 completed copies.

RESULTS

Of the 47 patients with anaphylactoid reactions to COVID-19 vaccination, most were female (40 female/7 male). The skin tests, even when performed with the respective COVID-19 vaccine, were negative in all but one patient. Most patients who experienced anaphylactoid reactions after a COVID-19 vaccination, did not want another COVID-19 vaccination at the time of answering the questionnaire because of anxiety for another anaphylactoid response at the next shot. Premedication with antihistamines significantly lowered (n = 74 vaccinations) the severity of anaphylactoid responses after COVID-19 vaccinations.

CONCLUSION

Anxiety about another anaphylactoid episode hinders patients to be vaccinated against SARS-CoV‑2 again. Premedication with antihistamines and collaboration of allergologists with psychologists might lower the risk of an anaphylactic/anaphylactoid response as well anxiety in drug-induced anaphylactic patients.

Extended Intraocular Drug-Delivery Platforms for the Treatment of Retinal and Choroidal Diseases

Purpose: To review sustained-release intraocular platforms used to treat diseases of the retina and choroid. Methods: A literature review of the current applications of biomaterials for sustained-release therapy in retinal and choroidal diseases was performed. Results: Retinal and choroidal diseases, such as neovascular age-related macular degeneration (nAMD), diabetic retinopathy (DR), diabetic macular edema (DME), and uveitis, are commonly treated using intravitreal (IVT) therapies that require frequent IVT injections. Multiple sustained-release options for IVT therapy have been approved by the US Food and Drug Administration for the treatment of inflammatory eye diseases, including noninfectious uveitis, infectious diseases, and exudative retinal diseases (eg, retinal venous occlusive disease and DME) using drugs such as fluocinolone acetonide, ganciclovir, and dexamethasone. The platforms for these drugs are biodegradable or nonbiodegradable. They use biomaterials such as polymers and hydrogels and are typically implanted surgically or injected into the vitreous, where they release the drug gradually over months or years. Building on these technologies, novel platforms are being studied that are intended to treat conditions including nAMD, DR, DME, and uveitis. These platforms are being tested for their safety, efficacy, and ability to reduce the injection and visit burden. Conclusions: Multiple sustained-release ocular drug-delivery platforms are currently commercially available, and many new sustained-release IVT platforms are being investigated. The hope is that meaningfully reducing the injection burden by extending intervals between treatments while maintaining optimal efficacy will improve long-term outcomes.

Neurological manifestations of immune origin after COVID-19 vaccination: retrospective case study

Objectives: To know the frequency and characteristics of neurological manifestations of probable immune origin occurring after exposure to COVID-19 vaccination. In addition, to pre-study the usefulness of the Spanish pharmacovigilance system and lymphocyte transformation test in establishing causality. Methods: Retrospective case study, including patients admitted to the Neurology department from January 2021 to May 2022 with a probable neuroimmune disorder. Demographic, clinical and COVID-19 vaccination antecedent data were collected from medical records. Results: From a total of 108 patients, 30 were excluded due to a different etiological diagnosis after follow-up. Thirty-six patients (46.2%) had received the COVID-19 vaccine in the previous 3 months (21.8% during the previous month). BioNTech-Pfizer vaccine was the most frequent in this group (63.9%). 69/108 were female and mean age 51.2 years (SD 22.59), with no significant difference with not recently-vaccinated (U-Mann Whitney, p = 0.256). The neurological syndromes found were (vaccinated/total): polyradiculoneuropathy (8/16), encephalitis (5/11), multiple sclerosis relapse (5/16), optic neuritis (1/4), myelitis (3/6), cranial neuropathy (6/10), aseptic meningitis (1/3) and others (7/11). Acute immunosuppressive treatment was administered in 61.1% of cases and 47.2% presented complete clinical improvement, without significant differences with non-vaccinated patients (chi-square, p = 0.570). Eleven vaccinated patients were studied in the pharmacovigilance office for possible adverse drug reaction. Causality according to the Spanish pharmacovigilance system (SPVS) algorithm was "Related" to COVID-19 vaccine (score ≥ 4) in 11 cases with positive in vitro study (lymphocyte transformation test) to polyethylene glycol-2000 and polysorbate-80 in 4 cases. Conclusion: Neuroimmune disorders appearing after administration of COVID-19 vaccine do not seem to present important differentiating clinical and/or evolutive features. Delayed hypersensitivity to vaccine excipients could be one of the pathophysiological mechanisms, and lymphocyte transformation test is a useful tool to identify it.

Engineering LNPs with polysarcosine lipids for mRNA delivery

Since the approval of the lipid nanoparticles (LNP)-mRNA vaccines against the SARS-CoV-2 virus, there has been an increased interest in the delivery of mRNA through LNPs. However, current LNP formulations contain PEG lipids, which can stimulate the generation of anti-PEG antibodies. The presence of these antibodies can potentially cause adverse reactions and reduce therapeutic efficacy after administration. Given the widespread deployment of the COVID-19 vaccines, the increased exposure to PEG may necessitate the evaluation of alternative LNP formulations without PEG components. In this study, we investigated a series of polysarcosine (pSar) lipids as alternatives to the PEG lipids to determine whether pSar lipids could still provide the functionality of the PEG lipids in the ALC-0315 and SM-102 LNP systems. We found that complete replacement of the PEG lipid with a pSar lipid can increase or maintain mRNA delivery efficiency and exhibit similar safety profiles in vivo.

Coronavirus Disease 2019 mRNA Vaccination Appears Safe in Pediatric Patients With Hypersensitivity to Polyethylene Glycolated Escherichia coli L-asparaginase

Polyethylene glycol-asparaginase (PEGAsp) is an established component of acute leukemia therapy. Hypersensitivity reactions to PEGAsp occur in 10% to 15% of patients, with polyethylene glycol suggested as the antigenic culprit. As coronavirus disease 2019 (COVID-19) mRNA vaccines contain polyethylene glycol, the safety of administration of these vaccines to patients with prior PEGAsp hypersensitivity has been questioned. Between December 21, 2020 and March 3, 2022, 66 patients with acute leukemia and PEGAsp allergy received COVID-19 vaccination. No patients (0/66 0%, 95% CI: 0%-5.4%) experienced an allergic reaction to the vaccine. COVID-19 mRNA vaccination appears to be safe in pediatric and young adult patients with acute lymphoblastic leukemia with PEGAsp allergy.

Nano-PROTACs: state of the art and perspectives

PROteolysis TArgeting Chimeras (PROTACs), as a recently identified technique in the field of new drug development, provide new concepts for disease treatment and are expected to revolutionize drug discovery. With high specificity and flexibility, PROTACs serve as an innovative research tool to target and degrade disease-relevant proteins that are not currently pharmaceutically vulnerable to eliminating their functions by hijacking the ubiquitin-proteasome system. To date, PROTACs still face the challenges of low solubility, poor permeability, off-target effects, and metabolic instability. The combination of nanotechnology and PROTACs has been explored to enhance the in vivo performance of PROTACs regarding overcoming these challenging hurdles. In this review, we summarize the latest advancements in the building-block design of PROTAC prodrug nanoparticles and provide an overview of existing/potential delivery systems and loading approaches for PROTAC drugs. Furthermore, we discuss the current status and prospects of the split-and-mix approach for PROTAC drug optimization. Additionally, the advantages and translational potentials of carrier-free nano-PROTACs and their combinational therapeutic effects are highlighted. This review aims to foster a deeper understanding of this rapidly evolving field and facilitate the progress of nano-PROTACs that will continue to push the boundaries of achieving selectivity and controlled release of PROTAC drugs.

[Experiencia en la vacunación frente a la COVID-19 en personas con antecedentes de alergia.]

OBJECTIVE

A common consultation since the beginning of the vaccination campaign against COVID-19 was related to people with a history of allergy to drugs or other vaccines. The objective of the study was to describe what happened after the administration of the vaccine against COVID-19 in people with a history of moderate and severe allergy, vaccinated against COVID-19 in a Primary Care Emergency Center (PCEC).

METHODS

Observational descriptive study with sixty-four people with a history of moderate and severe allergy was carried out, vaccinated in PCEP, between May and October 2021, in the Barcelonés Nord and Maresme (Barcelona province), after assessment by primary care pharmacologists and pharmacists. The percentage of people with adverse events that occurred after vaccination during their stay in the PCEP, the types detected and severity were calculated. Subsequently, a telephone survey was conducted to determine patient satisfaction. A descriptive analysis (calculation of proportions) was performed.

RESULTS

The mean age of 49.7 years (from twelve to ninety-four years) and 90.6% were women. 87.5% of the administered vaccines were Comirnaty®. Adverse events occurring after vaccination were detected in fifteen patients (23.4%), of whom four (6.25%) were manifestations of hypersensitivity, all classified as mild. The reasons for vaccination were a history of allergy to NSAIDs (45.3%), antibiotics (32.8%), analgesics (17.2%), vaccines (28.1%), other substances (40.6%) and anaphylaxis (26.6%). The degree of general satisfaction was 9.11 (out of 10).

CONCLUSIONS

The percentage of patients with a history of anaphylaxis and allergic drug reactions who present hypersensitivity reactions to COVID-19 vaccines is 6.25% and all are mild.

Dynamic Trends and Underlying Factors of COVID-19 Vaccine Booster Hesitancy in Adults: Cross-Sectional Observational Study

BACKGROUND

COVID-19 vaccine hesitancy reduces vaccination rates, which is detrimental to building herd immunity and halting the spread of COVID-19 and its variations. Most researches have simply identified the reasons affecting COVID-19 vaccination reluctance without delving into its dynamics, which makes forecasting future trends difficult.

OBJECTIVE

This study aimed to examine the current COVID-19 vaccine booster hesitancy rate in Chinese adults as well as the dynamics of vaccine hesitancy and its influencing factors. The results of this study will have practical implications for policy responses in mainland China, and effective COVID-19 booster vaccination in specific populations.

METHODS

The web-based survey was completed by creating questionnaires and using a stratified random sampling method to collect information from adults (≥18 years old) among 2556 households in 4 geographical regions of China. We collected sociodemographic information, health status, awareness of COVID-19 and its vaccine, self-perceptions, trust in medical staff and vaccine developers, and so on. The odds ratios and 95% CI for the statistical associations were estimated using logistic regression models.

RESULTS

Overall, 6659 participants (females: n=3540, 53.2%; males: n=3119, 46.8%) responded. In total, 533 (8%; 95% CI 7.4%-8.7%) participants presented a clear hesitancy in receiving the COVID-19 booster vaccination, while 736 (11.1%; 95% CI 10.3%-11.8%) expressed hesitancy in regular booster vaccination. A higher prevalence of vaccine hesitancy in both booster vaccination and regular booster vaccination was observed among participants with a history of allergies, experiencing chronic disease, lower levels of public health prevention measures or susceptibility or benefits or self-efficiency, higher levels of severity or barriers, and lower trust in both medical staff and vaccine developers (P<.05). The females and participants with higher education levels, higher levels of barriers, lower levels of susceptibility, and lower trust in vaccine developers preferred to have attitudinal changes from acceptance to hesitancy, while people with higher education levels, lower self-report health conditions, experiencing chronic disease, history of allergies, and lower trust in medical staff and developers were all positively associated with constant COVID-19 booster hesitancy.

CONCLUSIONS

The prevalence of COVID-19 vaccine booster hesitancy is not high in mainland China. However, there is a slight increment in hesitancy on regular booster vaccination. Conducting targeted information guidance for people with higher education levels and chronic diseases, as well as improving accessibility to booster vaccination and increasing trust in medical staff and vaccine producers may be highly effective in reducing vaccine hesitancy.

Immune-Mediated Organ-Specific Reactions to COVID-19 Vaccines: A Retrospective Descriptive Study

Severe acute respiratory syndrome coronavirus 2 caused the global COVID-19 pandemic and public health crisis, and it led to the rapid development of COVID-19 vaccines, which can cause rare and typically mild hypersensitivity reactions (HRs). Delayed HRs to COVID-19 vaccines have been reported, and the excipients polyethylene glycol (PEG)2000 and polysorbate 80 (P80) are the suspected culprits. Skin patch tests do not help in diagnosing delayed reactions. We aimed to perform lymphocyte transformation tests (LTT) with PEG2000 and P80 in 23 patients with suspected delayed HRs. Neurological reactions (n = 10) and myopericarditis reactions (n = 6) were the most frequent complications. Seventy-eight percent (18/23) of the study patients were admitted to a hospital ward, and the median time to discharge was 5.5 (IQR, 3-8) days. Some 73.9% of the patients returned to baseline condition after 25 (IQR, 3-80) days. LTT was positive in 8/23 patients (5/10 neurological reactions, 2/4 hepatitis reactions and 1/2 rheumatologic reactions). All myopericarditis cases had a negative LTT. These preliminary results indicate that LTT with PEGs and polysorbates is a useful tool for identifying excipients as causal agents in HRs to COVID-19 vaccines and can play an important role in risk stratification in patients with HRs.

[Reasons for allergology consultations prior to COVID-19 vaccination and their outcomes : Two-year experience of an allergy center in North Rhine-Westphalia]

BACKGROUND

To counteract the coronavirus disease 2019 (COVID-19) pandemic, several severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) vaccines have been licensed since December 2020. Shortly after the start of the vaccination campaigns, occasional allergic reactions related to vaccines were described, thus, leading to concerns in many patients with a history of allergies. The aim of this work was to evaluate which anamnestic events represented a reason for an allergology work-up before COVID-19 vaccination. Furthermore, the results of the allergology diagnostics are described.

METHODS

We performed a retrospective data analysis of all patients who presented at the Center for Dermatology, Allergology and Dermatosurgery of the Helios University Hospital Wuppertal during the years 2021 and 2022 for allergology work-up prior to COVID-19 vaccination. Demographic data, allergological history, reason for the consultation in the clinic and results of allergology diagnostic tests including reactions after vaccination were included.

RESULTS

A total of 93 patients presented for allergology work-up with COVID-19 vaccines. In about half of the cases, the reasons for the presentation to the clinic were doubts and concerns about allergic reactions and side effects. In all, 26.9% (25/93) of the presented patients had not previously received a COVID-19 vaccine yet and 23.7% (22/93) of patients developed non-allergic reactions after prior COVID-19 vaccine (e.g., headache, chills, fever, malaise). Of the patients, 46.2% (43/93) were successfully vaccinated in the clinic due to a complex allergological history, while the remaining 53.8% (50/93) were subjected to outpatient vaccination in the vaccination practice. Only one patient with known chronic spontaneous urticaria developed a mild angioedema of the lips a few hours after vaccination; however, we do not consider this episode an allergic reaction to the vaccine due to the time delay.

CONCLUSION

Allergic reactions after COVID-19 vaccines are rare, but many patients with a positive medical history of allergies are concerned about allergic reactions after COVID-19 vaccination. Thus, public work by practicing allergologists is important during vaccination campaigns to meet the concerns and fears of the population, especially of patients with allergies in their medical history.

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.

Hypereosinophilic Syndrome Following the BNT162b2 (BioNTech/Pfizer) Vaccine Successfully Treated with Mepolizumab: A Case Report and Review of the Literature

Although an increasing number of real-life data confirm large-scale clinical trial findings on the efficacy and safety of SARS-CoV-2 vaccines, rare but severe adverse reactions have begun to emerge. Here, we report a full-blown hypereosinophilic syndrome (HES) following a BNT162b2 (BioNTech/Pfizer) vaccine. A 48-year-old man developed, 5 days after the first shot of the SARS-CoV-2 vaccine, erythematous and painful nodular lesions in the lower and upper limbs accompanied by widespread itching, acrocyanosis with gangrenous lesions at the tips of the first and fourth fingers of the right hand, as well as paresthesia in the right hand and foot. Investigations revealed isolated eosinophilia, occlusion of the right ulnar artery, and electromyography alteration compatible with multifocal sensory neuropathy, as well as minimal accentuation of the interstitial texture with some ground glass appearance. Despite treatment with prednisone in combination with warfarin, he developed thrombosis of the left ulnar artery. Therefore, therapy with an IL-5 inhibitor and acetylsalicylic was successfully added. Given the time interval between the onset of clinical manifestations and the vaccine shot, we believe that the mRNA vaccine triggered the eosinophilic response. This case evidences a possible link between HES and the SARS-CoV-2 vaccination. Mepolizumab, an IL-5 inhibitor, might be considered in steroid refractory cases.

Cutaneous manifestations of COVID-19 and COVID-19 vaccination

In December 2019, a new infectious pathogen named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China. Transmitted through respiratory droplets, SARS-CoV-2 is the causative pathogen of coronavirus disease 2019 (COVID-19). Although this new COVID-19 infection is known to cause primarily interstitial pneumonia and respiratory failure, it is often associated with cutaneous manifestations as well. These manifestations with COVID-19 can be classified into seven categories: (i) chilblain-like skin eruption (e.g., COVID toes), (ii) urticaria-like skin eruption, (iii) maculopapular lesions, (iv) vesicular eruptions, (v) purpura, (vi) livedo reticularis and necrotic lesions, (vii) urticarial vasculitis, and others such as alopecia and herpes zoster. The pathogenesis of skin eruptions can be broadly divided into vasculitic and inflammatory skin eruptions. Various cutaneous adverse reactions have also been observed after COVID-19 mRNA vaccination. The major cutaneous adverse reactions are type I hypersensitivity (urticaria and anaphylaxis) and type IV hypersensitivity (COVID arm and erythema multiform). Autoimmune-mediated reactions including bullous pemphigus, vasculitis, vitiligo, and alopecia areata have also been reported. Several cases with chilblain-like lesions and herpes zoster after COVID-19 mRNA vaccination have been published. Various skin diseases associated with COVID-19 and COVID-19 vaccination have been reported, and the mechanism has been partly elucidated. In the process, for example, some papers have reported that it is not related to COVID-19 infection, although it was initially called COVID-toe and considered a COVID-19-associated cutaneous eruption. In fact, some COVID-19-associated skin reactions are indistinguishable from drug eruptions. In the future, the mechanisms of COVID-19- or COVID-19 vaccine-associated skin reactions need to be elucidated and verification of causal relationships is required.

A PEG-lipid-free COVID-19 mRNA vaccine triggers robust immune responses in mice

COVID-19 mRNA vaccines represent a completely new category of vaccines and play a crucial role in controlling the COVID-19 pandemic. In this study, we have developed a PEG-lipid-free two-component mRNA vaccine (PFTCmvac) by formulating mRNA encoding the receptor binding domain (RBD) of SARS-CoV-2 into lipid-like nanoassemblies. Without using polyethylene glycol (PEG)-lipids, the self-assembled PFTCmvac forms thermostable nanoassemblies and exhibits a dose-dependent cellular uptake and membrane disruption, eventually leading to high-level protein expression in both mammalian cells and mice. Vaccination with PFTCmvac elicits strong humoral and cellular responses in mice, without evidence of significant adverse reactions. In addition, the vaccine platform does not trigger complement activation in human serum, even at a high serum concentration. Collectively, the PEG-lipid-free two-component nanoassemblies provide an alternative delivery technology for COVID-19 mRNA vaccines and opportunities for the rapid production of new mRNA vaccines against emerging infectious diseases.

COVID-19 vaccines adverse events: potential molecular mechanisms

COVID-19 is an infectious disease caused by a single-stranded RNA (ssRNA) virus, known as SARS-CoV-2. The disease, since its first outbreak in Wuhan, China, in December 2019, has led to a global pandemic. The pharmaceutical industry has developed several vaccines, of different vector technologies, against the virus. Of note, among these vaccines, seven have been fully approved by WHO. However, despite the benefits of COVID-19 vaccination, some rare adverse effects have been reported and have been associated with the use of the vaccines developed against SARS-CoV-2, especially those based on mRNA and non-replicating viral vector technology. Rare adverse events reported include allergic and anaphylactic reactions, thrombosis and thrombocytopenia, myocarditis, Bell's palsy, transient myelitis, Guillen-Barre syndrome, recurrences of herpes-zoster, autoimmunity flares, epilepsy, and tachycardia. In this review, we discuss the potential molecular mechanisms leading to these rare adverse events of interest and we also attempt an association with the various vaccine components and platforms. A better understanding of the underlying mechanisms, according to which the vaccines cause side effects, in conjunction with the identification of the vaccine components and/or platforms that are responsible for these reactions, in terms of pharmacovigilance, could probably enable the improvement of future vaccines against COVID-19 and/or even other pathological conditions.

A novel TCNN-Bi-LSTM deep learning model for predicting sentiments of tweets about COVID-19 vaccines

Many researchers in various disciplines have focused on extracting meaningful information from social media platforms in recent years. Identification of behaviors and emotions from user posts is examined under the heading of sentiment analysis (SA) studies using the natural language processing (NLP) techniques. In this study, a novel TCNN-Bi-LSTM model using the two-stage convolutional neural network (TCNN) and bidirectional long short-term memory (Bi-LSTM) architectures was proposed. While TCNN layers enable the extraction of strong local features, the output of these layers feeds the Bi-LSTM model that remembers forward-looking information and capture long-term dependencies. In this study, first, preprocessing steps were applied to the raw dataset. Thus, strong features were extracted from the obtained quality dataset using the FastText word embedding technique that pre-trained with location-based and sub-word information features. The experimental results of the proposed method are promising compared to the baseline deep learning and machine learning models. Also, experimental results show that while the FastText data embedding technique achieves the best performance compared to other word embedding techniques in all deep learning classification models, it has not had the same outstanding success in machine learning models. This study aims to investigate the sentiments of tweets about the COVID-19 vaccines and comments on these tweets among Twitter users by using the power of Twitter data. A new dataset collected from Twitter was constructed to be used in experimental results. This study will facilitate detecting inappropriate, incomplete, and erroneous information about vaccination. The results of this study will enable society to broaden its perspective on the administered vaccines. It can also assist the government and healthcare agencies in planning and implementing the vaccination's promotion on time to achieve the herd immunity provided by the vaccination.

Therapeutic potential of compounds targeting SARS-CoV-2 helicase

The economical and societal impact of COVID-19 has made the development of vaccines and drugs to combat SARS-CoV-2 infection a priority. While the SARS-CoV-2 spike protein has been widely explored as a drug target, the SARS-CoV-2 helicase (nsp13) does not have any approved medication. The helicase shares 99.8% similarity with its SARS-CoV-1 homolog and was shown to be essential for viral replication. This review summarizes and builds on existing research on inhibitors of SARS-CoV-1 and SARS-CoV-2 helicases. Our analysis on the toxicity and specificity of these compounds, set the road going forward for the repurposing of existing drugs and the development of new SARS-CoV-2 helicase inhibitors.

Study of Excipients in Delayed Skin Reactions to mRNA Vaccines: Positive Delayed Intradermal Reactions to Polyethylene Glycol Provide New Insights for COVID-19 Arm

BACKGROUND

Skin local reactions to mRNA COVID-19 vaccines have been linked to the use of vaccine excipients. The aim of the study is to evaluate the role of skin testing excipients in delayed skin reactions due to mRNA COVID-19 vaccines.

METHODS

Skin testing among a group of healthcare workers with skin reactions due to mRNA vaccines was performed. Patch testing and intradermal testing (IDT) with polyethylene glycol (PEG)-400, PEG-2000, trometamol, and 1,2-dimyristoyl-sn-glycero-3-phosphocholine were performed. Healthcare workers without skin reactions to vaccines were used for skin testing as controls.

RESULTS

Thirty-one healthcare workers (from a total of 4315 vaccinated healthcare workers) experienced cutaneous adverse vaccine reactions. Skin testing was performed in sixteen of the healthcare workers (11 delayed large local reactions (DLLR) and 5 widespread reactions). Positive IDT for PEG-2000 1% in DLLR was seen in 10 (90.9%) patients, in comparison with one (16.6%) individual with a delayed widespread reaction. Delayed positive IDT reactions for PEG-2000 1% on day 2 were observed in three (27.3%) patients with DLLR. Patch testing of the excipients was negative. Among 10 controls, only one exhibited a transient positive IDT reaction to PEG-2000 1%.

CONCLUSIONS

Immediate and delayed reactions to IDT are frequently detected in patients with DLLR. The observation of positive delayed intradermal reactions to PEG disclosed only in patients with DLLR reinforces a possible role of PEG in the development of these reactions. Skin testing of other excipients is of little importance in clinical practice.

Positive perception of COVID-19 vaccination in HAE: No significant impact of vaccination on disease course

Background: There are some adverse effects with coronavirus disease 2019 (COVID-19) vaccines, but the impact of COVID-19 vaccination on attacks in hereditary angioedema (HAE) is not well defined. Objective: We aimed to investigate the influence of COVID-19 vaccination on the course of HAE. Method: The COVID-19 vaccination status was determined in 140 adult patients with HAE. The number and severity of attacks recorded from patients' diaries were evaluated at four different periods, comprising 1 month before the first dose, the period between the first and the second doses of COVID-19 vaccine in all the patients, the period between the second dose and the third doses in those who received three doses, and 1 month after the last vaccination dose. The disease and attack severities were assessed with the disease severity score (DSS) and 10-point visual analog scale, respectively. The patients were divided into two main groups as group 1 (those who had at least two doses of COVID-19 vaccines [n = 114]) and group 2 (those who had no vaccination [n = 26]). Only Sinovac and Biontech, which were only approved in Turkey. Results: The mean ± standard deviation DSS was significantly higher in the patients who experienced an attack after vaccination within 48 hours (6.61 ± 1.88 versus 4.14 ± 1.69; p < 0.001). Long-term prophylaxis was less common in the patients with an increased number of attacks (n = 5 (27.8%) versus n = 54 (56.3%); p = 0.027). The number of patients with less than a high school education was higher in group 2 (n = 23 [88.5%]) than in group 1 (n = 26 [3.1%]) (p < 0.001). The number of patients who had concerns about the triggering of a vaccine-induced HAE attack or about the possible vaccine adverse effects was higher in group 2 (n = 26 [100%]) than in group 1 (n = 74 [64.9%]). Conclusion: It seems that COVID-19 vaccination does not increase HAE attacks regardless of the type of the vaccines. We recommend that HAE activity should be under control before COVID-19 vaccination, and the patients should be well informed about the safety of the vaccines.

Allergy Workup in the Diagnosis of COVID-19 Vaccines-Induced Hypersensitivity Reactions and Its Impact on Vaccination

INTRODUCTION

Immediate and delayed hypersensitivity reactions (HSR) to COVID-19 vaccines are rare adverse events that need to be prevented, diagnosed, and managed in order to guarantee adherence to the vaccination campaign. The aims of our study were to stratify the risk of HSR to COVID-19 vaccines and propose alternative strategies to complete the vaccination.

METHODS

1,640 subjects were screened for vaccinal eligibility, according to national and international recommendations. Among them, we enrolled for allergy workup 152 subjects, 43 with HSR to COVID-19 vaccines and 109 at high risk of HSR to the first dose. In vivo skin tests with drugs and/or vaccines containing PEG/polysorbates were performed in all of them, using skin prick test and, when negative, intradermal tests. In a subgroup of patients resulted negative to the in vivo skin tests, the programmed dose of COVID-19 vaccine (Pfizer/BioNTech) was administered in graded doses regimen, and detection of neutralizing anti-spike antibodies was performed in these patients after 4 weeks from the vaccination, using the SPIA method.

RESULTS

Skin tests for PEG/polysorbates resulted positive in only 3% (5/152) of patients, including 2 with previous HSR to COVID-19 vaccines and 3 at high risk of HSR to the first dose. Among the 147 patients with negative skin tests, 97% (143/147) were eligible for vaccination and 87% (124/143) of them received safely the programmed COVID-19 vaccine dose. Administration of graded doses of Pfizer/BioNTech vaccine were well tolerated in 17 out of 18 patients evaluated; only 1 developed an HSR during the vaccination, less severe than the previous one, and all developed neutralizing anti-spike antibodies after 4 weeks with values comparable to those subjects who received the vaccine in unfractionated dose.

CONCLUSION

On the whole, the usefulness of the skin tests for PEG/polysorbates seems limited in the diagnosis of HSR to COVID-19 vaccines. Graded doses regimen (Pfizer/BioNTech) is a safe and effective alternative strategy to complete the vaccinal course.

Discrete Libraries of Amphiphilic Poly(ethylene glycol) Graft Copolymers: Synthesis, Assembly, and Bioactivity

Poly(ethylene glycol) (PEG) is an important and widely used polymer in biological and pharmaceutical applications for minimizing nonspecific binding while improving blood circulation for therapeutic/imaging agents. However, commercial PEG samples are polydisperse, which hampers detailed studies on chain length-dependent properties and potentially increases antibody responses in pharmaceutical applications. Here, we report a practical and scalable method to prepare libraries of discrete PEG analogues with a branched, nonlinear structure. These lipid-PEG derivatives have a monodisperse backbone with side chains containing a discrete number of ethylene glycol units (3 or 4) and unique functionalizable chain ends. Significantly, the branched, nonlinear structure is shown to allow for efficient nanoparticle assembly while reducing anti-PEG antibody recognition when compared to commercial polydisperse linear systems, such as DMG-PEG2000. By enabling the scalable synthesis of a broad library of graft copolymers, fundamental self-assembly properties can be understood and shown to directly correlate with the total number of PEG units, nature of the chain ends, and overall backbone length. These results illustrate the advantages of discrete macromolecules when compared to traditional disperse materials.

Serum polyethylene glycol-specific IgE and IgG in patients with hypersensitivity to COVID-19 mRNA vaccines

BACKGROUND

The mechanism of allergic reactions to COVID-19 mRNA vaccines has not been clarified. Polyethylene glycol (PEG) is a potential antigen in the components of vaccines. However, there is little evidence that allergy after COVID-19 mRNA vaccination is related to PEG. Furthermore, the role of polysorbate (PS) as an antigen has also not been clarified. The objective of this study was to investigate whether PEG and PS allergies are reasonable causes of allergic symptoms after vaccination by detecting PEG-specific and PS-specific antibodies.

METHODS

Fourteen patients who developed immediate allergic reactions to BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccines and nineteen healthy controls who did not present allergic symptoms were recruited. Serum PEG-specific immunoglobulin E (IgE) and immunoglobulin G (IgG) and PS-specific IgE and IgG were measured by enzyme-linked immunosorbent assay. Skin tests using PEG-2000 and PS-80 were applied to five patients and three controls.

RESULTS

Serum levels of PEG-specific IgE and IgG in patients with immediate allergic reactions to the COVID-19 mRNA vaccine were higher than those in the control group. Serum levels of PS-specific IgE in patients with allergy to the vaccine were higher than those in patients of the control group. Intradermal tests using PEG verified the results for PEG-specific IgE and IgG.

CONCLUSIONS

The results suggest that PEG is one of the antigens in the allergy to COVID-19 mRNA vaccines. Cross-reactivity between PEG and PS might be crucial for allergy to the vaccines. PEG-specific IgE and IgG may be useful in diagnosing allergy to COVID-19 mRNA vaccines.

Assessment of Immediate Allergic Reactions After Immunization With the Pfizer BNT162b2 Vaccine Using Intradermal Skin Testing With the COVID-19 Vaccines

Background

Allergic reactions to the coronavirus disease 2019 (COVID-19) vaccines have raised concerns, particularly as repeated doses are required. Skin tests with the vaccines excipient were found to be of low value, whereas the utility of skin tests with the whole vaccine is yet to be determined.

Objective

To evaluate a panel of skin tests and the outcomes of subsequent doses of immunization among subjects who suffered an immediate allergic reaction to the BioNTech (BNT162b2) COVID-19 vaccine.

Methods

Between March and December 2021, patients who experienced symptoms consistent with immediate allergic reactions to the BNT162b2 vaccine and were referred to the Sheba Medical Center underwent skin testing with polyethylene glyol (PEG)-containing medicines, Pfizer-BNT162b2, and Oxford–AstraZeneca vaccine (AZD1222). Further immunization was performed accordingly and under medical observation.

Results

A total of 51 patients underwent skin testing for suspected allergy to the COVID vaccines, of which 38 of 51 (74.5%) were nonreactive, 7 of 51(13.7%) had no skin sensitization but suffered a clinical reaction during skin testing (mainly cough), and 6 of 51 (11.7%) exhibited immediate skin sensitization. Both skin sensitization and cough during testing were related to a higher use of adrenaline following immunization (P = .08 and P = .024, respectively). Further immunization with the BNT162b2 vaccine was recommended unless sensitization or severe reaction to previous immunization was evident. The latter were referred to be tested/receive the alternative AZD1222 vaccine. Ten patients underwent skin testing with AZD1222: 2 of 10 (20%) demonstrated skin sensitization to both vaccines; thus, 8 of 10 were immunized with the AZD1222, of which 2 of 8 (25%) had allergic reactions.

Conclusions

Immediate allergic reactions to COVID-19 vaccines are rare but can be severe and reoccur. Intradermal testing with the whole vaccine may discriminate sensitized subjects, detect cross-sensitization between vaccines, and enable estimation of patients at higher risk.

Autopsy findings of post-COVID-19 vaccination deaths in Tokyo Metropolis, Japan, 2021

BACKGROUND

COVID-19 vaccines have been used across Japan since 17 February 2021, and as of 17 April 2022, 1690 deaths potentially caused by vaccine-related adverse effects have been reported to the Ministry of Health, Labour and Welfare. However, the causal relationship between vaccination and death could not be fully evaluated because of a lack of sufficient information.

METHODS

Autopsy cases in which deaths occurred within seven days after COVID-19 vaccination in Tokyo Metropolis and were handled by medical examiners were selected (n = 54). Age, sex, vaccine-related information, cause of death, and possible causal relationship between vaccination and death were examined.

RESULTS

The mean age of the deceased individuals was 68.1 years, and the study sample consisted of 34 males (63.9%) and 20 females (37.0%). Thirty-seven and six individuals received Comirnaty and Spikevax, respectively (68.5% and 11.1% respectively). The manner of death included natural (n = 43), non-natural (n = 8), and undetermined (n = 3). The most frequent cause of death was ischemic heart disease (n = 16). Regarding causal relationships, 46 cases (85.2%) did not show a causal relationship to vaccination, except for myocarditis (n = 3), thrombosis-related death (n = 4), and others (n = 1).

CONCLUSION

Although many cases of deaths after COVID-19 vaccination in this study showed no definite causal relationship between the vaccination and deaths, some cases showed possible adverse events such as myocarditis. Autopsies are essential for detecting vaccine-related deaths, and the Japanese death investigation system needs to be reinforced from this viewpoint.

Rare Heterogeneous Adverse Events Associated with mRNA-Based COVID-19 Vaccines: A Systematic Review

Background: Since the successful development, approval, and administration of vaccines against SARS-CoV-2, the causative agent of COVID-19, there have been reports in the published literature, passive surveillance systems, and other pharmacovigilance platforms of a broad spectrum of adverse events following COVID-19 vaccination. A comprehensive review of the more serious adverse events associated with the Pfizer-BioNTech and Moderna mRNA vaccines is warranted, given the massive number of vaccine doses administered worldwide and the novel mechanism of action of these mRNA vaccines in the healthcare industry. Methods: A systematic review of the literature was conducted to identify relevant studies that have reported mRNA COVID-19 vaccine-related adverse events. Results: Serious and severe adverse events following mRNA COVID-19 vaccinations are rare. While a definitive causal relationship was not established in most cases, important adverse events associated with post-vaccination included rare and non-fatal myocarditis and pericarditis in younger vaccine recipients, thrombocytopenia, neurological effects such as seizures and orofacial events, skin reactions, and allergic hypersensitivities. Conclusions: As a relatively new set of vaccines already administered to billions of people, COVID-19 mRNA-based vaccines are generally safe and efficacious. Further studies on long-term adverse events and other unpredictable reactions in close proximity to mRNA vaccination are required.

Anisodamine potently inhibits SARS-CoV-2 infection in vitro and targets its main protease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provoked a pandemic of acute respiratory disease, namely coronavirus disease 2019 (COVID-19). Currently, effective drugs for this disease are urgently warranted. Anisodamine is a traditional Chinese medicine that is predicted as a potential therapeutic drug for the treatment of COVID-19. Therefore, this study aimed to investigate its antiviral activity and crucial targets in SARS-CoV-2 infection. SARS-CoV-2 and anisodamine were co-cultured in Vero E6 cells, and the antiviral activity of anisodamine was assessed by immunofluorescence assay. The antiviral activity of anisodamine was further measured by pseudovirus entry assay in HEK293/hACE2 cells. Finally, the predictions of crucial targets of anisodamine on SARS-CoV-2 were analyzed by molecular docking studies. We discovered that anisodamine suppressed SARS-CoV-2 infection in Vero E6 cells, and reduced the SARS-CoV-2 pseudovirus entry to HEK293/hACE2 cells. Furthermore, molecular docking studies indicated that anisodamine may target SARS-CoV-2 main protease (M^pro) with the docking score of −6.63 kcal/mol and formed three H-bonds with Gly143, Cys145, and Cys44 amino acid residues at the predicted active site of M^pro. This study suggests that anisodamine is a potent antiviral agent for treating COVID-19.

Reactivation of adult-onset Still’s disease after use of the COVID-19 ChAdOx1-S vaccine

A woman in her 60s with a history of adult-onset Still’s disease (AOSD) in remission for 14 years received the ChAdOx1-S vaccine as a booster to her initial vaccination schedule (two doses of CoronaVac vaccine 6 months apart). Two weeks later, she consulted for symptoms suggestive of AOSD reactivation. This was confirmed during hospitalisation, where renal and cardiac involvement were also observed. Despite using high-dose corticosteroids, troponin T and N-terminal pro hormone B-type natriuretic peptide (NT-proBNP) were persistently elevated. Tocilizumab was used, with which the patient achieved complete remission of her symptoms and normalised her laboratory tests.

New Challenges in Drug Allergy: the Resurgence of Excipients

Purpose of Review

Allergy to excipients is a cause of multidrug allergy and if it is not taken into account, it can lead to unexpected severe reactions. If an excipient allergy is suspected, an accurate examination followed by algorithms is very important for a correct diagnosis and to give patients detailed information in order to avoid future reactions.

Recent Findings

In recent times, due to allergy COVID vaccine reactions, interest in excipients as polyethylene glycol derivatives (PEGs) has increased as a possible cause of drug and vaccine hypersensivity. In addition to PEGs many other excipients as gelatin, alpha-gal, protamine, benzalkonium chloride, and benzyl alcohol have been described as a cause of allergy to drugs and vaccines. For most excipients, the dilutions used for skin testing (ST) are not standardized and proper algorithms to reach a diagnosis are not available.

Summary

The purpose of this article is to review the excipients that may produce inmediate hypersensitivity drugs and vaccine reactions and update diagnostic procedures to reach an accurate diagnosis. We highlight the in vivo and in vitro diagnostic tests used in published reports and detail the dilution used for each excipient to perform ST in order to confirm this vital pathology and to prevent new reactions.

COVID vaccination can be completed in subjects with a history of allergic reactions to the vaccines or their components - experience from a specialist clinic in South Australia

The development of vaccines against SARS-CoV2 has been a key public health response to the COVID-19 pandemic. However, since their introduction there have been reports of anaphylactic reactions in vaccinees with history of allergy. We developed an allergy testing protocol allowing vaccination with available COVID-19 vaccines in Australia. Patients referred to a state-wide COVID-19 vaccine allergy clinic between March and August 2021 with a history of allergy underwent skin prick testing and intradermal testing to both available vaccine formulations (BNT162b2, ChAdOx1-S), excipients (polyethylene glycol, polysorbate 80), excipient-containing medications, and controls. Where available, basophil activation testing was conducted. 53 patients underwent testing for possible excipient allergy (n = 19), previous non-COVID vaccine reaction (n = 13), or previous reaction to dose 1 of COVID-19 vaccine (n = 21). Patients were predominantly female (n = 43, 81%), aged 18-83 (median 54) years. 44 patients tested negative and 42 of these received at least their first dose of a COVID-19 vaccine. 9 patients tested positive to excipients or excipient-containing medication only (n = 3), or vaccines (n = 6). 5 patients were positive to just BNT162b2, 3/5 have been vaccinated with ChAdOx1-S. 1 who was skin test positive to both vaccines, but negative BAT to ChAdOx1-S was successfully vaccinated with ChAdOx1-S. Even in a high-risk population, most patients can be vaccinated with available COVID-19 vaccines. This paper reports local experiences using a combined allergy testing protocol with skin testing and BAT during the pandemic. This article is protected by copyright. All rights reserved.

Reporting of Allergic Reactions During Pfizer-BioNTech BNTT162B2 Vaccination in Israel

Background

In December 2020, the Israeli Ministry of Health launched a national vaccination campaign against SARS-CoV-2. Concomitant sporadic reports on anaphylactic responses in other countries raised safety concerns at the outset of this operation.

Objective

To characterize reports on allergic reactions to coronavirus disease 2019 vaccines.

Methods

Allergy events were reported by health care professionals throughout the country to Israeli Ministry of Health Division of Epidemiology via a Web-based computerized national vaccine registry. The study period was from December 19, 2020 to September 13, 2021, during which 14,475,979 injections were administered.

Results

Allergic reactions were reported in 463 subjects, 99.3% of whom received Pfizer-BioNTech BNTT162B2. The reporting rate was 106 per million in December 2020. From January to May 2021, a reduction was observed to 66, 18, 14, eight, and zero per million, and reporting remained low until September. Mean age of subjects was 48.9 ± 16.7 years (range, 15-96 years) with a female preponderance of 78%. Epinephrine was administered in 34 subjects. Validated immediate allergy was observed in only 37 cases (8%), suggesting 2.5 to 3.3 bona fide reactions per million. In subjects with reactions classified as severe (n = 46), plausible allergy was identified in 36% to 41% of cases. A history of allergy was associated with high false reporting of immediate reactions (83%). Allergic events after the first dose did not compromise adherence to subsequent doses.

Conclusions

Excessive reporting of allergy declined over time and did not affect adherence to vaccination. The existence of previous allergy may affect reporting profiles, but not the occurrence of vaccine allergy.

Current Evidence in SARS-CoV-2 mRNA Vaccines and Post-Vaccination Adverse Reports: Knowns and Unknowns

The novel mRNA vaccinations against COVID-19 are gaining worldwide attention for their potential efficacy, as well as for the diagnosis of some post-vaccination-reported adverse reactions. In this state-of-the-art review article, we present the current evidence regarding mainly the diagnosis of spontaneous allergic reactions, the skin occurrences, the vascular, blood, endocrine and heart events, the respiratory reports, the gastrointestinal, hepatic and kidney events, the reproductive and pregnancy issues and the muscle events, as well as the ear, eye, neurologic and psychiatric events following mRNA vaccination against COVID-19. We further present some evidence regarding the mRNA strategies, we provide important information for side effects associated with the spike protein based LNP-mRNA vaccine and its adjuvants, as well as evidence for all the possible dangerous roles of the spike protein, and we discuss our expert opinion on the knowns and the unknowns towards the topic.

Immediate Hypersensitivity Reactions Induced by COVID-19 Vaccines: Current Trends, Potential Mechanisms and Prevention Strategies

As the world deals with the COVID-19 pandemic, vaccination remains vital to successfully end this crisis. However, COVID-19-vaccine-induced immediate hypersensitivity reactions presenting with potentially life-threatening systemic anaphylactic reactions are one of the reasons for vaccine hesitancy. Recent studies have suggested that different mechanisms, including IgE-mediated and non-IgE-mediated mast cell activation, may be involved in immediate hypersensitivity. The main culprits triggering hypersensitivity reactions have been suggested to be the excipients of vaccines, including polyethylene glycol and polysorbate 80. Patients with a history of allergic reactions to drugs, foods, or other vaccines may have an increased risk of hypersensitivity reactions to COVID-19 vaccines. Various strategies have been suggested to prevent hypersensitivity reactions, including performing skin tests or in vitro tests before vaccination, administering different vaccines for the primary and following boosters, changing the fractionated doses, or pretreating the anti-IgE antibody. This review discusses the current trends, potential mechanisms, and prevention strategies for COVID-19-vaccine-induced immediate hypersensitivity reactions.

Second-dose COVID-19 vaccines are well tolerated in patients with allergic reactions to the first dose – a single center experience

COVID-19 vaccines contain additives such as Polyethylenglycol-2000 (PEG2000; mRNA vaccines) or Polysorbat 80 (vector vaccines), which have been described previously as culprits for anaphylactic events.

This retrospective study included 46 individuals, who were referred to Comprehensive Allergy Center at the Department Dermatology and Venereology, Kepler University Hospital, Linz, Austria, with suspected allergic reactions to the first COVID-19 vaccine dose with either mRNA or vector-based vaccines.

Patients underwent detailed anamnesis, clinical examination, and in most cases, skin prick testing using pure additive substances (PEG – different molecular weights, Polysorbate 80).

Out of 46, 7 patients’ reactions were classified as possibly anaphylactic and graded according to Ring & Messmer. Forty patients out of 46 were assessed with skin prick tests for potential allergens in COVID-19 vaccines. Only 1 patient showed an immediate positive prick test to PEG2000. Second-dose vaccination with mRNA or vector-based vaccines were tolerated well in all patients, including the individual with a positive skin prick test against PEG2000.

The currently available COVID-19 vaccines have an overall low allergic potential and may be administered safely in patients with suspected allergic reactions to the first dose.

Post COVID-19 vaccine deaths - Singapore's early experience

Singapore has been using mRNA vaccines developed by Pfizer-BioNTech and Moderna as part of the nation's COVID vaccination program since 30 December 2020. From 1 February 2021-30 June 2021, a total of 34 deaths that occurred within 72 h of the deceased receiving their COVID-19 vaccination were referred to the Forensic Medicine Division of the Health Sciences Authority of Singapore. Autopsies, histological sampling and ancillary investigations consisting of total tryptase level, Immunoglobulin E (IgE), and C-reactive Protein (CRP), were performed on 29 of these cases. Our study has shown no definite causative relationship between the mRNA vaccination and deaths of individuals who died within 72 h after receiving the vaccination, in particular with regards to anaphylactic reactions, myocarditis and pericarditis, and thrombotic complications. Further studies may consider increasing the incident time frame from 72 h to seven days post-vaccination or longer to include any potential delayed presentation of adverse effects.

Evaluation of the Autoimmunity and Preexisting Risky Conditions for Hypersensitivity Reactions to COVID-19 Vaccines

INTRODUCTION

The role of autoimmunity and other preexisting risky conditions in hypersensitivity reactions (HSRs) to COVID-19 vaccines seems unclear. The aim of the study was to investigate the autoimmunity and preexisting risky conditions in HSRs to COVID-19 vaccines.

METHODS

The patients aged ≥18 years with a history of HSR to CoronaVac or Pfizer-BioNTech COVID-19 vaccines within 24 h in 2 tertiary centers were assessed. The patients were divided according to the type of vaccine which they showed immediate-type (<4 h) HSR to (group A1 for CoronaVac and group B1 for Pfizer-BioNTech). Equal number of subjects who did not show HSR to two doses of either CoronaVac or Pfizer-BioNTech was recruited into the study as control groups (group A2 for CoronaVac and group B2 for Pfizer-BioNTech). The autologous serum skin test (ASST) was performed on patient and control groups. Later, the demographic, clinical, and laboratory features were compared between groups.

RESULTS

A total number of 27 patients were included in the study. Subjects with chronic spontaneous urticaria (CSU) were more frequent in group B1 than in group B2 (p:0.041). In addition to CSU, the presence of HSRs to drugs was higher in group A1 than in A2 (both p:0.007). The presence of autoimmunity and autoimmune diseases, positivity of antithyroid peroxidase antibody, and ASST were less in group A2 than in A1 (p:0.015, p:0.048, p:0.048, and p:0.037). Additionally, COVID-19 infection history was less in group A2 than in A1 (p:0.037).

DISCUSSION/CONCLUSION

Type IIb autoimmunity seems to play a role in immediate type HSRs to the CoronaVac vaccine as previously shown in autoimmune CSU and multidrug hypersensitivity.

The Variation of SARS-CoV-2 and Advanced Research on Current Vaccines

Over the past 2 years, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the coronavirus disease 2019 (COVID-19) and rapidly spread worldwide. In the process of evolution, new mutations of SARS-CoV-2 began to appear to be more adaptable to the diverse changes of various cellular environments and hosts. Generally, the emerging SARS-CoV-2 variants are characterized by high infectivity, augmented virulence, and fast transmissibility, posing a serious threat to the prevention and control of the global epidemic. At present, there is a paucity of effective measurements to cure COVID-19. It is extremely crucial to develop vaccines against SARS-CoV-2 and emerging variants to enhance individual immunity, but it is not yet known whether they are approved by the authority. Therefore, we systematically reviewed the main characteristics of the emerging various variants of SARS-CoV-2, including their distribution, mutations, transmissibility, severity, and susceptibility to immune responses, especially the Delta variant and the new emerging Omicron variant. Furthermore, we overviewed the suitable crowd, the efficacy, and adverse events (AEs) of current vaccines.

Updated consensus statements on COVID-19 Vaccine Allergy Safety in Hong Kong

Due to global concerns over coronavirus disease 2019 (COVID-19) vaccine-associated allergic reactions; the Hong Kong Institute of Allergy (HKIA) formulated an initial set of consensus statements (CS) on COVID-19 Vaccine Allergy Safety (VAS) in early 2021. Following accumulation of both local and international experience on and COVID-19 VAS, the HKIA task force reformed to update the Hong Kong consensus on COVID-19 VAS. A nominated task force of experts managing patients with drug and vaccine allergies in Hong Kong formulated the updated CS by unanimous decision. A total of 9 new statements were established. Individuals with history of food allergies and anaphylaxis unrelated to the components of COVID-19 vaccines do not require allergist review prior to vaccination. Individuals with history suspicious of an excipient allergy may now be vaccinated with a non-PEG containing vaccine without prior allergist assessment. Individuals with suspected mild allergic reactions following prior COVID-19 vaccination can proceed with the next dose. Only individuals who present with immediate-type allergic reaction with systemic symptoms or more severe nonimmediate type reactions should defer their next dose until allergist review. The remaining statements regarding adequate safety during vaccination and advocation for legislative changes regarding excipient disclosure in Hong Kong remained unchanged from the prior CS. The updated CS are updated in accordance with local and international experience thus far and serve as guidance for local frontline healthcare providers to further promote safe COVID-19 vaccine uptake in Hong Kong.

New-onset autoimmune phenomena post COVID-19 vaccination

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented setback for global economy and health. Vaccination is one of the most effective intervention to substantially reduce severe disease and death due to SARS-CoV-2 infection. Vaccination programs are being rolled out globally, but most of these vaccines have been approved without extensive studies on their side effects and efficacy. Recently, new-onset autoimmune phenomena after COVID-19 vaccination have been reported increasingly (e.g., immune thrombotic thrombocytopenia, autoimmune liver diseases, Guillain-Barré syndrome, IgA nephropathy, rheumatoid arthritis and systemic lupus erythematosus, etc.). Molecular mimicry, the production of particular autoantibodies and the role of certain vaccine adjuvants seem to be substantial contributors to autoimmune phenomena. However, whether the association between COVID-19 vaccine and autoimmune manifestations is coincidental or causal remains to be elucidated. Here, we summarize the emerging evidence about autoimmune manifestations occurring in response to certain COVID-19 vaccines. Although information pertaining to the risk of autoimmune disease as a consequence of vaccination is controversial, we merely propose our current understanding of autoimmune manifestations associated with COVID-19 vaccine. In fact, we do not aim to disavow the overwhelming benefits of mass COVID-19 vaccination in preventing COVID-19 morbidity and mortality. These reports could help guide clinical assessment and management of autoimmune manifestations after COVID-19 vaccination.

Deep Learning-Based Sentiment Analysis of COVID-19 Vaccination Responses from Twitter Data

The COVID-19 pandemic has had a devastating effect on many people, creating severe anxiety, fear, and complicated feelings or emotions. After the initiation of vaccinations against coronavirus, people's feelings have become more diverse and complex. Our aim is to understand and unravel their sentiments in this research using deep learning techniques. Social media is currently the best way to express feelings and emotions, and with the help of Twitter, one can have a better idea of what is trending and going on in people's minds. Our motivation for this research was to understand the diverse sentiments of people regarding the vaccination process. In this research, the timeline of the collected tweets was from December 21 to July21. The tweets contained information about the most common vaccines available recently from across the world. The sentiments of people regarding vaccines of all sorts were assessed using the natural language processing (NLP) tool, Valence Aware Dictionary for sEntiment Reasoner (VADER). Initializing the polarities of the obtained sentiments into three groups (positive, negative, and neutral) helped us visualize the overall scenario; our findings included 33.96% positive, 17.55% negative, and 48.49% neutral responses. In addition, we included our analysis of the timeline of the tweets in this research, as sentiments fluctuated over time. A recurrent neural network- (RNN-) oriented architecture, including long short-term memory (LSTM) and bidirectional LSTM (Bi-LSTM), was used to assess the performance of the predictive models, with LSTM achieving an accuracy of 90.59% and Bi-LSTM achieving 90.83%. Other performance metrics such as precision,, F1-score, and a confusion matrix were also used to validate our models and findings more effectively. This study improves understanding of the public's opinion on COVID-19 vaccines and supports the aim of eradicating coronavirus from the world.

Questionnaire Survey of Possible Association of Allergic Diseases with Adverse Reactions to SARS-CoV-2 Vaccination

To protect against COVID-19, SARS-CoV-2 vaccines have been widely used. Besides anaphylaxis, some less severe adverse effects may occur at higher frequencies. It remains unclear whether present or past histories of allergic diseases exert effects on local and systemic reactions. We conducted a questionnaire survey among workers in our hospital. We analyzed the adverse effects occurring after the first and second doses of the Pfizer–BioNTech vaccine in 955 subjects. The presence or absence of local injection reactions and systemic reactions (headache, fatigability, fever, muscle pain, and joint pain) was questioned. The intensities of these reactions were graded on a scale of 0–4 (except fever) or 0–2 (fever). The allergic diseases that we focused on were bronchial asthma, atopic dermatitis, food allergy, pollinosis, and hand eczema. For the systemic reactions, fatigability after the first dose tended to be more severe in the bronchial asthma than in the non-allergic group. Headache, joint pain, and fever tended to be more severe in the food allergy than in the non-allergic group after the second dose. For the local skin reactions, atopic dermatitis subjects tended to show rather less severe local skin reactions after the second dose. The results contribute to the guidelines for the care of individuals with different allergy histories, so that they may safely receive their vaccine.

COVID-19 mRNA vaccine allergy

PURPOSE OF REVIEW

A known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine is the only contraindication to coronavirus disease 2019 (COVID-19) mRNA vaccination. It is important for pediatricians to understand the likelihood of an allergic reaction to COVID-19 mRNA vaccines, including its excipients.

RECENT FINDINGS

Episodes concerning for anaphylaxis were immediately reported following early administration of COVID-19 mRNA vaccines to adults. Although allergic type symptoms were reported equally in recipients of placebos and test vaccines in phase 3 clinical trials, post-authorization prospective studies state that 0.2-2% of vaccine recipients have experienced allergic reactions. Subsequent allergy testing of affected individuals has focused largely on evaluation of allergic sensitization to a novel vaccine excipient, polyethylene glycol (PEG). PEG is a polymer incorporated in numerous pharmaceutical products because of its favorable, inert properties. The results of allergy testing in adults to date indicate that IgE mediated anaphylaxis to PEG allergy is rarely identified after COVID-19 mRNA vaccine reactions. Numerous individuals with presumed anaphylaxis have tolerated a second vaccine after evaluation and testing by an allergist, suggesting either misdiagnosis or a novel immune mechanism.

SUMMARY

Confirmed anaphylactic reactions to COVID-19 mRNA vaccines are rare, likely due to a lack of preexisting IgE against the vaccine components, including PEG.

Anaphylaxis rates associated with COVID-19 vaccines are comparable to those of other vaccines

We retrieved data on 8940 anaphylaxis cases post-COVID-19 vaccination from the US Vaccine Adverse Event Reporting System and the European EudraVigilance from week 52/2020 through week 31/2021 and compared them with those of other vaccines. Overall, 837,830,000 COVID-19 vaccine doses were delivered in the US and Europe during the study period, for which the vaccine name was known. The mean anaphylaxis rate was estimated at 10.67 cases per 10⁶ doses of COVID-19 vaccines (range: 7.99-19.39 cases per 10⁶ doses depending on the vaccine). COVID-19 vaccines ranked fifth in reported anaphylaxis rates, behind rabies, tick-borne encephalitis, measles-mumps-rubella-varicella, and human papillomavirus vaccines (70.77, 20, 19.8, and 13.65 cases per 10⁶ vaccine doses, respectively). COVID-19 vaccines are within the range of anaphylaxis rates reported across several common vaccines in these two passive reporting systems. These data should be communicated to reassure the general population about the safety profile of COVID-19 vaccines.

Acute Eosinophilic Pneumonia Associated With the Anti-COVID-19 Vaccine AZD1222

SARS-CoV-2 is an emerging virus causing the contemporary global pandemic. No cure has yet been discovered. Therefore, vaccination remains the only hope. We report the case of a 66-year-old male patient with a history of allergies. Five hours after his vaccination with the anti-COVID-19 vaccine AZD1222 (ChAdOx1 nCoV-19, AstraZeneca), he developed acute respiratory distress. The biological assessment showed hyperleukocytosis, 20% of which are eosinophils. Diagnosis of severe postvaccination acute eosinophilic pneumonia was retained given the history of allergy, lack of improvement on antibiotics, elimination of all other probable causes of eosinophilia, and improvement on corticosteroids. Such reactions of eosinophilic pneumonia have only been described twice: once following vaccination with the influenza vaccine (Vaxigrip*) and the other after vaccination with the 23-valent pneumococcal polysaccharide vaccine (Pneumovax 23*). Hypereosinophilia must be taken into consideration, feared, and prevented. Although rare and severe, post-COVID-19 vaccination acute eosinophilic pneumonia remains well manageable with corticosteroids with a good outcome. Therefore, in some poorly monitored patients with allergy or asthma, the use of another less allergenic vaccine could be considered to avoid such reactions.

Allergen Immunotherapy management during vaccinations: An international survey

Vaccination against viral and bacterial pathogens represents a challenging issue in allergic subjects, mainly concerning patients undergoing allergen immunotherapy (AIT). For this reason, an international survey has been performed involving a panel of experts who responded to a series of questions, also concerning the COVID-19 impact on allergen immunotherapy and vaccinations.

The results showed that co-administration of vaccines and AIT requires caution, mainly during the pandemic era. Moreover, the choice of AIT product should be oriented considering also the safety profile.