Augmented type 2 inflammatory response in allergic rhinitis patients experiencing systemic reactions to house dust mite subcutaneous immunotherapy.

BACKGROUND: Subcutaneous immunotherapy (SCIT) can induce systemic reactions (SRs) in certain patients, but the underlying mechanisms remain to be fully elucidated. METHODS: AR patients who were undergoing standardized HDM SCIT (Alutard, ALK) between 2018 and 2022 were screened. Those who experienced two consecutive SRs were included in the study group. A control group was established, matched 1:1 by gender, age, and disease duration with the study group, who did not experience SRs during SCIT. Clinical and immunological parameters were recorded and analyzed both before SCIT and after 1 year of treatment. RESULTS: A total of 161 patients were included, with 79 (49.07%) in the study group. The study group had a higher proportion of AR combined asthma (26.8% vs. 51.8%, p < 0.001) and higher levels of sIgE to HDM and HDM components (all p < .001). Serum IL-4 and IL-13 levels in the study group were higher than those in the control group (p < .05). The study group received a lower maintenance dosage of HDM extracts injections than control group due to SRs (50000SQ vs. 100000SQ, p < .05). After 1 year of SCIT, the VAS score, the lung function parameters of asthmatic patients over 14 years old significantly improved in both groups (all p < .05). After a 7-day exposure to 20 µg/mL HDM extracts, the percentages of Th1, Th17, Tfh10, and Th17.1 in PBMCs decreased, while the Tfh13 cells significantly increased in the study group (p < .05). CONCLUSION: The type 2 inflammatory response is augmented in HDM-induced AR patients who experienced SRs during SCIT. Despite this, SCIT remains effective in these patients when administered with low-dosage allergen extracts.

Risk factors for systemic reactions in typical cold urticaria: Results from the COLD-CE study.

BACKGROUND: Cold urticaria (ColdU), that is, the occurrence of wheals or angioedema in response to cold exposure, is classified into typical and atypical forms. The diagnosis of typical ColdU relies on whealing in response to local cold stimulation testing (CST). It can also manifest with cold-induced anaphylaxis (ColdA). We aimed to determine risk factors for ColdA in typical ColdU. METHODS: An international, cross-sectional study COLD-CE was carried out at 32 urticaria centers of reference and excellence (UCAREs). Detailed history was taken and CST with an ice cube and/or TempTest® performed. ColdA was defined as an acute cold-induced involvement of the skin and/or visible mucosal tissue and at least one of: cardiovascular manifestations, difficulty breathing, or gastrointestinal symptoms. RESULTS: Of 551 ColdU patients, 75% (n = 412) had a positive CST and ColdA occurred in 37% (n = 151) of the latter. Cold-induced generalized wheals, angioedema, acral swelling, oropharyngeal/laryngeal symptoms, and itch of earlobes were identified as signs/symptoms of severe disease. ColdA was most commonly provoked by complete cold water immersion and ColdA caused by cold air was more common in countries with a warmer climate. Ten percent (n = 40) of typical ColdU patients had a concomitant chronic spontaneous urticaria (CSU). They had a lower frequency of ColdA than those without CSU (4% vs. 39%, p = .003). We identified the following risk factors for cardiovascular manifestations: previous systemic reaction to a Hymenoptera sting, angioedema, oropharyngeal/laryngeal symptoms, and itchy earlobes. CONCLUSION: ColdA is common in typical ColdU. High-risk patients require education about their condition and how to use an adrenaline autoinjector.

A Complex Evaluation of the In-Vivo Biocompatibility and Degradation of an Extruded ZnMgSr Absorbable Alloy Implanted into Rabbit Bones for 360 Days.

The increasing incidence of trauma in medicine brings with it new demands on the materials used for the surgical treatment of bone fractures. Titanium, its alloys, and steel are used worldwide in the treatment of skeletal injuries. These metallic materials, although inert, are often removed after the injured bone has healed. The second-stage procedure-the removal of the plates and screws-can overwhelm patients and overload healthcare systems. The development of suitable absorbable metallic materials would help us to overcome these issues. In this experimental study, we analyzed an extruded Zn-0.8Mg-0.2Sr (wt.%) alloy on a rabbit model. From this alloy we developed screws which were implanted into the rabbit tibia. After 120, 240, and 360 days, we tested the toxicity at the site of implantation and also within the vital organs: the liver, kidneys, and brain. The results were compared with a control group, implanted with a Ti-based screw and sacrificed after 360 days. The samples were analyzed using X-ray, micro-CT, and a scanning electron microscope. Chemical analysis revealed only small concentrations of zinc, strontium, and magnesium in the liver, kidneys, and brain. Histologically, the alloy was verified to possess very good biocompatibility after 360 days, without any signs of toxicity at the site of implantation. We did not observe raised levels of Sr, Zn, or Mg in any of the vital organs when compared with the Ti group at 360 days. The material was found to slowly degrade in vivo, forming solid corrosion products on its surface.

Exclusive Bee Venom Allergy: Risk Factors and Outcome of Immunotherapy.

INTRODUCTION: Venom immunotherapy (VIT) is considered to be the gold-standard treatment for patients with Hymenoptera venom allergy. Data regarding VIT in bee venom (BV) allergic patients are scarce. AIM: The aim of this study was to evaluate the outcome of VIT in patients with exclusive BV allergy and to try to define risk factors for VIT-induced systemic reactions (VIT-ISR) and VIT failure. METHODS: This is a retrospective study including data from all BV allergic patients that were treated by VIT in the Allergy Unit at the Meir Medical Center in the years 1995-2018. RESULTS: Two hundred and forty-seven patients with exclusive BV allergy were included; 206 (83.4%) preferred to undergo rush buildup. Sixty-nine patients (27.9%) had at least 1 reaction during buildup, with the c-kit mutation being the only significant risk factor (100 vs. 28.9%, p = 0.02). Female gender (25.4 vs. 13.3%, p = 0.04), conventional buildup schedule (26.8 vs. 14.1%, p = 0.04), and c-kit mutation (100 vs. 16.8%, p < 0.01) but not tryptase level were found to be significantly more frequent in recurrent reactors. Females (20.3 vs. 9%, p = 0.03), patients with severe systemic reaction to the index sting (24.3 vs. 9.5%, p = 0.004), and c-kit mutation (66 vs. 12%, p = 0.05) but not tryptase level were found to be risk factors for severe systemic reactions. CONCLUSION: Despite the considerably high rate of VIT-ISR in patients with exclusive BV allergy, VIT can be performed safely and efficiently. C-kit mutation, and not basal serum tryptase level, seems to be a preferable biomarker for VIT-ISR in these patients.

ASIT therapy: advantages and adverse effects. own results and literature data.

OBJECTIVE: Introduction: Allergy is an important medical, social and economic problem nowadays, as it causes disability and patients' quality of life decreases. According to the update data all the existing therapeutic options haven't been used in huge majority of patients. Allergen-specific immunotherapy (ASIT) underuse in particular. One of the reasons for the low frequency of this treatment method using is the fear of systemic and local allergic. The aim of the study was to find out the incidence and severity of adverse reactions in patients receiving subcutaneous and sublingual ASIT. PATIENTS AND METHODS: Materials and methods: In conducted research we compared peculiarities of adverse reactions using sublingual and subcutaneous ASIT methods. Criteria for inclusion in the research were age from 18 to 50 years, diagnosed intermittent or persistent BA. The investigation involved 51 patients with combined basic drug therapy and ASIT, which was performed with injected allergens for 38 patients and sublingual allergens - for 13 individuals. RESULTS: Results: Local reactions were recorded in five patients (13.16%), who received injected ASIT. In four patients (10.52%), dry rales were observed for a short period after injection of the allergen. Local side effect was observed in one patient (7.69%) during sublingual ASIT. CONCLUSION: Conclusions: Adverse reactions, that occur during ASIT, do not pose a threat to patients' lives. However, the therapeutic effect after the year of treatment was significantly better than in patients who used medications only. Modern drugs are safe and, if all the rules are followed, the risk of adverse effects is very low.

Mechanisms Involved in Hypersensitivity Reactions to Polysulfone Hemodialysis Membranes.

Several cases of patients with anaphylactic or systemic hypersensitivity reactions to polysulfone (PS) hemodialysis (HD) membranes and tolerance to cellulose triacetate (CTA) membranes have recently been reported. To investigate the mechanisms involved in PS hypersensitivity, basophil, T cell, and complement activation were analyzed in acute-phase samples from two patients with systemic reactions to PS-based membranes. Basophil and T cell activation, as well as higher serum tryptase levels were detected in acute-phase samples compared with basal levels. Complement levels (C3 and C4) were decreased in acute-phase samples from PS-allergic patients to a higher extent than in samples from control donors taken at the same time points, indicating complement activation during the acute reactions. An experimental external circuit was established on pediatric membranes after rinsing with low or high priming volumes of saline solution, to analyze basophils, T cells, and complement activation in blood samples from 10 PS-allergic and 8 nonallergic HD patients upon contact with PS-based or CTA membranes. Predialysis and postdialysis samples were collected. Basophils from PS-allergic patients exhibited increased degranulation, and T cells showed significantly increased activation after contact with PS-based membranes primed with low volumes of saline. No activation was detected in leukocytes from nonallergic patients under the same experimental conditions. Membrane priming with high volumes of saline abrogated activation of basophils and T cells. However, basophils from allergic donors showed significantly higher responses to Fcεc stimulation after contact with PS membranes. Basophil degranulation and elevated serum tryptase levels in allergic patients during acute reactions support the systemic activation of mast cells and basophils during hypersensitivity reactions to PS-based membranes. A leachable component of the membranes might be responsible for cell activation in some patients.

The safety profile of subcutaneous allergen immunotherapy in children with asthma in Hangzhou, East China.

BACKGROUND: The aim of the current study is to evaluate the prevalence, severity and possible risk factors of systemic reactions (SRs) to subcutaneous allergen immunotherapy (SCIT) in children and adolescents with asthma in Hangzhou, east China's Zhejiang province. METHODS: From January 2011 to December 2016, this survey analysed the SCIT-related SRs involving 429 patients (265 children and 134 adolescents) affected by allergic asthma. Recorded data included demographics, diagnosis, patient statuses, pulmonary function testing results before and after each injection, allergen dosage, and details of SRs. RESULTS: All patients finished the initial phase and six patients withdrew during the maintenance phase. There were 2.59% (328/12,655) SRs in all injections (3.28% in children and 1.47% in adolescents); 15.62% (67/429) patients experienced SRs (18.49% children and 10.98% adolescents). There were 54.57% SRs of grade 1; 42.37% SRs of grade 2; 3.05% SRs of grade 3; and no grades 4 or grade 5 SRs occurred in patients. Most reactions were mild, and were readily controlled by immediate emergency treatment. There was no need for hospitalisation. The occurrence of SRs was significantly higher in children than that in adolescents (p<0.01). A higher ratio of SRs was found among patients with moderate asthma. CONCLUSION: This retrospective survey showed that properly-conducted SCIT was a safe treatment for children and adolescents with asthma in Hangzhou, East China. Children and patients with moderate asthma may be prone to develop SRs.

Dose-dependence of protection from systemic reactions to venom immunotherapy by omalizumab.

BACKGROUND: Systemic reactions (SR) to venom immunotherapy (VIT) are rare but may occur, with a rate significantly higher for honeybee than for vespid VIT. In patients with repeated SRs to VIT it is difficult to reach the maintenance dose of venom and pre-treatment with omalizumab is indicated, as shown by some studies reporting its preventative capacity, when antihistamines and corticosteroids are ineffective. CASE PRESENTATION: We present the case of a 47 years old woman allergic to bee venom who experienced two severe SRs after bee stings and several SRs to VIT with bee venom. Pre-treatment with antihistamines and corticosteroids as well as omalizumab at doses up to 300 mg was unsuccessful, while an omalizumab dose of 450 mg finally achieved in our patient the protection from SRs to VIT with 200 mcg of bee venom. CONCLUSIONS: The search of the dose of omalizumab able to protect a patient with repeated SRs to VIT may be demanding, but this search is warranted by the need to provide to this kind of patient, by an adequate VIT, the protection from potentially life-threatening reactions.

Immunological and clinical factors associated with adverse systemic reactions during the build-up phase of honeybee venom immunotherapy.

BACKGROUND: Adverse systemic reactions (SRs) are more common in honeybee venom immunotherapy (VIT) than in wasp VIT. Factors that might be associated with SRs during the honeybee VIT are poorly understood. OBJECTIVE: Our aim was to evaluate risk factors for SRs during the build-up phase of honeybee venom immunotherapy. METHODS: We included 93 patients who underwent ultra-rush honeybee VIT. The adverse SRs and their severity was compared to various immunological (sIgE, tIgE, basophil CD63 response, baseline tryptase, and skin tests), patient-specific (age, sex, cardiovascular conditions and medications, and other allergic diseases), and sting-specific factors (anaphylaxis severity, time interval to onset of symptoms, and absence of cutaneous symptoms). RESULTS: Twenty-three patients (24.7%) experienced mild SRs and 13 patients (14%) severe SRs. In five patients with severe SRs, the build-up was stopped. High basophil allergen sensitivity, evaluated as dose-response curve metrics of EC15, EC50, CD-sens, AUC, or the response to submaximal 0.01 µg/mL of venom concentration, was the most significant risk factor and only independent predictor of severe SRs and/or build-up stop. Time interval of <5 min after sting to onset of symptoms and lower specific IgEs to rApi m1 was also associated with severe SRs. There was no difference in other immunological, patient-specific, or sting-specific factors, including the baseline tryptase. None of the studied factors was associated with mild SRs. CONCLUSION AND CLINICAL RELEVANCE: High basophil allergen CD63 sensitivity phenotype was a major indicator of severe adverse SRs during the build-up phase of honeybee VIT. Possibly role was also showed for short latency to filed sting reaction and low sIgE to rApi m1. Before honeybee VIT, measurement of basophil allergen sensitivity should be used to identify patients with a high risk for severe side-effects.

Characterisation of systemic reactions to subcutaneous immunotherapy with airborne allergens and classification according to WAO 2010.

BACKGROUND: Systemic reactions (SR) to subcutaneous immunotherapy (SCIT) are rare but potentially severe. The use of different definitions and classifications hampered comparability between studies. AIMS: To determine the frequency of SR to SCIT with airborne allergens, and to characterise and classify them according to the WAO 2010 recommendations. METHODS: Cross-sectional, retrospective study. Data on patients, immunotherapy and SR to SCIT were collected from the SCIT record forms. During the study period, 22,332 SCIT injections were administered (3732 patients). RESULTS: A total of 26 SR (0.1% of administrations) were recorded in 16 (0.6%) patients (median age 22 years, nine males, all with rhinitis and nine with asthma). Twenty-one (81%) SR occurred during the induction phase; eight (31%) in the first hour after administration. According to the WAO 2010 classification, 12 (46%) were grade 1 and 14 (54%) were grade 2. Most grade 2 reactions occurred in asthmatics, presented as mild asthma symptoms and resolved without need for medical observation. Only two individuals without asthma presented grade 2 reactions, both with concurrent cutaneous and low respiratory symptoms; both required medical observation and treatment despite late onset; 82% (n=12) of grade 2 reactions were late. No grade 3-5 reactions were registered and only one patient needed adrenaline treatment. No risk factors for SR to SCIT were identified in this study. CONCLUSIONS: SCIT is a safe treatment when administered by trained staff. The WAO 2010 classification might be useful for retrospectively classifying the severity of reactions, although its usefulness in treatment decision needs further research.

Detection of risk factors for systemic adverse reactions to SCIT with natural depot allergen extracts: a retrospective study.

BACKGROUND: Some patients seem to show a particular propensity to experience systemic reactions (SR) when undergoing SCIT. This study looked at their features. METHODS: 423 adults submitted to subcutaneous immunotherapy (SCIT) with 583 depot allergens extracts were studied. A "slow" build-up schedule was followed, and maintenance doses were given monthly. No mixtures of allergens were employed; multi-sensitized patients were treated with two extracts at the same time. IgE to pollen allergen components were measured. Patients experiencing several SR and those showing repeated large local reactions preventing up dosing were analyzed. RESULTS: Altogether, 14% of patients experienced at least 2 SR to SCIT and further 13% repeated local reactions. All SR involved the skin. Eight treatments were stopped. No reactor was using beta-blockers. SR were not associated with pollen season, use of freshly prepared vials, administration of 2 allergens, or extract producer, nor were preceded by large local reactions. Reactors were younger than tolerant subjects (p<0.05), and females were less frequently fully tolerant than males (p<0.001). The multiple regression analysis showed that both ragweed and grass SCIT were significantly associated with adverse reactions (p<0.001). Specific IgE to Amb a 1 or Phl p 1 did not differ statistically between reactors and tolerant subjects, whereas grass pollen-allergic reactors showed higher levels of IgE to Phl p 5. Intolerance did not depend on the number of primary sensitizations or on hypersensitivity to pollen pan-allergens. CONCLUSION: Young patients or women hypersensitive to grass and ragweed pollen seem at higher risk for SR during SCIT.

Unraveling Complexities: Rhabdomyolysis, Acute Renal Injury, and Compartment Syndrome Following a Wasp's Sting.

This study delves into the rare occurrence of rhabdomyolysis induced by wasp stings, emphasizing its toxic systemic repercussions. Drawing parallels with documented instances of insect bites worldwide, including those by honey bees and Africanized bees, the research explores the correlation between multiple wasp stings and acute renal failure associated with rhabdomyolysis. The venom's active components, such as amines, kinins, and histamine-releasing peptides, underpin toxic systemic reactions, leading to hemolysis, coagulopathy, and severe cytotoxicity-induced acute renal failure. Noteworthy is the emergence of blackish necroses at the sting site, suggesting intense cytotoxicity. The study also highlights skin necrosis as a prognostic indicator for toxic systemic reactions. The presented case manifests an anaphylaxis-like reaction, revealing insights into toxic responses devoid of IgE-mediated allergic reactions. Timely intervention, encompassing hydration, transfusion, and dialytic support, proves imperative in scenarios involving multiple wasp stings, offering successful outcomes documented through plasma exchange in severe cases. This research prompts considerations beyond anaphylaxis, urging exploration of severe toxic systemic reactions in the context of multiple wasp stings.

Comparing the risk of anaphylaxis requiring epinephrine in oral immunotherapy and subcutaneous immunotherapy: A review of recent Canadian real-world literature.

Background: The safety of pediatric food oral immunotherapy (Ped-OIT) has been depicted by some as less favorable than subcutaneous immunotherapy (SCIT) owing to the increased number of serious adverse events requiring epinephrine. A review of real-world data comparing Ped-OIT and SCIT safety is necessary to guide shared decision making. Objectives: Our aim was to compare the safety and adverse event profiles of peanut Ped-OIT and SCIT using Canadian real-word literature. Methods: We performed a retrospective review of recent Canadian real-world literature on peanut Ped-OIT and SCIT safety and adverse events. Results: The incidences of systemic reactions requiring epinephrine were 11 in 270 patients (4.07%) and 12 in 41,020 doses (0.029%) in a multicenter study in British Columbia, Alberta, Manitoba, and Nova Scotia studying 270 preschool-age children treated with peanut OIT. Similarly, a multicenter study in South-Western Ontario examining 160 patients between the ages of 1 and 17 years who were treated with peanut OIT showed that the incidences of systemic reactions requiring epinephrine were 5 in 160 patients (3.1%) and 8 in 52,751 doses (0.015%). A single-center retrospective review of 380 patients receiving aeroallergen SCIT showed that the incidences of systemic reactions requiring epinephrine were 28 in 380 patients (7.4%) and 1 in 1047 injection visits (0.095%). These findings are comparable to those of a review of 860 patients in Ontario who received either aeroallergen or venom SCIT, in which the incidence of systemic reaction requiring epinephrine was 10 in 4242 injections (0.24%). Conclusion: Despite differences in the OIT protocols used and age groups studied, recent real-world data suggest that the safety of preschool peanut OIT or peanut OIT using a slower buildup schedule is comparable to that of SCIT.

Hymenoptera Venom Allergy and Anaphylaxis.

Hymenoptera stings can induce allergic and occasionally fatal reactions, and are responsible for significant morbidity and deterioration in health-related quality of life. The diagnostic work-up must consider the medical history of patients, in the context of venom allergy epidemiology and Hymenoptera taxonomy, and the clinical manifestations of the reactions, to channel the available in vivo and in vitro tests towards the most accurate diagnosis and the consequent appropriate management, also considering the risk profile of the patients on a precision-medicine approach. All these aspects are covered by this work that aims at providing an up-to-date review to increase the awareness of this topic among interested stakeholders, like healthcare professionals and political decision makers, who can contribute to the proper immediate and long-term management of venom allergy and anaphylaxis.

A single center retrospective study of systemic reactions' distribution and risk factors to subcutaneous immunotherapy with dust mite extract in patients with allergic rhinitis and/ or asthma.

To analyze various risk factors including causes that may lead to adverse reactions, especially systemic adverse reactions（SRs）, before and after mite allergen subcutaneous immunotherapy (SCIT), so as to provide real-world reference data for further improving the safety of mite allergen SCIT. Methods: The local adverse reactions（LRs）and SRs of 230 patients with allergic rhinitis and/or asthma who received SCIT in Weifang people's hospital were analyzed retrospectively. The data of patient characteristics, drug factors and environmental elements of adverse reactions were collected and statistically analyzed. Results: There were 28 cases (12.2%) of SRs in 230 patients. All the patients received a total of 7515 injections and 37 SRs (0.49%) were observed. 32.4% (12/37) of SRs could identify their external and subjective triggers. SRs patients had higher 2-year SCIT compliance than no-SRs patients (p = 0.026). The prevalence of SRs in SCIT patients with atopic dermatitis or simple allergic asthma are no statistical significance (P = 0.111). Conclusion: the incidence of SRs in this study is within an ideal range. Through professional patient education and pre injection risk factor assessment, Compliance is still well-controlled and guaranteed although SRs occurred.

Anaphylaxis: Definition, Epidemiology, Diagnostic Challenges, Grading System.

There are many definitions of anaphylaxis in the medical literature. The authors propose a modified definition of anaphylaxis to be used for clinical decision making that promotes the early utilization of intramuscular epinephrine. Anaphylaxis can be a result of an allergic or nonallergic mechanism. In general, allergic reactions are more severe; however, any type of anaphylaxis can result in death and improve with IM epinephrine. The World Allergy Organization's Grading Criteria for allergic systemic reactions are adapted as a guide to identify manifestations that may progress to anaphylaxis. The intent is to promote and encourage the use of IM epinephrine in the health care setting before the progression of manifestations and the onset of life-threatening respiratory or cardiovascular dysfunction generally recognized as meeting the definition of anaphylaxis.

Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy.

Subcutaneous allergen immunotherapy (SCIT) is a proven treatment of allergic rhinitis, asthma, atopic dermatitis, and prevention of Hymenoptera venom anaphylaxis. The known benefit of SCIT, however, must be considered in each patient relative to the potential risks of systemic allergic reactions (SRs). A mean of 1 SR per 1000 injection visits (0.1%) was estimated to occur between 2008 and 2018. Life-threatening anaphylactic events are estimated to occur in 1/160,000 injection visits. The factors that contribute to SRs and fatal reactions (FRs) are reviewed. Risk management strategies are proposed to prevent and decrease future SCIT associated with SRs, anaphylaxis, and FR.

Self-reported reactogenicity of CoronaVac (Sinovac) compared with Comirnaty (Pfizer-BioNTech): A prospective cohort study with intensive monitoring.

OBJECTIVE: CoronaVac (Sinovac) Covid-19 vaccine has recently been approved for emergency use by the World Health Organization. However, data on its reactogenicity in real-world settings is scant. This study aimed to compare self-reported post-vaccination adverse reactions between CoronaVac and Comirnaty (Pfizer-BioNTech). METHODS: We adopted a prospective cohort study design using online surveys from the day of first-dose vaccination with intensive follow-up through two weeks after the second dose (11 time points). The primary outcome was adverse reactions (any versus none) and secondary outcomes were the sub-categories of adverse reactions (local, systemic, and severe allergic reactions). Potential effect modification across multimorbidity status, older age, and sex was examined. RESULTS: In total, 2,098 participants who were scheduled to complete the 14th-day survey were included, with 46.2% receiving Comirnaty. Retention rate two weeks after the second dose was 81.0% for the CoronaVac group and 83.6% for the Comirnaty group. Throughout the follow-up period, 801 (82.7%) of those receiving Comirnaty and 543 (48.1%) of those receiving CoronaVac reported adverse reactions. Adjusted analysis suggested that compared with Comirnaty, CoronaVac was associated with 83%-reduced odds of any adverse reactions [adjusted odds ratio (AOR) = 0.17, 95% confidence interval (CI) 0.15-0.20], 92%-reduced odds of local adverse reactions (AOR = 0.08, 95% CI 0.06-0.09), and 76%-reduced odds of systemic adverse reactions (AOR = 0.24, 95% CI 0.16-0.28). No significant effect modification was identified. CONCLUSION: This post-marketing study comparing the reactogenicity of Covid-19 vaccines suggests a lower risk of self-reported adverse reactions following vaccination with CoronaVac compared with Comirnaty.

The safety of sublingual immunotherapy, can the rare systemic reactions be prevented?

Introduction: The safety of subcutaneous immunotherapy (SCIT), and particularly the dramatic issue of fatal reactions, has been an obstacle that limited the implementation of a therapy with unique characteristics of action on the causes of allergy. The introduction of sublingual immunotherapy (SLIT) was aimed at solving safety problems while maintaining clinical efficacy.Areas covered: For more than 20 years, SLIT has been based on allergen extracts in drops at low average doses. As evidenced by meta-analyses, the typical adverse events (AE) have consisted of local reactions in the mouth and throat. Unlike the injection route, no correlation was observed between the administered dose and AEs. The development of SLIT products in tablets, based on higher doses than drops, has somewhat changed the concept of SLIT safety. Although large trials, performed to obtain regulatory agency approval, have shown overall high safety, rare anaphylactic reactions have been described.Expert opinion: SLIT is globally safe, and no fatal reactions have ever been reported, but with currently available high biological potency products it is necessary to follow prudential rules, such as the administration of the first dose under medical supervision and the thorough education of patients to avoid taking of higher doses than recommended.