CURRENT ALLERGY & CLINICAL IMMUNOLOGY JOURNAL OF THE ALLERGY SOCIETY OF SOUTH AFRICA
Vol 35, No 1 March 2022
- Developing vaccines to combat human diseases: A history
- COVID-19 vaccines: Adverse events following immunisation
- Allergic sensitisation in South Africa: Allergen-specific IgE-component testing
- Ethical issues with vaccination against COVID-19
- Occupational rhinitis and asthma resulting from lentil and split pea allergy in a food handler
Authors: Robin J Green
Abstract: Many authors have suggested that one of the most important contributing factors to the enhanced survival of the human population over time has been the vaccination of children. You only have to think of polio and how vaccination spared generations of that disease. Naturally, though, improvements in environmental status, such as favourable living conditions and improved quality of life, have also played an important role in this.
DEVELOPING VACCINES TO COMBAT HUMAN DISEASES: A HISTORY
Author: David P Moore
Abstract: This article traces the development of vaccines from the early attempts to combat a fatal disease caused by variola (smallpox) virus in antiquity, through to the highly technical advances which have led to the efficacious vaccines targeting COVID-19. As vaccine preparation has advanced, so has the understanding of the immune response to immunisation and the realisation that the use of adjuvants is essential to boosting the immune response. Furthermore, coupling polysaccharides to proteins is important in achieving vaccine efficacy in young children and older adults. Successful vaccination programmes have led to marked reductions in mortality associated with the diseases targeted by those vaccines – and to the unintended consequence of cultural amnesia regarding those diseases. The anti-vaccination movement has gained traction by riding on this cultural amnesia to capitalise on spurious associations, infrequent public-health disasters around inadvertent administration of faulty vaccine preparations and rare adverse events to build a case against vaccination. This tension between the advances in vaccine production and the criticism cast at the pro-vaccination agenda should be viewed as an agent for growth in the development of safe and effective vaccines, and in the planning to combat future pandemics.
Keywords: vaccine development, human disease, vaccine history
COVID-19 VACCINES: ADVERSE EVENTS FOLLOWING IMMUNISATION
Author: Sylvia van den Berg, Cathy van Rooyen, Pieter F Wessels, Marieke Brauer, Robin J Green
Abstract: Patients rely on healthcare providers as their most credible and frequent source of vaccine information. It is therefore crucial that healthcare providers are informed and have evidence-based, objective and clear guidance on vaccine efficacy and specific adverse events following immunisation (AEFI). Reported serious AEFIs are extremely rare for the COVID-19 vaccines. This article discusses the main AEFIs attributed to COVID-19 vaccines, including neurological complications of Guillain-Barré syndrome (GBS) and acute transverse myelitis (ATM), thrombosis; cardiac complications, including myocarditis, pericarditis and cardiomyopathy; and allergic reactions such as anaphylaxis, urticaria and skin rashes. The benefits of COVID-19 vaccination outweigh the risks; however, it is important that healthcare providers are aware of the risks and know how to recognise and manage them.
Keywords: COVID-19 vaccine, adverse events, Guillain-Barré syndrome (GBS), acute transverse myelitis (ATM), thrombosis, cardiac complications, myocarditis, pericarditis, cardiomyopathy, vaccine allergy, urticarial, skin rash
ALLERGIC SENSITISATION IN SOUTH AFRICA: ALLERGEN-SPECIFIC IGE-COMPONENT TESTING (ISAC)
Author: Louise Murray, Cathy van Rooyen, Sylvia van den Berg, Robin J Green
Background: Allergic sensitisation patterns differ globally; therefore it is important to understand local South African sensitisation patterns to inhalant and food allergen components to enable clinicians to diagnose and manage South African patients appropriately.
Methods: A retrospective study was conducted reviewing component allergen testing data from a private laboratory provider in South Africa over a two-year period. Data generated from all Immuno Solid-phase Allergen Chip (ISAC) tests referred from all regions in South Africa were collected and analysed according to the allergen-component positivity rate.
Results: A total of 813 consecutive patients were tested for allergen-component sensitisation by ISAC testing. Data were assessed to determine the most prevalent sensitisation patterns for inhalant, food and cross-reactive allergen components. The most frequent inhalant allergen components were Bermuda grass (Cyn d 1) and Timothy grass (Phl p 1), followed by cat uteroglobin (Fel d 1) and house-dust mite (HDM) (Der f 1). Peanut (Ara h 2), shrimp (Pen m 2) and egg white (Gal d 1) were the most prevalent food-component allergens. The most common pollen–food cross-reactive allergen components were cross-reactive carbohydrate determinant (CCD), profilin and thaumatin-like protein (pathogenesis-related protein (PR-5)).
Conclusions: Grass pollen components were identified as the most common inhalant allergen sensitiser. The most common pollen–food cross-reactive component sensitisation was to CCD, which is in keeping with the high level of grass pollen sensitisation. HDM-component sensitisation was lower than expected when correlated with previous studies using whole allergen specific IgE sensitisation data. This study contributes to understanding allergen sensitisation patterns in South Africa by adding component sensitisation data to the current diagnostic knowledge pool; and it raises awareness of the extent of allergen-component cross-reactivity in South Africa.
Keywords: allergic sensitisation, allergen-specific IgE-component testing, sensitisation patterns, inhalant, food allergen component
ETHICAL ISSUES WITH VACCINATION AGAINST COVID-19
Author: Charles Feldman
Introduction: A common framework used in the analysis of medical ethics is the ‘four principles’ approach of Tom Beauchamp and James Childress, whose book, Principles of Biomedical Ethics, was first published in 1985. Their four principles include autonomy, beneficence, non-maleficence and justice:
- Autonomy – the right of the patient to accept or refuse any therapy or intervention recommended to them, which embodies informed consent.
- Beneficence – indicates that a practitioner should always act in the best interests of the patient.
- Non-maleficence – ‘first, do no harm’ or ‘above all, do no harm’ (primum non nocere).
- Justice – includes distributive justice, which deals with the distribution of scarce medical resources.
ALLERGIES IN THE WORKPLACE
OCCUPATIONAL RHINITIS AND ASTHMA DUE TO LENTIL AND SPLIT PEA ALLERGY IN A FOOD HANDLER
Authors: Zahida Sonday, Shahieda Adams, Tanusha Singh, Edith Ratshikhopha, Mohamed F Jeebhay
Background: A machine operator at a factory that packages raw forms of legumes and grains developed work-related ocular-nasal and asthma symptoms associated with exposure to legume dust at work. Despite earlier sensitisation, he developed ingestion-related symptoms to lentils much later, after tolerating exposure for years.
Methods: Work-related symptoms were evaluated clinically and by means of a walk-through inspection to ascertain the extent of exposure to legume dust. Respiratory function assessment entailed spirometry accompanied by a bronchodilator challenge and serial peak flow monitoring. Immunological evaluation included investigation for atopy using Phadiatop and skin-prick tests to common aeroallergens, specific IgE reactivity to potential workplace legume and grain food allergens as well as other potentially cross-reacting food agents. SDS-PAGE and immunoblot testing were used to determine the molecular weights of the putative allergen using food samples obtained from the factory and the serum of the index case.
Results: Occupational asthma was confirmed based on the finding of airway reversibility and a positive work effect index score of 3.73 in the presence of sensitisation to different lentils and split peas. The molecular weights of potential allergens were identified as being a ~50 kDa protein (possibly Len C 1 and Pis s 1 respectively), one between 75–100 kDa and another of 25 kDa. There also appeared to be cross-sensitisation to other legumes, notably chickpea.
Conclusion: This rare case of occupational legume (lentil and split pea) allergy resulting in occupational rhinitis and asthma highlights the role of inhalant workplace food allergens and the need for improved workplace dust control measures and exposure standards in the food industry.
Keywords: work-related asthma, occupational food-induced allergy, lentil allergy, split pea allergy, inhalational legume allergy
NON-DISCLOSURE OF HEALTHCARE INFORMATION TO MINORS
Author: Sharon Kling
Abstract: The disclosure of healthcare information to patients is essential for them to be able to make informed decisions. Non-disclosure usually comes from a place of good intention and aims to promote the patient’s good (beneficence) and prevent harm (non-maleficence) by not disclosing grim or poor prognoses. Parents wish to shield their children from receiving bad news, but often this is detrimental to their health. The healthcare professional has a role to advocate for disclosure to the child, in so doing promoting the child’s developing autonomy.
Keywords: non-disclosure, healthcare information, minors
ABC OF ALLERGY
CLASSIFYING HYPERSENSITIVITY REACTIONS
Authors: Shaunagh Emanuel, Di Hawarden
Abstract:Our immune system is designed to protect us, but sometimes, when it over-reacts to harmless substances, causes damaging inflammation, or reacts against us, it can cause harm or even death. In 1963 Gell and Coombs classified immunologic hypersensitivity reactions into four types according to pathophysiology. As we have gained a better understanding of the extraordinary workings of the immune system, this classification has been expanded, but the foundation remains relevant. Dr Do-a-lot asks her students to discuss the classification of hypersensitivity reactions.
DR SPUR’S MY STERY CASE
A MYSTERY CASE AS OLD AS TIME
Authors: Louise Murray, Sylvia van den Berg, Cathy van Rooyen, André van Niekerk
Abstract: Dear Dr Kagiso, thank you for your kind referral. This is indeed a complicated case and she is definitely a candidate for further workup.
It is important to investigate her immune system, because she has suffered from several severe and recurrent infections. I always advise clinicians to think of me (Dr Spur) when they are dealing with a patient suffering from infections. Think SPUR – Severe, Persistent, Unusual, Recurrent infections. These should prompt clinicians to investigate the immune system further. They are important warning signs of a possible underlying immunodeficiency.