Résumé
Background: During the initial rollout of COVID-19 vaccination in Singapore, the Ministry of Health (MOH) issued recommendations that patients with a history of any previous vaccine allergy be referred to an allergist for further review on suitability to proceed with mRNA-based COVID-19 vaccines. We review the evaluation of these patients with suspected vaccine allergies prior to receiving mRNA-based COVID-19 vaccines. Method(s): Between 8 April and 22 September 2021, 304 patients were evaluated prior to receiving the COVID-19 vaccinations. Of these, 63 (20.7%) patients with suspected immediate hypersensitivity reactions to non-COVID polysorbate-containing vaccines proceeded to have skin prick test (SPT) and Intradermal test (IDT) to polyethylene glycol (PEG)-3350, polysorbate 80 and polysorbate 20 containing products. Another 62 (20.4%) who reported delayed hypersensitivity reactions to polysorbate-containing vaccines proceeded to have direct inoculation (DI) of the Pfizer BNT162b2 vaccine under the supervision of an allergist. The remaining 242 (76.6%) finally assessed not allergic polysorbate-or tolerated previous non-polysorbate- containing vaccines were recommended to proceed with COVID-19 vaccinations at the community vaccination sites. 99 patients in the SPT/IDT and DI group completed a questionnaire-based survey to report any post vaccination reactions. (Figure 1) Results: Of 63 patients who underwent SPT/IDT, 2 (3.2%) with equivocal IDT tolerated both doses of the BNT162b2 vaccine without major allergic reactions. 61 (6.8%) patients with negative SPT/IDT and 62 (100%) in the DI group completed both doses of BNT162b2 vaccination without major reactions. Among those who completed the questionnaire survey, 13 (13%) reported reactions including non-specific rashes and mild urticaria/angioedema post first dose vaccine. All subsequently completed the second dose of the BNT162b2 vaccine following allergist review;with 8 (61.5%) reporting similar mild skin reactions. Conclusion(s): Majority of those with suspected reactions to polysorbate containing vaccines are able to tolerate the BNT162n2 vaccine which contains PEG-2000. Skin tests prior to mRNA COVID-19 vaccination is unnecessary. Those who report mild potentially allergic reactions after the first dose are able to tolerate the second dose of the BNT162b2 vaccine.
Résumé
Plastic waste caused by the extensive usage of face masks during COVID-19 pandemic has become a severe threat to natural environment and ecosystem. Herein, an eco-friendly approach to repurpose face mask waste for clean water production via solar thermal evaporation is proposed. By taking advantage of its interwind structure, face mask holds the promise to be an ideal candidate material for constructing photothermal evaporator. In-situ surface modifications are performed successively with polyvinyl alcohol and polypyrrole to improve its wettability and solar absorption (97%). The obtained face mask-based evaporator achieves significantly enhanced solar efficiency (91.5%) and long-term salt-rejection stability. The harvested clean water befits plant growing to enable farming on sea surface. A floating photothermal evaporation prototype is then developed to demonstrate autonomous solar ocean farming, with plants successfully cultivated over time. As such, the proposed strategy provides a promising solution towards ecological sustainability by tapping multiple benefits.