New Developments in Climate Change, Air Pollution, Pollen Allergy, and Interaction with SARS-CoV-2

In recent years, the environmental impacts of climate change have become increasingly evident. Extreme meteorological events are influenced by climate change, which also alter the magnitude and pattern of precipitations and winds. Climate change can have a particularly negative impact on respiratory health, which can lead to the emergence of asthma and allergic respiratory illnesses. Pollen is one of the main components of the atmospheric bioaerosol and is able to induce allergic symptoms in certain subjects. Climate change affects the onset, length, and severity of the pollen season, with effects on pollen allergy. Higher levels of carbon dioxide (CO2) can lead to enhanced photosynthesis and a higher pollen production in plants. Pollen grains can also interact with air pollutants and be affected by thunderstorms and other extreme events, exacerbating the insurgence of respiratory diseases such as allergic rhinitis and asthma. The consequences of climate change might also favor the spreading of pandemics, such as the COVID-19 one.

Taxanes Hypersensitivity is not a risk factor for severe reactions to SARS-Cov-2 Vaccines.

Summary: Introduction. The main mechanism involved in hypersensitivity reactions (HSR) to Taxanes (primarily Paclitaxel and Docetaxel) seems to be a complement activation by their excipients: polyoxyethylated castor oil (Paclitaxel) and Polysorbate 80 (Docetaxel). SARS-CoV-2 vaccines contains Polysorbate 80 or polyethylene glycol (PEG) as excipients, which are structurally correlated to polyoxyethylated castor oil. The aim of this study was to verify the presence of a higher risk of HSR to SARS-CoV-2 vaccines in patients with history of HSR to taxanes. Methods. Patients with history of HSR to taxanes were evaluated before the vaccination in our center and underwent skin tests for PEG and Polysorbate 80 (P and P). Some patients completed the vaccination course in other centers without prior P and P skin tests because they had not manifested taxanes hypersensitivity before vaccination, or because those tests were not available. Results. A total of 50 patients were evaluated. 100% of patients with history of hypersensitivity to taxanes completed the vaccine course with no cases of anaphylaxis. 33 patients underwent skin tests for P and P before the vaccination and no correlation was found between P and P skin tests positivity and taxanes skin tests positivity (p = 0.538). 7 patients developed mild symptoms during skin tests and vaccination, similar but weaker than those suffered at the time of the taxane infusion, and independently from the results of skin tests (2/7 positive patients). Conclusions. In our cohort Patients with history of reaction to taxanes were not at higher risk to develop anaphylaxis to SARS-CoV-2 vaccines. However, a common non-IgE mediated mechanism behind those HSRs cannot be completely excluded. This can only account for mild and harmless symptoms in case of SARS-CoV-2 vaccines. Antihistamine premedication and longer observation after the vaccination are still prudent in these patients.