COVID-19 and delivery of difficult asthma services.

The COVID-19 pandemic necessitated an urgent reconfiguration of our difficult asthma (DA) service. We rapidly switched to virtual clinics and rolled out home spirometry based on clinical need. From March to August 2020, 110 patients with DA (68% virtually) were seen in clinic, compared with March-August 2019 when 88 patients were seen face-to-face. There was DA clinic cancellation/non-attendance (16% vs 43%; p<0.0003). In patients with home spirometers, acute hospital admissions (6 vs 26; p<0.01) from March to August 2020 were significantly lower compared with the same period in 2019. There was no difference in the number of courses of oral corticosteroids or antibiotics prescribed (47 vs 53; p=0.81). From April to August 2020, 50 patients with DA performed 253 home spirometry measurements, of which 39 demonstrated >20% decrease in forced expiratory volume in 1 s, resulting in new action plans in 87% of these episodes. In our DA cohort, we demonstrate better attendance rates at virtual multidisciplinary team consultations and reduced hospital admission rates when augmented with home spirometry monitoring.

Novel freeze-dried DDA and TPGS liposomes are suitable for nasal delivery of vaccine.

There is a pressing need for effective needle-free vaccines that are stable enough for use in the developing world and stockpiling. The inclusion of the cationic lipid DDA and the PEG-containing moiety TPGS into liposomes has the potential to improve mucosal delivery. The aim of this study was to develop stable lyophilized cationic liposomes based on these materials suitable for nasal antigen delivery. Liposomes containing DDA and TPGS were developed. Size and zeta potential measurements, ex vivo, CLSM cell penetration study and cell viability investigations were made. Preliminary immunisation and stability studies using ovalbumin were performed. The liposomes exhibited suitable size and charge for permeation across nasal mucosa. DDA and TPGS increased tissue permeation in ex vivo studies and cell uptake with good cell viability. The liposomes improved immune response both locally and vaginally when compared to i.m administration or control liposomes delivered nasally. Additionally, the lyophilized products demonstrated good stability in terms of Tg, size and antigen retention. This study has shown that the novel liposomes have potential for development as a mucosal vaccine delivery system. Furthermore, the stability of the lyophilized liposomes offers potential additional benefits in terms of thermal stability over liquid formats.