Mucosal and transdermal vaccine delivery strategies against COVID-19

The years 2020 and 2021 have witnessed a COVID-19 pandemic caused by the SARS-CoV-2 virus. However, these years have also witnessed certain remarkable scientific achievements. Researchers across the globe have been trying extremely hard and accomplished in bringing vaccines a great variety of COVID-19 vaccines. Though the route of administration for the majority of these vaccines has been the intramuscular route (invasive), some laboratories are developing formulations intended for transmucosal and transcutaneous (non-invasive) administration, which are in the early phases of pre-clinical and clinical development. This short report discusses these unconventional formulations against COVID-19, in brief, to stress the importance of research in the field of drug delivery. GRAPHICAL ABSTRACT: [Image: see text]