The intramuscular route of vaccine administration has been considered as the ultimate way of vaccination. However, intranasal vaccines come with several advantages, such as ease of self-administration and induction of mucosal and systemic immunity. intranasal vaccines are different from intramuscular vaccines in the way they are administered and under what settings.
Nasal mucous is the human body’s first line of defence, and hence it is highly immuno-efficient. Pathogens have to pass through this mucous wall to enter the body. Some studies suggest that when a small dose of antigen is delivered into the nasal mucosa, it can cause a rapid and potent immune response. Altimmune is developing a non-replicating adenoviral vector vaccine named AdCOVID. On 10 May, the Company announced encouraging findings from a preclinical study in a novel coronavirus challenge model of infection. In this study, a single dose of intranasal vaccine provided sterilizing immunity in the lungs of vaccinated mice.
Oxford University and AstraZeneca (LON:AZN) are investigating the nasal spray form of their ChadOx1 vaccine. On 25 March, Oxford University revealed that the Phase 1 clinical trial would enrol approximately 30 healthy individuals aged between 18 to 40 years. Covaxin-manufacturer Bharat Biotech is also developing an intranasal COVID-19 vaccine named BBV154. BBV154 is a novel intranasal, adenovirus vector vaccine being developed to combat COVID-19.