NEW DELHI, Oct 12: So far there is no medicine to treat coronavirus nor any vaccine ready for mass immunisation even as globally the virus has claimed over a million lives in the past few months since it started in Wuhan in China in December last. Currently there are around 200 intramuscular vaccines in various stages of development, a few of them in the final clinical trials.

Oral and intramuscular administration are the common methods of vaccination till date. However, the global healthcare crisis created by the devastating new pathogen has prompted research on intranasal vaccination as an alternative mode which is being considered as more convenient and effective route especially because it can be self-administered.

The new coronavirus inoculation is similar to the nasal spray for flu immunisation. It is being developed in the US, UK and Hong Kong. A dual flu-covid nasal spray vaccine is also to start human trials next month in Hong Kong, according to reports.

The nasal vaccine candidates currently being tried are using SARS-CoV-2 spike protein. It had produced better results in animal studies. It will be less invasive and is quickly absorbed by the nasal mucosa. Production and administration (by self) is also cheap and affordable.

Respiratory viruses enter through the nose and the nasal mucosa is the primary area for the generation of abundant copies of its genome by entering the human cell in instant time. From the nasal mucosa it moves along the airway during inhalation into the airways and the lungs, the ultimate target of the virus.

The nasal mucosa is the first barrier the respiratory diseases-causing microbes encounter. The immune-competent mucosa lines over the sinus, airways and the lungs. As nasal mucosa is the primary breeding ground for the corona, it makes sense in strengthening the mucosal immunity through mucosal antibody secretion by nasal vaccination unlike intramuscular vaccination which creates systemic response. Nasal inoculation can also prevent transmission.

Additionally, nasal vaccination does not cause fear of diseases transmission through needles and anaphylactic response associated with injections. In self-administration, the vaccine cost also will come down drastically.