Dr Krishan Ella's Bharat Biotech has started the process of screening potential clinical trial participants at four centres in India - Nagpur, Hyderabad, Patna and Chennai for their new nasal vaccine against Covid19.

As per Bharat Biotech's website, "An intranasal vaccine stimulates a broad immune response neutralising IgG, mucosal IgA, and T cell responses and creates an immune response at the site of infection (in the nasal mucosa) essential for blocking both infection and transmission of Covid-19."

What are the benefits of having an intranasal vaccine

Cost-effective

"It will be cheaper and cost-effective and there would be ease of administration with no injections," says Dr Sanjeev Bagai, an avid vaccine watcher and chairman at the Nephron Clinic in Delhi. Bharat Biotech has said that the scalability to manufacture this would help meet the global demand.

Non-invasive/Ease of administration

That it is non-invasive and needle-free is an added advantage. The nasal vaccine will not require trained healthcare workers as it would go inside the nasal cavity like drops. This would also eliminate the injuries and infections associated with needles.

Could improve vaccine coverage

"A vaccine administered intranasally, if approved after clinical trials, will be a game-changer. Some of the adverse effects related to vaccination can be attributed to how injections are administered. An intranasal vaccine, if proved to be free of adverse effects, will help in improving the vaccine coverage. Since the virus harbours in the nasopharynx, it will be interesting to examine its efficacy in inducing local immunity. If yes, then this might turn out to be better than other vaccines in terms of preventing the infection," says Professor Giridhara Babu.

Safe and suited for children and adults

"The nasal vaccine can have high compliance as it would be ideally suited for children and adults," says Bharat Biotech.

Single dose

The developers at the Bharat Biotech are working towards a single-dose intranasal vaccine. Such a vaccine, if approved, would also help slash down logistics and cost. The company has said that mice, hamsters and macaques were immunised from SARS-CoV-2 after they were given a single dose of ChAd-SARS-CoV-2-S. Viral clearance was observed in both lower and upper airways in all these animal models, the company said.

Thus, the company said, the intranasal immunisation of ChAd-SARS-CoV-2-S can create an immune response in the nose, which is the point of entry for the virus—thereby protecting against disease, infection and transmission.

Bharat Biotech received the approval to start the phase 1 clinical trials of the vaccine and the process of recruitment, sources say, will take two to three days and we can expect the trial to start by early next week. The number of subjects in the first phase of the nasal vaccine trial would be 125. The product on trial is BBV154, a novel adenovirus vectored, intranasal vaccine.