In the summer of the year 2020, the Chairman and Managing Director of India’s premier vaccine developing company, Bharat Biotech International Limited, told the press that while efforts were on to develop an intramuscular vaccine against Covid-19, what he really would want to do is develop a vaccine that will be easy to administer like ‘polio drops’.
The analogy of polio drops drawn to a vaccine against Covid-19 at that point seemed like a tall order. However, a year later, that vision is coming close to reality and it has got the medical fraternity excited.
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.
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.
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.”
SO WHY IS A NASAL VACCINE BETTER
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.
KILLS THE VIRUS AT THE DOORSTEP
“The nasal route has excellent potential for vaccination due to the organised immune systems of the nasal mucosa,” says Dr Bagai.
“Eight-two per cent of SARSCoV2 transmission occurs through the nasal passage. It takes 6-15 hours for the virus to zone into hAlveolar type 2 cells in the lungs to precipitate the cytogenic release to cause ARDS. The concentration of ACE2R is maxed in the nasal passage. The sentinel cells around the nerves are rich in receptors to cause invasion of the host,” explains Dr Bagai.
“The protein enzyme called Neuropilin is responsible to cause the fusion to host. Neuropilin is in high concentration in sentinel nasal cells. The IgA maximises in the nasal area by 29 per cent. This causes quicker protection and response to the vaccine. Therefore, it’s a very good move,” says Dr Bagai.
COULD IMPROVE VACCINE COVERAGE
Professor Giridhara Babu, a renowned epidemiologist, agrees with Dr Bagai.
“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.
Dr Bagai, a practicing pediatrician, also believes so. “It is an inactivated vector-based vaccine, so it’s safe for children,” he says.
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 on January 19.
[Ack: The above article was written by Ms. Sneha Mordani for INDIA TODAY news website www.indiatoday.in and appeared on 4 March 2021.]
*****
