An intranasal Covid-19 vaccine will bring about a ‘big positive shift’ in the fight against the pandemic by making the Covid vaccination programme easier and more effective, according to experts. Hyderabad-based Bharat Biotech International has already successfully completed the clinical development of its intranasal vaccine and submitted the data from Phase III clinical trials for approval to National Regulatory Authorities. The response is awaited.   

“Nasal vaccines are going to be a major landmark to contain and manage Covid. The nasal vaccine targets mucosal immune cells, the first line of defence against respiratory infection and, thereby, could prevent people from getting infected in the first place and bringing the infection down,” Sudharshan Jain, Secretary General, Indian Pharmaceutical Alliance, told BusinessLine on Monday. 

Bharat Biotech, the maker of Covaxin, has been working on this development for nearly three years. “It is a great moment for India [if the vaccine is approved],” Jain added. 

Other experts, too, agree on the better efficacy of an intranasal vaccine. Nasal vaccines can be more efficacious to intramuscular ones as they not only act at the systemic level, but also induce a potent local mucosal immune response, which is the first site of entry and replication of virus, thereby blocking it even before it reaches inside of our body,’‘ said Shyamala Iyengar, Senior Consultant Internal Medicine, Apollo Hospitals. 

Though there may be high compliance due to non-invasive methods and ease of administration, the efficacy at an individual level, however, might vary due to various factors such as dosage being delivered, absorption rates and allergic reactions, she added. 

Some experts see a few challenges, too. “The challenges will be in terms of developing an effective nasal delivery system, maintaining antigen stability and residence time in nasal mucosa for stimulating immune response, and also compatibility between vaccine components (antigen and adjuvants),” said a senior doctor at a corporate hospital chain. 

It can easily be taken by the individual and there is no need for any trained personnel, he said, adding: “Compliance will be good, especially for children and elderly.

According to Suchitra K Ella, Joint Managing Director, Bharat Biotech, the intranasal vaccine will make it easier to deploy in mass immunisation campaigns with an easy to administer formulation and delivery device. The vaccine candidate (BBV154) has been developed in partnership with Washington University St Louis, which had designed and developed the recombinant adenoviral vectored constructs and evaluated them in preclinical studies for efficacy. It is a recombinant replication-deficient adenovirus vectored vaccine with a pre-fusion stabilised spike protein.