Till now, we have heard of vaccines that are given through conventional intramuscular injections. But, did you ever think that they can be delivered to the respiratory tract too? Yes, you read it right. Various researchers in the U.S., Canada and India are working to develop a nasal COVID-19 vaccine that will be given either through a nasal spray or aerosol delivery. Also Read - COVID-19 Alert! Second Wave of Deadly Coronavirus to Hit us in Winter, Will be 'Worse Than First'

As COVID-19 is a respiratory infection, administering a vaccine at the entry point which is nasal cavity, would train the tissue lining it to identify COVID-19 virus and block it from getting through. Also Read - COVID-19: Over 30,000 New Cases in Record Single-Day Spike, Lockdown Extended in States

The scientists are trying to develop a mucosal vaccine that can successfully attack the novel virus the moment it tries to enter the body. The New York Times recently quoted Deepta Bhattacharya, an immunologist at the University of Arizona, stating, “The hope is that mucosal vaccines will do all that their intramuscular competitors can and more, mounting a multi-pronged attack on the coronavirus from the moment it tries to breach the body’s barriers.” Also Read - Aamna Sharif Meets Dipesh Vadodia, a COVID-19 Hero Who's Living Away From His Newborn Daughter For Last 4 Months

Unlike intramuscular vaccination, intranasal vaccines trigger both systemic and mucosal immunity. It also protects other mucosal sites including genital tract, lungs, and intestines.

How Will a Nasal COVID-19 Vaccine Work?

Usually, when a vaccine is administered in your body, it releases B cells and T cells. The former release antibodies called IgG to search for pathogens while the latter either helps the B cells in the production of antibodies or destroy the infected cells.
However, in the case of a nasal vaccine, B cells that are present around the membrane tissues can produce another type of antibody called IgA. Its role is to heel gut and airway pathogens. On the other hand, T cells can remember the features of the pathogens and indulge in patrolling of the place where they first encountered them.