Local Immunity Concept in the Context of the Novel Corona Viral Infection: A Consideration

The pandemic of novel corona virus disease (covid 19), is presently sweeping the world over. The causative virus is named, SARS-CoV-2. The rapidity with which the pandemic is advancing is catastrophic. That there is no known treatment for this killer disease is throwing public at large into a state of fear psychosis. The urgent need for preventive vaccine is felt now, more than ever before Though promising research is going on, the goal to achieve a breakthrough vaccine is still a long way to go. Since SARS-CoV-2 is an infection restricted to respiratory system of the affected, vaccines aimed at inducing local (mucosal) immunity may offer better chance of preventing the acquisition and spread of the disease to others, than induction of systemic immunity. With this background theme, this article briefly reviewed the epidemiology, the vaccine trials of the Covid 19 as well as the immune responses to viral infection in general and with a special focus on the concept of Local immunity advanced by Prof Besredka (1924). The historical perspective of the local immunity concept is recapitulated and the diseases, both viral and bacterial, to which vaccines are developed in the past basing on this concept are reviewed. A case is made out for applying this concept for the prevention of covid 19. It is suggested that an approach to boost local immunity, than systemic immunity, might be a better strategy of prevention of covid 19.