COVID 19: Herd Immunity Projection in Bangladesh

Abstract

Herd Immunity is the opposition to the spread of infectious disease like COVID-19 within a population that appears if an adequately high proportion of individuals are immune to the infectious disease. According to infectious disease law, if at least 70 percent of a population becomes resistant to a particular disease or infectious disease, they can no longer spread the disease to the remaining 30 percent of susceptible people. If 70 to 90 percent of total populations in a country are infected by COVID-19, then herd immunity will be obtained and by this way the novel corona virus can be annihilated from that country. According to the World Health Organization, a person infected with corona virus can infect 2.5 people. At least 90 percent of people need to be infected with corona virus to have herd immunity. If there is to be herd immunity in the case of Bangladesh, there are 161.4 million people here, so about 145.5 million people will have to be infected with corona virus. If the infection continues in Bangladesh, there is no way out until herd immunity comes. If Bangladesh makes a decision to go to herd immunity, it is necessary to know the death and infected status in herd immunity stage. In this paper, a model based on Malthusian theory has proposed to make the projection of herd immunity with the status of infected cases, cured cases and death in Bangladesh. The model of exponential growth has implemented to evaluate the time of herd immunity and also to estimate the total death and infected cases. The proposed model has validated using MATLAB and Microsoft excel.