Analysis of Herd Immunity on the Mathematical Model of Covid-19 Transmission

Many countries in the world, especially Indonesia, are still experiencing an increase number of Covid-19 cases despite the government has implemented many policies, such as an appeal for self-prevention, physical distancing, quarantine and large-scale social restrictions (LSSR) in several areas. Besides the health sector, this change in behavior or activity also has a major impact on other sectors such as education, tourism, economy etc. Herd Immunity, where a group in the population is given a treatment so that their body will be resistant to the virus, becomes another alternative to end this Covid-19 pandemic. In this study, we analyzed a mathematical model of corona virus transmission by involving the herd immunity factor. There are two schemes: (1) by using vaccines and (2) by allowing the virus to spread in the population and the result is the infected population have the immunity. The simulation results show that the use of vaccines can drastically reduce the number of infected individuals. On the other hand, the absence of virus transmission control can increase the number of exposed and infected individuals. However, in terms of time, this scheme will make Covid-19 cases decrease faster than other schemes.