ABSTRACT
World, especially Indonesia, is experiencing pandemic virus infection called Corona Virus Disease-19 (COVID-19) or Severe Acute Respiratory Syndrome Corona Virus-2 (SARS CoV-2). COVID-19 was firstly outbreak in Wuhan City on December 31 2019, having major receptors on Angiotensin Converting Enzyme-2 (ACE-2), especially located on lungs. One of its transmissions due to droplet and bioaerosol transmission,its attachment by the Spike 1 (S1) protein, and the invasion process by Spike 2 (S2). Invasion process stimulates host immunity resulting in excessive cytokines-chemokines production (cytokine storm) that has negative effect on the lungs, Acute Respiraatory Disease Syndrome (ARDS), and death. The New Normal phase is a new habit living with COVID-19 must be applied by community so that it reaches the treshold (Ro and Pc) on Herd Immunity and life postCOVID-19. There is a simple model that describes the components involved in Herd Immunity, namely: susceptible people exposed and recovered from COVID-19. © 2021 UPM Press. All rights reserved.