There are two lines of immunological defence in the vertebrate immune system: The innate and adaptive immune system. These two are related, the innate being the evolutionary oldest, and the functional basis of the adaptive immune system. The innate immune system is able to handle small and local infections. A small bolus of Corona COVID-19 virus, say about 20 viral units, in small, airborne drops from the breath of a healthy infected person, is normally handled without any symptoms. Still this gives immunological learning and immunity. If the innate immune system is handling the small boluses of virus, there is no antibodies to detect. This means that only the people who have a weak innate immune system will have an asymptomatic infection which calls for the second line of the immune defence, the adaptive immune system response with antibodies. It is therefore very likely that every single person living in a city is being infected with COVID-19. Therefore, the number of infected people are likely to be 100 times larger than estimated from random population tests testing for Corona (inclusive COVID-19) using antibody tests. Therefore, all the numbers of infection fatality rates (IFR) we are collecting these days from all countries must be set 100 times lover than estimated by World Health Organization and other authorities using the present Corona test to estimate the mortality of COVID-19. Furthermore, if we include the resent findings from large autopsy studies of people who died with COVID-19 showing that there are no people dying from COVID-19, we are forced to set IFR=0.
It is well known to all immunologists that there are two lines of immunological defence in the vertebrate immune system: The innate and adaptive immune system (1-4). It is also well known how these two are related, the innate being the evolutionary oldest, and the functional basis of the adaptive immune system.