Covid-19 tests: a little clarity to avoid mistakes

Key words: Covid-19 tests, Serological tests, Immunity, Coronavirus

There is confusion on the role of the available Covid-19 tests. While serological tests give information on the passage of the virus (did I get infected?), the swab describes the current situation (am I infected?). The information on the occurred contact with the virus helps to estimate the likelihood to be infected and to prevent the further spread of the disease. Particular attention is to be paid to the specificity of a serological test that, if it is not sufficiently close to 100%, can produce a worrying number of false positive subjects. Therefore, this type of tests is more useful to monitor the prevalence of the infection in the community rather than to give a misleading immunity “license” to individuals.