Russia has been fighting coronavirus for weeks, but the number of cases is still rising – every day by several thousand.
Now, mass antibody tests are expected to provide more information on the course of the epidemic. Italy is also betting on extensive research of this type to find out the actual number of COVID-19 cases. Thanks to the so-called enzyme-linked immunosorbent assays (ELISA), it is possible to determine who has already been infected with SARS-CoV-2. In addition, the test subjects give a little blood, which is then tested in the laboratory. The result may show the presence of specific antibodies, i.e. IgM and IgG, which the immune system has created to fight the virus. In this case, the sample changes color.
Find out who has become resistant
Mass antibody tests are expected to show who has already developed resistance to COVID-19. In this way, you can find those who have no or only a slight sign of lung disease and who do not know that they are immune to infection.
A person who has already acquired such immunity may, for example, become a blood donor to obtain the serum needed to treat patients with COVID-19. People with detected resistance to SARS-CoV-2 could also work in caring for patients because the risk of reinfection is minimal.
Many antibody tests have an estimated accuracy of around 99 percent. It seems a lot, but in this situation it is problematic. Such accuracy means that one hundredth of people with a positive result may not have contracted this particular type of coronavirus, but another. In the recording for the German public broadcaster NDR, the virologist Christian Drosten explained that it was a so-called “cross-reaction”. In countries where the number of COVID-19 cases relative to the population is not high, deficiencies in test accuracy are more pronounced than where a very large proportion of the population has already had the disease.
Sample research models
Assuming that such a test would be used in a country where half the population is already infected, for every 50 people with positive results there would be only one person who was diagnosed incorrectly. But when only one person in a thousand is actually infected, then out of 10 with a positive result of 9 would have the wrong diagnosis.
Meanwhile, several manufacturers, however, have kept their antibody tests as almost 100 percent effective. Russia had May 26, according to John Hopkins University, more than 350,000 detected infections. With a population of about 150 million, the inaccuracy of such tests plays a very important role. However, testing as many people as possible makes sense, if only to find out how many unreported infections are possible. This may also help in better estimation of the epidemic situation.