Serological tests in Ticino: the first results

A project was launched to test on a voluntary basis those who are potentially more exposed to SARS-CoV-2: healthcare workers. From 16 April volunteers have been tested in Ticino for antibodies generated by the new coronavirus infection. Coordinated by the Clinical Trial Unit EOC (CTU-EOC), the project is carried out in collaboration with hospitals, COVID-19 centres in Ticino (Ente Ospedaliero Cantonale EOC and Moncucco Clinic), the Institute for Research in Biomedicine (IRB, affiliated to USI) and Humabs BioMed (a subsidiary of Vir Biotechnology). Participation has been strong throughout the region: from the 4,728 serum samples collected it was possible to carry out serological tests and obtain the first results in less than a month. Antibodies were detected in 9.73% (460) of the samples likely indicating exposure to SARS-CoV-2, responsible for COVID-19 infection. The project involved the medical staff of EOC, Cardiocentro Ticino and Transfusion Service with a total of 4334 collaborators, Hildebrand Clinic (294 collaborators) and Moncucco Clinic (100).

"The participation in the study and the speed with which it was carried out, in regard to the collection of data and blood samples, and analysis, is remarkable. We can say that we met, or even surpassed, the standards of other similar initiatives at a national level," says Prof. Dr. Alessandro Ceschi, Director of CTU-EOC. "In addition to the sound and efficient coordination, the feedback and generosity of the volunteer health workers from all the structures of the Canton must be acknowledged. Thanks to them, we now have data, which we will further examine in the coming days, to help clarify the epidemiological situation of the canton in a population potentially at risk and which will help to define our future strategy in this setting. They also represent a good starting point for further in-depth studies on the population, some of which are already underway", adds Prof. Dr. Ceschi.

"The serological test used at the IRB was developed by Humabs BioMed and is able to measure the presence of antibodies against the part of the new coronavirus that is responsible for the infection in the host cells. Validation trials have confirmed the high specificity and sensitivity of the test", explains Prof. Federica Sallusto, Laboratory Director at the USI-affiliated Institute of Bellinzona. "In any case, it is important to remember that the presence of specific antibodies still does not allow us to determine whether an individual is protected, partially or totally, by a re-infection. For this reason, it will be important to continue to monitor the donors who have developed the antibodies in order to evaluate their evolution and persistence and for this reason, we count on the extraordinary collaboration of the volunteers who have joined the study", explains Prof. Sallusto.

"The chance to monitor over time the donors who have developed the antibodies gives us a unique opportunity to also deepen our knowledge on the immunological response to SARS-CoV-2 by analysing the cellular immune response, which is an equally important element of the body's defense against coronavirus", explains Prof. Dr. Paolo Ferrari, Head of Medical Area at the EOC.

Prof. Emiliano Albanese, Director of USI Institute of Public Health adds that "this work is part of a set of projects developed by researchers from Ticino to assess and address the consequences of COVID-19 infection, in collaboration with national and international partners and health authorities. Among these are population-based studies that will allow to extend the study to a larger sample of the population."