Corona Immunitas Ticino: responding together - the results of the second round of serological test

In light of the second epidemic wave of the SARS-CoV-2 virus, the project Corona Immunitas Ticino - carried out by the Institute of Public Health of Università della Svizzera italiana and SUPSI Department of Business Administration, Health and Social Affairs - has broadened its test population by involving more children (5-13 years), teenagers (14-19 years) and seniors (over 65 years). Between November and December 2020 and early January 2021, 1463 serological tests were performed among participants. Overall, seroprevalence reached 16%, with marked differences by age group, showing an increase compared with the first phase of trials in July 2020.

The Corona Immunitas Ticino study

Starting from July 2020, 8,000 Ticino residents aged between 5 and 104 years were randomly drawn by the Federal Statistical Office and progressively invited to participate in the Corona Immunitas Ticino study, which is part of a national initiative called Corona Immunitas, led by the Swiss School of Public Health (SSPH+). Following the spread of SARS-CoV-2 infections in recent months, USI and SUPSI have worked to expand their population sample further, sending another 5,000 new invitations to children, adolescents and the elderly (aged 65 years and over). All of this was possible thanks to the Institute for Research in Biomedicine (IRB, affiliated USI), SUPSI Laboratory of Applied Microbiology and the Ente Ospedaliero Cantonale (EOC), as well as numerous supporters in the region.

The results of the study

In Ticino, antibodies were detected in 16% of the population, with marked differences between the age groups. In December, the prevalence of SARS-CoV-2 antibodies was 6% in seniors over 75, 7% in seniors between 65 and 74, 12% among children between 5 and 12 and 18% among teenagers.

Professor Emiliano Albanese, director of USI Institute of Public Health, comments: "The data are reliable thanks both to the large participation in the study and to the rigour and reliability of the methods used. More than 90% of our participants reported observing all personal precautions conscientiously (from washing hands to wearing masks to keeping their distance). Keeping schools open may have contributed to positive changes in children and teenagers' behaviour, whose lifestyles involve more social interaction and mobility than the elderly, among whom the virus has circulated much less. Besides, we observed that among younger people, symptoms of COVID-19 are often absent or generic. This may complicate case and contact tracing and thus reduce the effectiveness of quarantine and isolation measures that are likely to have worked well to reduce the risk of infection among the elderly. The spreading of the virus has been contained overall. It is good news, but its downside is that 4 out of 5 children and 9 out of 10 seniors are still at risk. Several statistical analyses are underway to understand how the infection is spread, even within the same household."

Differences with Geneva

The seroprevalence of SARS-CoV-2 antibodies is lower in Ticino, especially compared to the French-speaking cantons. The comparison with the recently published results for the Canton of Geneva is appropriate because the samples were taken in the same period (between the end of November and December 2020). Compared with Geneva in Ticino, the seroprevalence in children and younger seniors is about half. Differences also occur for adolescents and seniors over 75, with 5% less for Ticino for teenagers and 3% less for the elderly.

Collaborations in the region

The Corona Immunitas Ticino project is ambitious. We have established numerous collaborations that have made it possible for us to draw blood samples during the second peak of the pandemic, in particularly vulnerable age groups, and throughout the Canton. In addition to the support of EOC, IRB and SUPSI Applied Microbiology Laboratory regarding the project's activities, particular attention was paid to the young and seniors and their specific needs. Our thank you goes to all the participants of Corona Immunitas Ticino and the many local partners.

Special thanks to: BeeCare home care for the nearly 150 blood samples collected from the participants' homes, the Centro Medico and its branches in Lugano, Chiasso, Bellinzona and Locarno, Hannelore Pieroni's nurses, GIIPSI and the pediatric nursing team, UniTI Health Services, the Sasso Corbaro Foundation, the headquarters of the fire department of Faido, the Biasca headquarters of Tre Valli Soccorso, the protected facility of the civil protection of Acquarossa, the Associazione Ridere per Vivere Ticino and the clown doctors, and finally Migros Ticino and the Ceresio Foundation for their financial support.

Hundreds of samples were collected at the new USI/SUPSI East Campus in Viganello and USI's Academy of Architecture. The spaces made available by USI and SUPSI made it possible to draw blood in complete safety, both for the participants and for the many volunteers involved in data collection, to whom we extend our sincere thank you.

More information on the study at the following link