Corona Immunitas Ticino, the first results are in
Institutional Communication Service
29 September 2020
The first results of the Corona Immunitas Ticino project, conducted by the Institute of Public Health of Università della Svizzera italiana and the Department of Business Administration, Health and Social Affairs of SUPSI, are in. A seroprevalence of SARS-CoV-2 of 11% has been registered in the Ticino population between 20 and 64 years of age.
The Corona Immunitas Ticino study
As of July 2020, 8,000 people in Ticino aged between 5 and 104 years were randomly selected 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 Ticino. The initiative is led by the Swiss School of Public Health (SSPH+) of which USI and SUPSI are founding members and is supported by the Federal Office of Public Health, several cantons and a number of companies. The study aims to measure the spread of SARS-CoV-2 virus, the development of immunity, the social and economic impact and the consequences of the epidemic on mental and physical health. Thanks to a cutting-edge system of data collection and management, Corona Immunitas Ticino also allows a weekly and monthly monitoring of the trend of COVID-19 symptoms, the perception of risk, and the behaviours that can help reduce the risk of contagion.
A test of the highest quality
In order to measure the presence of antibodies specific to SARS-CoV-2 in blood, the study uses a serological test developed by the Centre Hospitalier Universitaire Vaudois (CHUV) in collaboration with the Swiss Federal Institute of Technology in Lausanne (EFPL) and the Swiss Centre for Vaccine Research. The test is particularly appropriate for population studies, and it provides accurate and reliable data during all phases of the epidemic, not only the acute one. Blood samples were taken in July at EOC Hospitals from specific population groups. The serological tests were then conducted by the Institute for Research in Biomedicine (IRB), affiliated to USI, and the Laboratory of Applied Microbiology of SUPSI, and repeated in the laboratories of CHUV. Samples that tested positive for antibodies were those of participants who have been infected with the virus and have developed an immune response.
The results of the first phase of the study
Thanks to the high quality of the test and the large number of people taking part in the study, it was possible to determine that among the 210,000 adults living in Ticino, about 23,000 have come into contact with the virus. It is worth underlying that only 2,000 cases have been reported in our Canton since the beginning of the epidemic. It is worth underlying that only 2,000 cases have been reported in our Canton since the beginning of the epidemic. The first phase of the study, involving the adult population between 20 and 64 years of age, was attended by 1,300 people who continue to participate in weekly and monthly online questionnaires on the evolution of the epidemic and how its impact changes over time. The serological test was performed on more than half of the participants (647). The Corona Immunitas study at national level uses the same test, the same methods and the same procedures, thus allowing to compare the results of Ticino with those of the other cantons. The presence of antibodies specific to SARS-CoV-2 was detected in 11% of the samples in Ticino. It is the highest figure at the national level. More in detail, in Canton Vaud a seroprevalence of 7% was recorded, in Basel of 4% while in Zurich, it drops to 3%. Another interesting data concerns the regional diversity of the seroprevalence in the Ticino region. In Locarno the figure is just over 15%, in Bellinzona around 10%, and all other areas are somewhere in between these two figures. Looking at the data by age group, women in Ticino between 20 and 35 years of age have a seroprevalence that rises to 18%, while in the group concerning adults between 50 and 64 years of age (both men and women) the seroprevalence is around 10%. The study conducted by the Cantonal Doctor's Office between May and July (corresponding to Phase 1 of the pandemic) used a different test, and it showed a seroprevalence of 9%. This shows that more than two out of every hundred people came into contact with the virus in the meantime, which would translate at the level of the Ticino population into more than 4,000 people between 20 and 64 years of age.
The next steps of the project Corona Immunitas Ticino
These results confirm that Ticino is not only able to keep up with the national initiative of the SSPH+, but it also plays a fundamental role in the study because it has been strongly affected by the pandemic. The result of seroprevalence among adults represents the first step in a long journey. Corona Immunitas Ticino carries on. In addition to monitoring the population aged between 20 and 64 years for a whole year through questionnaires, the serological tests may be performed again to contribute to a better understanding of possible risk factors and related mechanisms of contagion and spread of the virus. Besides, since September 2020, the second phase of the project has begun, involving 2,000 people under 20 years of age and 2,000 people aged 65 years and over. Very little is still known about these two population groups. Only a large and representative sample will allow us to deepen what is happening among school-age children and the elderly. The challenge is ambitious, and participation is crucial. Those who have been randomly selected are asked to answer the online questionnaires or, for seniors who wish to do so, over the phone, and to take the serological test. At this stage, special attention is given to the intergenerational aspects of this epidemic, including the risks and modalities of contagion, and changes in relationships between different generations. For this reason, all participants are offered the opportunity to invite to join the study people under 20 or over 65, with whom they have had regular contact in recent months.
Thanks to the valuable contribution of the numerous participants, it will be possible over twelve months (July 2020 to June 2021) to measure the impact, consequences and implications of the COVID-19 epidemic in Ticino on individuals, communities, and society at large, and to assess immunity in the Canton's population.
For more information about the study: www.corona-immunitas-ticino.ch