A recently published follow-up study by Tyrolean researchers shows that in April 2022, approximately 96 percent of blood donors in Tyrol had antibodies against the coronavirus. The broad study, which can draw on data from about 73,000 blood donations, shows a sharp increase compared to the autumn of 2021, when antibodies could only be detected in 83 percent of donors.
For example, the majority of this meaningful cross-section of the population had antibodies, either from a corona vaccination or a corona infection, according to Peter Willeit, professor of clinical epidemiology at the Medical University of Innsbruck.
lower chance of infection
“However, this does not mean that these people are fully protected against future infections,” emphasizes Willeit. But: “We know from previous studies, for example in the Schwaz district or abroad, that the chance of infection is lower with higher antibody levels”.
Therefore, in the current study, which has access to data up to June 2020, it is important to measure the level of antibody levels, the epidemiologist said. “The average level has more than quintupled since the fall of 2021,” Willeit said, according to a result of the survey, which ended in April 2022.
Antibody levels 16 times higher in vaccinated individuals
The vaccination status in terms of antibodies and antibody levels is still decisive. “In the last month of the study, only two-thirds of people who stated they had not been vaccinated when donating blood had detectable antibodies, compared with 99.7 percent of those who had been vaccinated,” he explained. In addition, the antibody level in vaccinated people has been shown to be about 16 times higher on average.
Important findings for further research
The research results provide an important basis for further studies, noted Harald Schennach, head of the blood bank at the Tyrolean Clinics. Especially because the number of people being tested for antibodies is so large: “By the end of the year we expect to evaluate a total of 100,000 tests”. In any case, it is hoped that this collaboration between the blood bank and Peter Willeit can continue, according to Schennach.
Together with the corona wastewater data, the corona antibody tests form an important monitoring system. The state of Tyrol, which promotes the study and research, would be supported in its measures, according to the head of the blood bank.