Results of the most recent wave of the coronavirus prevalence study led by the University of Tartu indicate that almost one in 30 adults in Estonia is currently infected with coronavirus and still contagious. This figure is comparable with the situation at the end of March. However, as the course of the disease is mostly mild, researchers say there is no cause for alarm.
During the study wave from 17 to 29 August, 2,570 adults across Estonia were tested for coronavirus. Of these, 5.5% were infected with coronavirus, but 3.3% (one in 31 adults) was contagious. As also found in the previous study waves, coronavirus prevalence is lowest among those who have recovered from the disease and have also been vaccinated.
The leader of the study, Professor of Family Medicine of the University of Tartu Ruth Kalda said that although the current infection rates are comparable to the end of March, the burden on hospitals is three times lower. "The predominant coronavirus strain is omicron-5, which causes relatively mild symptoms. Therefore, despite the current rather wide spread of the virus, there is probably no need for serious special measures, and we can face the new school year quite calmly," Kalda explained.
The coronavirus antibody prevalence study of this wave included 2,431 adults, 88% of whom had antibodies. Antibodies were found in almost all vaccinated people, 70% of those who have not been vaccinated but have recovered from the disease, and 37% of those who have not been vaccinated nor know to have had the disease. "Antibody prevalence has remained almost unchanged since March. I assume we have reached a certain level that will persist: just as quickly as antibodies disappear from some people's blood over time because it has been a long time since they were infected or had their last dose of vaccine, others will develop antibodies either by recovering from the disease or by vaccination," Kalda explained. However, the prevalence of antibodies in people older than 65 years is close to 95%.
A behavioural survey carried out during the study showed that less and less attention is paid to precautions to prevent the spread of infection. Even though recent data show that almost one in 10 adults has been in contact with an infected person, most of them do not take any action to prevent the further spread of the infection. Kalda noted that although the currently circulating strain tends to cause milder symptoms, it would still be wise for at-risk groups to protect themselves against possible severe disease with a booster dose. "In this respect, the survey data is quite encouraging: nearly half of vaccinated seniors who have not yet received the booster dose plan to do so. Older men are particularly willing to get the booster dose," Kalda said.
According to Mikk Jürisson, the chief executive of the study and Associate Professor of Public Health at the University of Tartu, monthly surveillance is currently the only way to get a complete picture of the prevalence of the coronavirus in the adult population and to assess future trends. "A big thank you to everyone who has agreed to participate in the survey so far or will do so in the future. In such a rapidly changing environment, your willingness to cooperate has provided knowledge-based support in tackling health issues of importance to society as a whole," said Jürisson.
The study on the prevalence of coronavirus is carried out by a broad-based research group of the University of Tartu in cooperation with Synlab Eesti, Medicum and Kantar Emor.
The study is funded by the European Regional Development Fund from the EU measure to respond to the Covid-19 pandemic.
For more information about the study, see the University of Tartu web page.