The results of the prevalence study led by the University of Tartu show that the number of coronavirus infections has decreased considerably over a month, but the wave is not over yet. The coverage of adult population with antiviral antibodies remains fairly unchanged.
During the study wave from 27 April to 9 May, 2,380 people were tested, of whom 4.4% tested positive. A number of them had already had Covid-19 and posed no infection risk to others, but 1.5% of all the tested adults were still infectious. This is nearly half as many as during the prevalence study wave at the beginning of April. The prevalence of the infection is consistent regardless of the age and gender of the participants, and those who are an infection risk tend to have symptoms.
According to the leader of the prevalence study, the University of Tartu Professor of Family Medicine Ruth Kalda, the decline in infection is noticeable, but unfortunately not so marked yet as to suggest the end of the coronavirus wave.
The results of the study continue to confirm that those who have not only had the disease but have also been vaccinated are best protected against the virus. Also, the infection rate among those vaccinated with a booster dose is twice lower than among those who completed the standard vaccination course.
To assess the prevalence of antibodies, 2,228 people gave samples during this study wave, and 86% of them had antibodies. This figure has remained almost unchanged over the month. Those who have been vaccinated have the most persistent protection by antibodies. Three quarters of those who have contracted the virus and recovered have got antibodies. “This shows that post-exposure antibodies are less persistent and disappear quicker than those obtained by vaccination,” said Kalda.
The behavioural part of the study reveals that people’s sense of safety has declined and they are paying less attention to safety precautions. The majority of people who have been in contact with an infected person do not take any steps to prevent the spread of infection. According to the chief executive of the study, University of Tartu Professor of Public Health Mikk Jürisson, the arrival of sunny spring weather is not enough to end the virus. “Now is the right time to supplement the standard vaccination course with a booster dose and thus curb the spread of the virus. The higher vaccination coverage we can achieve in society during the summer, the further it will delay the onset of the next infection wave when the new virus season arrives,” Jürisson explained.
The prevalence study is carried out by a broad-based research group of the University of Tartu in cooperation with Synlab, Medicum and Kantar Emor. It is the only study that provides an overview of the actual prevalence of the coronavirus in the adult population.
For more information about the coronavirus prevalence study, see the University of Tartu website.
The study is funded by the European Regional Development Fund from the EU measure to respond to the Covid-19 pandemic.