The number of Belgians with antibodies against the novel Coronavirus (COVID-19) in their blood has not increased in recent weeks, and remains at 6.9%, according to a study by the University of Antwerp (UAntwerpen).
In Sweden, with less strict lockdown restrictions than Belgium, the percentage of people in the Stockholm region sampled for antibodies in their blood was 7.3% by the end of April.
To ensure immunity in a population, the herd or group immunity rate would have to reach 60 % or more but according to a global overview it remains a distant hope.
Issuing the findings of the vast serological study on Friday, UAntwerpen researchers said strict measures imposed by the Government had considerably limited the spread of the virus.
UAntwerpen began the study in March, based on residual blood samples in laboratories. The samples were drawn every three weeks from persons throughout the country who were not admitted to hospitals and who, therefore, had no special link with the virus.
“Tests on 3,253 blood samples show that 6.9% of Belgians have resisted the virus,” researcher Heid Theeten said.
In late March, 3% of Belgians were found to have antibodies in their blood. Three weeks later, 6% had them, but in the third phase, the increase has been minimal. “We can therefore say that the seroprevalence has stopped increasing,” Theeten said.
“Between the first and second phase, we observed a stronger increase for people aged between 20 and 29 years, and for the over-80s,” she added. “Now these groups, too, are no longer showing an increase.”
The third phase of the study focused on samples drawn between 18 and 25 May.