An ongoing study found that 7.3% of randomly selected people in Stockholm had antibodies when tested in the last week of April.
“These figures reflect the situation in the epidemic earlier in April, as it takes a few weeks for the body’s immune system to develop antibodies,” the agency said in a statement.
Responding to questions about the study at a press conference, national epidemiologist Anders Tegnells said that “just over 20%” in Stockholm may be infected with Covid-19 so far. More than a third of Covid-19 cases confirmed in Sweden are registered in the capital.
A total of 1104 tests were analyzed in the study.
Elsewhere in Sweden, the proportion of people tested for antibodies was much lower, at 4.2% in the far south and 3.7% in the area around Gothenburg.
These results also showed a higher prevalence among people aged 20 to 64 years, of whom 6.7% developed antibodies, than people aged 65 and over, of whom 2.7% developed antibodies.
In the age group under 19, antibodies were approximately 4.7%.
Sweden has not taken the emergency measures to limit the spread of Covid-19 that have been imposed in other European countries, but has called on people to follow the recommendations of hygiene and social distance and to act responsibly.
Sweden’s approach to the Covid-19 pandemic has been criticized both at home and abroad, as the number of Covid-19-related deaths in Sweden is significantly higher than in other Nordic countries, which have set stricter limits.
Sweden said on Wednesday that a total of 31,523 cases of Covid-19 infection and 3,831 deaths had been confirmed in the country.