The architect of Sweden’s no-lockdown strategy said up to 30% of its population could now be immune to COVID-19, a claim not supported by data

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Anders Tegnell of the Public Health Agency of Sweden at a news conference about the coronavirus on July 30. ALI LORESTANI/TT NEWS AGENCY/AFP via Getty Images
  • The head of Sweden’s lockdown-free coronavirus response, Anders Tegnell, claimed in an interview with The Observer that as many as 30% of the country’s population could be immune to COVID-19.
  • But studies have found much lower rates of antibodies in the Swedish population – for example, data in June indicated that about 10% of people in Stockholm, the worst-affected region, had COVID-19 antibodies.
  • It is also not yet clear to what extent having antibodies protects a person from catching COVID-19.
  • Visit Business Insider’s homepage for more stories.

The architect of Sweden’s lockdown-free coronavirus strategy claimed that almost a third of the country’s population could now be immune to COVID-19 – a theory not backed up by any hard evidence.

Anders Tegnell, the chief epidemiologist at Sweden’s Public Health Agency, told The Observer on Sunday that the recent drop in Sweden’s cases could mean there is an immunity level in the population of “20%, 30%, maybe even slightly more in some areas.”

Tegnell has been widely credited as the architect of Sweden’s unusual response to the coronavirus pandemic, in which the country decided not to institute a widespread lockdown and put in place relatively few restrictions.

He made the claim about immunity while trying to explain the drop in Sweden’s cases over the past month.

Sweden coronavirus
People sit in the Tantolunden park in Stockholm on May 30. HENRIK MONTGOMERY/TT News Agency/AFP via Getty Images

Tegnell said that seasonal factors like schools and offices closing for Sweden’s summer holidays were not on their own enough to explain the drop in cases.

“Exactly why this happened at that time and why it was so quick and sudden, is difficult for us to understand,” he said. “But we believe that the increasing number of immune people in the population must have something to do with it.”

Despite Tegnell’s theory, researchers have so far reached few solid conclusions on immunity to COVID-19.

People who catch a virus usually have antibodies, which can be measured by tests. But it’s not clear whether having antibodies offers total – or even partial – immunity to COVID-19, or how long such an effect may last.

Studies measuring antibody levels in Sweden have not been nearly as high as the 20% or 30% cited by Tegnell.

In June, data from its Public Health Agency indicated that about 10% of people in Stockholm, the worst-affected region, had antibodies.

Tegnell said in April that he expected 40% of people in Stockholm, Sweden’s capital, to be immune by the end of May.

A study in late May suggested that 6.1% of Sweden’s population had developed coronavirus antibodies.

Tegnell told The Observer the reason that studies had not supported his thesis is that it’s hard to get a good sample.

“It’s very difficult to draw a good sample from the population, because obviously, the level of immunity differs enormously between different age-groups between different parts of Stockholm and so on, and that’s why when we measure one group we get 4% to 5%, and when we measure another group they’re up to 25%,” he said.

Some virologists in Sweden have rejected the theory that cases are falling because of more immunity.

As of Monday, more than 5,700 people had died of the coronavirus in Sweden, a figure far higher than in neighbouring countries with similar political systems and social customs.

Its per-capita death figure is more than five times Denmark’s, more than 11 times Norway’s, and almost 10 times Finland’s.

Jan Albert, an infectious-diseases expert at Sweden’s Karolinska Institute, told Business Insider last week that Sweden could see further spikes in virus cases, particularly as the summer holidays end.

“We definitely have come down from a peak, but whether we will see an increase again later in the year, especially when workplaces and schools open up again, we don’t know,” Albert said.

“It’s likely that we will see at least smaller outbreaks and possibly some kind of second wave or peak.”