In an updated prognosis, Tom Britton, a professor of mathematics at Stockholm University, has predicted that Stockholm will achieve herd immunity against the novel coronavirus in June.
According to his new mathematical modelling, herd immunity may be achieved with 40-45 percent of the population having contracted the coronavirus, instead of 60 percent, as previously stated. However, due to a slower spread, this will only happen in mid-June instead of May, as predicted earlier, Britton explained to the newspaper Svenska Dagbladet.
“We have used a simple model with the reproduction number 2.5 (when each person on average infects 2.5 people) and concluded that the flock immunity occurs at about 40-45 percent instead of 60 percent,” Britton said.
While another research team, led by Gabriela Gomes of the Liverpool School of Tropical Medicine, has landed at an even lower percentage where flock immunity can appear, Tom Britton is somewhat sceptical.
“They have come up with figures of 10-20 percent, but I don't believe that. The important thing is that the percentage is substantially lower than 60,” Tom Britton said.
The more people have had the virus and become immune, the more difficult it becomes for the virus to spread in a population. But if flock immunity is not achieved before restrictions are lifted, a second wave of infection is expected.
Sweden's state epidemiologist Anders Tegnell found the prognosis that Stockholm may reach herd immunity in June plausible.
“Yes, but I think we have to be careful about what we mean by herd immunity. Still, that does not mean that the danger is over. We will still have a lot of spread, but at a lower level,” Anders Tegnell said. “It is not a signal that everything can return to normal,” he added.
So far, Sweden has seen 26,322 confirmed Covid-19 cases, nearly 5,000 recoveries and 3,225 deaths and remains the hardest-hit Scandinavian nation. Unlike its fellow Nordics, Sweden has consistently resisted mandatory lockdowns and stringent measures, instead relying on mostly voluntary precautions based on mutual trust between the authorities and the population.
Still, Sweden's relaxed approach appears to have hit home with the population, as the ruling Social Democrat party's support has exceeded 30 percent for the first time in months, after having dipped into the low 20s. State epidemiologist Anders Tegnell enjoys near-rock stardom and is celebrated with memes, T-shirts and even tattoos. There is a Facebook group called Anders Tegnell's fan club with over 30,000 members.