While most countries fell into lockdowns as Covid-19 spread rapidly around the world, Sweden took a different approach and allowed the controlled spread of coronavirus in populations. in an attempt to achieve herd immunity.
They rely on individuals to responsibly create social distance and slow the spread of disease, but, according to a new study published by Journal of the Royal Medical Association, This decision has failed.
“It is clear that not only the rates of virus infection, hospitalization and death (per million of the population) are much higher than rates in neighboring Scandinavian countries, but also the duration of the epidemic in Sweden as well. , with continued extension Professor David Goldsmith, lead author, said: infection and mortality were higher after several critical weeks seen in Denmark, Finland and Norway.
Herd immunity is when a sufficient number of people are immune to a disease, such as Covid-19, the disease cannot be easily transmitted and thus provides indirect protection.
It can be achieved by vaccination or if enough people become ill and develop immunity.
Health authorities predict that 40% of Stockholm’s population will have the disease and have antibodies by May 2020. According to research, the actual prevalence is only about 15%.
They also note that Sweden has a higher rate of virus infection, hospitalization and death compared with neighboring countries.
Goldsmith added that in countries where rapid lock-in measures started in early March appear to be initially more successful in curbing the rise in infection and, therefore, the serious consequences of Covid-19. nationwide.
Sweden has faced a lot of criticism for its controversial decision, especially when the death rate per 100,000 still surpassed the US in July.
Despite this, Sweden’s state epidemiologist, Anders Tegnell, continued to uphold his decision.
Last month, he stated in an interview that there was still no “solid evidence that a shutdown would make much of a difference”. However, he admits too many people have died.
Swedish Prime Minister Stefan Lofven also still supports this strategy, saying that in July he had no doubts about his country’s controversial strategy to go against Covid-19 that remained relevant.
“The right strategy, I’m completely convinced about that,” he said in an interview with Aftonbladet.
And he may be right.
Many experts point out that it is too early to say which pandemic strategy will be the best in the long term.
The authors note that it may not be until two years after the pandemic that we can objectively say which method is most effective.
But new evidence continues to emerge that herd immunity may be harder to achieve than is thought.
For example, clinical and research results show that only severely infected Covid-19 infected patients obtain antibodies during the immediate and early recovery phase of their illness.
Initial research has shown that immunity, even in people with severe infections, may fade away after a few weeks and we have seen cases of reinfection.
Research also shows that less antibodies are found in patients with mild illness or asymptomatic, meaning they most likely are not immune, and therefore cannot prevent the spread of the disease. in the community.
However, according to Evaluation of MIT Technology“Antibodies are not the only way people can fight Covid-19. T cells, which search for and destroy SARS-CoV-2 infected cells, may also provide some protection.
Another problem is that the number of people who need to capture Covid-19 is higher than currently.
Most experts estimate between 40% and 80% of the population will need to be infected. However, as James Hamblin reported in The Atlantic, “the effects of coronavirus are non-linear. Viruses affect individuals and populations in very different ways ”.
“People are exposed to different amounts of viruses, in different contexts, through different pathways. A new species of virus induces more immune responses, ”he wrote.
“Some of us are more susceptible to infection, and some are more likely to transmit the virus once infected. Even small differences in individual susceptibility and transmission can lead to very different outcomes due to the cumulative effects over time, on the scale of a pandemic. “
In other words, the number of people who need exposure to the virus to slow it down could be a lot less.
One researcher, Gabriela Gomes, who studies chaos at Strathclyde University, told Hamblin that to see a decline in Covid transmission, we need only 20% of people to be immune.
This is almost achievable except for the small fact that no one wants to capture it.
As Devi Sridhar, professor of global public health at the University of Edinburgh, told NPR: “Nobody wants to be part of the herd”.
And that is most likely why any attempt to gain herd immunity will fail.