As most countries got stuck as Covid-19 spread rapidly around the world, Sweden took a different approach and allowed the controlled spread of the coronavirus among the population in an effort to achieve herd immunity.
They relied on individuals at a socially responsible distance and slowed the spread of the disease, but, according to a new study published by Journal of the Royal Society of Medicine, this decision has been a failure.
“It is clear that not only are the rates of viral infection, hospitalization and mortality (per million population) much higher than those seen in neighboring Scandinavian countries, but also that the timing of the epidemic in Sweden is different, with persistent persistence of higher infection and mortality well beyond the critical few weeks period seen in Denmark, Finland and Norway, ”said lead author Professor David Goldsmith.
Cluster immunity is when many people are immune to a disease, such as Covid-19, that the disease cannot be transmitted so easily and thus provides indirect protection
It can be achieved either through vaccination or if enough people catch the disease and develop immunity.
Health authorities predicted that 40% of Stockholm’s population would have the disease and gain antibodies by May 2020. According to the study, the current prevalence figure is only about 15%.
They also noted that Sweden had higher rates of viral infection, hospitalization and mortality compared to neighboring countries.
Goldsmith added that in countries where rapid blockade measures were introduced from the beginning of March they appear to be initially more successful in reducing infection and thus the malignant effects of Covid-19 on the country as a whole.
Sweden has faced much criticism for their controversial decision, especially when mortality rates per 100,000 still exceeded the US in July.
Despite this, Sweden’s state epidemiologist, Anders Tegnell, has continued to stand by his decision.
Last month he stated in an interview that there is still “no strong evidence that a deadlock would have made that much change”. However, he acknowledged that many had died.
Swedish Prime Minister Stefan Lofven also still stands by the strategy, saying in July he has no doubt that his country’s highly controversial strategy for fighting Covid-19 remains appropriate.
“The strategy is right, I am fully convinced of that,” he said in an interview with Aftonbladet.
And he might have been right.
Many experts point out that it is still too early to say which pandemic strategy will be best in the long run.
The authors note that it is unlikely that two years after the pandemic we will be able to say objectively which method was most effective.
But new evidence continues to emerge that herd immunity may be harder to achieve than previously thought.
For example, clinical and research findings suggest that only severely infected Covid-19 patients acquire antibodies in the immediate and early recovery phase of their disease.
Early research has shown that immunity, even in those who were severely infected, can weaken after a few weeks and we have seen cases of reinfection.
Research also shows that antibodies are found much less frequently in patients with mild or asymptomatic disease, which means that they are more likely not to be immune, and thus can not stop the spread of infection among the community.
However, according to MIT Technology Review“Antibodies are not the only way humans can fight Covid-19. T cells, which seek out and destroy SARS-CoV-2-infected cells, can also provide protection.”
The other problem is the number of people who have to take Covid-19 is higher than it currently is.
Most experts estimate that between 40% and 80% of the population should be infected. However, as James Hamblin reports in The Atlantic, “the effects of the coronavirus are not linear. The virus affects individuals and populations in very different ways.”
“People are exposed to different amounts of the virus, in different contexts, through different pathways. “A new species virus creates more diversity in immune responses,” he wrote.
“Some of us are more prone to get infected, and some are more likely to transmit the virus after being infected. Even small changes in sensitivity and individual transmission, as with any chaotic phenomenon, can lead to many results. various as complex effects over time, on the scale of a pandemic. “
In other words, the amount of people who need to be exposed to the virus to slow it down can be much less.
A researcher, Gabriela Gomes who studies chaos at the University of Strathclyde, told Hamblin that to see a decline in Covid transmission we only need 20% of people to be immune.
Which almost seems achievable except for the small fact that no one wants to catch it.
As Devi Sridhar, a professor of global public health at the University of Edinburgh, told NPR: “No one wants to be part of the herd.”
And this is most likely why any attempt to achieve herd immunity will fail.