Leave it to the Swedes – who zigged when everyone else was sagging in the wake of the global pandemic – to question the conventional wisdom that so-called non-pharmaceutical interventions (NPIs) saved the day in the battle against the SARS-CoV-2 virus.
In a paper published Tuesday at MedRxiv, Marcus Carlsson, a senior lecturer in mathematics at Lund University, and Cecilia Soderberg-Naucler, a professor of medical microbial pathogenesis at Karolinska Institutet, contend that while there could be “some protection against SARS-CoV-2 under current NPI-levels,” NPIs don’t begin to explain the behavior of the waves of COVID-19 infections caused by the virus in Sweden.
Instead, they argue, “some sort of pre-immunity needs to be
taken into account” to explain infection and death rates in Stockholm county – ground zero for the disease in the Scandinavian country.
Sweden was hit hard by COVID-19, but not nearly so hard as it was expected to be hit.
Shortly after the pandemic began in 2020, Uppsala University used a then-popular model for infection forecasting from the Imperial College London to predict that 80,000 Swedes would die by July if the country didn’t join the rest of Europe in imposing lockdowns and other drastic NPIs.
The Swedish government, however, refused to lock the country down. The infections that followed hit hard, but the deaths were in the thousands not tens of thousands.
Still, there were enough people dying in 2020 that then-President Donald Trump in April of that year Tweeted that “Sweden is paying heavily for its decision not to lockdown. As of today, 2,462 people have died there, a much higher number than the neighboring countries of Norway (207), Finland (206) or Denmark (443). The United States made the correct decision!”
Most of the U.S. was then locked down and masked up. Despite that, the death rate in the U.S. Northeast was skyrocketing. The disease has now killed about 100,000 people in the states of New York, New Jersey and Massachusetts.
Seeking to explain how the death rate could be lower in a country that employed minimum restrictions than in countries that imposed major restrictions, Carlsson and Soderberg-Naucler argue the only logical explanation is that some sort of inherent immunity protected a significant segment of the Swedish population.
They readily admit this flies in the face of conventional wisdom and further express fears it could be used by people in other countries to argue against the imposition of NPIs.
“About a year ago, a number of different researchers put forward the idea that pre-immunity or immunological ‘dark
matter’ could lurk behind the unexpected unfolding of the COVID-19 pandemic,” they write, “but as time went on this dark matter was not found and along with various erroneous predictions involving pre-immunity, the hypothesis seems to have been discarded.
“This could also be related to a fear of causing unnecessary deaths related to political implications of such scientific findings, connected with the Great Barrington Declaration and a small group of scientists pushing for the removal of NPI’s and mitigation strategies . If a level of pre-immunity would exist it would give fuel to that flank of the “scientopolitical discourse.”
The Great Barrington Declaration originated with professors from Oxford University in the United Kingdom and the Harvard and Stanford universities in the U.S. It argues for allowing “those who are at minimal risk of death to live their lives normally to build up immunity to the virus through natural infection while better protecting those who are at highest risk.”
The low-risk group is generally considered to be those 40 or 50. The infection fatality rate for COVID-19 has been found to rise steadily with age going from 0.002 percent for children under age 10 to 0.01 percent for those at age 25 to 0.4 percent at age 55 and 4.6 percent by age 75, according to a peer-reviewed meta-analysis in the European Journal of Epidemiology.
As with all studies posted at MedRxiv, the Swedish study has not been peer-reviewed, but then again there are indications the “scientopolitical discourse” the Swedes mention is making of science the mess that journalism has become
Scientists studying “replication” at the University of California San Diego this year discovered that, as the UC San Diego News Center headlined, “Research that is Less Likely to be True is Cited More (Often).”
“The link between interesting findings and nonreplicable research also can explain why it is cited at a much higher rate – the authors found that papers that successfully replicate are cited 153 times less than those that failed,” the website reported.
It could also be that they are cited more often due to the confirmation bias of researchers wanting to buttress their own non-replicable research in a world where politics has infiltrated just about everything.
Carlsson and Soderberg-Naucler hint that politics played a role in the disappearance of the “dark matter” hypothesis, and that “it is too early to discard the hypothesis that some sort of pre-immunity needs to be taken into account, in particular for accurate mathematical modeling.”
Their models more accurately predict what happened in Stockholm country when pre-immunity is factored into the equation, they say, and explain the waves of infection that country has experienced.
…”Most scientists observing this time series (of waves) would conclude that NPI’s along with voluntary behavioral changes in the population made the second wave bend downwards in early November, and then guess that public weariness and/or mutant strains caused the third wave, which again bent downwards due to renewed public compliance with recommendations in the face of the recent surge.
“Indeed, this is the by now accepted scientific consensus among
scholars studying the pandemic, which is sometimes called ‘herd-protection’, and builds on the simple idea that when a major deadly epidemic hits, society reacts….”
Unfortunately, they add, “the pandemic response in Sweden challenges this interpretation” because the Swedes employed very few NPIs.
In other words, they didn’t react to infections rates going up or down. They just went on doing what they were doing.
“If, as we argue here, the Stockholm cases have plummeted twice due to depletion of susceptibles linked to pre-immunity, rather than variation to the NPI’s and public compliance thereof, it is a question of semantics whether to call it herd-immunity or something else,” they write. ” The point is that the restrictions in Sweden are very relaxed and that society is functioning practically as normal, with banning of major gatherings and bars/restaurants closing early as the only main limitations, and a large part of the population is acting as if the virus didn’t exist.”
In this scenario, they suggest the massive number of deaths that were predicted never happened because up to 62 percent of Swedes were protected by some form of pre-immunity.
“As mentioned earlier, we provide evidence that previous Influenza A infections could have provided such high protection rate against SARS-CoV-2,” the write. “However, we believe that this manifests itself in large variability of susceptibility to SARS-CoV-2, and not sterilizing immunity.
“Confirming this hypothesis will require further studies,
as other viruses may also mediate a protective pre-immunity. Furthermore, genetic factors may also provide different protection on an individual level due to differences in the innate and adaptive immune response against this virus . In
particular, the 62% could easily drop to some lower value if people start exposing themselves to higher risk or if a virus
variant appears which has the ability to circumvent the mechanisms behind this phenomenon. Indeed, the data from India seems to suggest that pre-immunity to Delta is significantly lower. In summary, we prefer to not sum up the two immunity
variables since it may give a false illusion of a high degree of protection in society.”
And a popular belief in a high degree of natural protection would definitely complicate the aforementioned “scientopolitical discourse,” which has already caused Sweden enough problems.
“Sweden’s health authorities were resigned to mass infections -so called herd immunity…,” Bjorkland wrote. “And the result has been deadly. While countries such as the United States, Brazil, and India have made headlines for recording the highest number of coronavirus-related fatalities, Sweden’s death rate of over 80 per 100,000 people is among Europe’s highest and is around 10 times as great as those of Norway and Finland, and over four times Denmark’s. COVID-19 hospitalizations are now rising faster there than in most European countries, and Sweden is caring for more patients in hospital now than it did at the height of its first wave. By Dec. 21, Sweden had surpassed the United States and all major European countries in its daily confirmed cases per million.”
Sweden did witness a large infection rate in December, but the case fatality rate (CFR) – the number of people dying as a result of those infections – also dropped significantly.
After that wave of infections subsided in May another began and peaked near the end of April at rate about eight times that of the first wave in May and June of 2020, but the CFR was a fraction of what it was in early 2020.
Sweden was witnessing roughly 600 to 700 new cases per day in April and May of 2020 and 30 to 100 deaths. By April and May of this year, the infection rate was up to 2,000 to 8,000 cases per day, but only 15 to 20 people were dying.
When Carlsson and Soderberg-Naucler modeled what happened in Sweden and then ran the model into the future, what they found were waves of steadily decreasing size as the disease becomes endemic. The pattern appears much like that of the flu in the wake of the Spanish flu pandemic more than 100 years ago.
“A weakness of this hypothesis is that it is not clear which factor or combination of factors that causes the pre-immunity,” they admit, “and it is certainly not clear whether pre-immunity is long-lasting or whether it also wanes over time, which changes the
modeling in the longer perspective.
“Nevertheless, it is interesting to see how the model behaves in the long run in the absence of both vaccinations and future mutations….As is plain to see, recurring waves become milder and milder to finally level out at a constant rate of around 700 new infections per day, equalling 29 cases per 100,000 per day.
“Put differently, this means that every person will get COVID-19 with cycles of about 10 years. Another interesting observation is that alpha (variant) completely takes over and the ‘original strain’ never comes back. It is likely that the Indian variant delta will have the same effect on alpha in Sweden and generate a new wave during the fall, as seems to be the case in Great Britain at the time of writing.”
Whether the COVID-19 vaccines, which have to date proven amazingly effective, can eliminate the disease or simply move it to the endpoint of the Swedish model, or some lower endpoint, only time will tell.