Published 14:06 IST, May 14th 2020
Explainer: As Sweden attempts to achieve herd immunity against COVID, here's what it means
While Sweden has not officially declared its goal of achieving herd immunity, an absence of lockdown and open bars attracted the attention of lockdown sceptics.
As novel coronavirus spread from China to the rest of the world within few months forcing countries to impose strict lockdown, one European country, Sweden, decided to ditch the lockdown enforcement and took a different approach. While most other countries closed non-essential businesses, schools and restaurants in a bid to contain the spread of the pandemic, Swedish people are still ‘enjoying drinks’ and snacks at their favourite bars though with lax social distancing measures in place. What looks like a fault on the surface is, in fact, an effort to achieve 'herd immunity', experts believe.
While Sweden has not officially declared its goal of achieving herd immunity, an absence of lockdown and open bars attracted the attention of lockdown sceptics who believe 'the world should follow Sweden's model'. However, WHO, on the contrary, warned against these relaxed measures on May 14 and said ‘humans are not herds’. The UN agency added that ‘we will lose some old people along the way.’
What is herd immunity?
The term ‘herd immunity’ has been used by epidemiologists to describe a population immune to the disease and can help protect its most vulnerable individuals. However, such immunity is usually achieved by ensuring that a large enough percentage of the population is vaccinated. In the presence of such herd immunity, the virus finds is hard to spread and eliminates gradually.
Herd immunity helps build a broad base of recovered infections in society and the disease eventually dies as there are fewer susceptible people. This is because the virus essentially runs out of hosts to infected. Herd immunity can be achieved either when large enough percentage of a population contracts a disease and recovers leaving a trail of immunity behind or through vaccination. In the case of coronavirus, there is still no vaccine and hence this option remains unavailable until a vaccine is developed. Most scientists believe herd immunity is achieved when more than 60 per cent of the population has had the virus.
Risks and red flags
Herd immunity, as experts suggest, should be achieved through a vaccine to ensure little human cost. However, in the case of coronavirus which does not have a vaccine yet, it can only be achieved by allowing people to fall sick, recover and gain immunity. Simply put, getting people sick can kill them as well. Many experts believe that herd immunity, without a vaccine, comes with an 'unacceptable' human cost and is risky.
Another problem is that coronavirus blood tests, which check whether a person has developed antibodies, are coming back negative. As per WHO, very few people have shown evidence for antibodies.
"A very low proportion of the people that have been tested have evidence of antibodies," Maria Van Kerkhove, the WHO's technical lead for COVID-19, said. "The range is between 1 and 10%."
WHO’s executive director of health emergencies Mike Ryan also said that primary assumption of some is that this disease that has spread around the world will affect most of the people and this will all be over. He added that on the contrary “the preliminary results from the sero-epidemiologic studies are showing the opposite”
“The number of people infected in the total population is probably much lower than we expected."
Another problem with determining herd immunity in case of coronavirus is that there is no definite proof of recovered patients developing immunity. In fact, on the contrary, as many as 222 patients of COVID-19 again tested positive in South Korea after recovering.
Sweden’s Corona strategy: What’s allowed, what's not?
Sweden has kept its restaurants and nightclubs open with some social distancing measures in place. Schools are also open for children under the age of 16 and as many as 50 people can gather at a time. Other countries in Europe certainly have far more strict measures where large gatherings are restricted to 10-15 people only.
However, Sweden Is shutting bars and clubs that do not follow social-distancing norms. The government has reportedly also advised senior citizens to venture out only in case of emergency. However, it remains a voluntary decision. The government also urged public to avoid mass transit and peak hours and stores were asked to limit the number of people allowed. Sports organisations were advised to cancel upcoming matches and competitions. Furthermore, a gathering of more than 50 people is also banned.
Is Sweden coronavirus free?
By no means! As of May 14, Sweden has recorded as many as 27,909 confirmed cases and 3,460 deaths among its population of 10.3 million people. Sweden has a higher coronavirus death rate per million citizens than that of the United States, and its coronavirus death toll is considerably higher than its Nordic neighbours with strict measures.
Sucess of the relaxed measures?
On May 8, Sweden’s state epidemiologist Anders Tegnell reportedly said in a briefing that there has been a degree of control over transmission as the country has been “very much alert and saw cases very early on." He added that Countries to Sweden’s south suffered, “partly because they didn’t see the slow beginning of the epidemic” and started “testing too late.”
Tengnell further attributed the decline in cases in Stockholm to a level of "immunity in the population.” According to Sweden’s public health agency, a third of Stockholm’s residents may have already contracted the virus which marks a process towards 'herd immunity'. Herd immunity, if achieved, makes a county more resilient if it is hit by a second wave.
WHO: “Humans are not herds”
Taking a veiled jibe at Sweden, WHO on May 12 said that the “herd immunity” approach is “dangerous”. WHO’s executive director of health emergencies Mike Ryan didn’t mention the name of any country but said that it can lead to the death of ‘a few old people along the way.’ Most people who have succumbed to coronavirus in Sweden are over 60 years of age.
“This idea that, ‘Well, maybe countries who had lax measures and haven’t done anything will all of a sudden magically reach some herd immunity, and so what if we lose a few old people along the way?’ This is a really dangerous, dangerous calculation,” Ryan said on a call with reporters.
Ryan described herd immunity as a policy which is “concerned with the overall health of the herd, and individual animals in that sense, doesn’t matter”. He added, “Humans are not herds.”
"I think we need to be really careful when we use terms in this way around natural infections in humans, because it can lead to a very brutal arithmetic which does not put people, and life, and suffering at the center of that equation," he added.
Meanwhile, Sweden, on May 13, extended its recommendation to avoid non-essential overseas trips until July 15. Foreign Minister Ann Linde warned that further extensions may still come. The advice was initially issued on March 14t for two months and has been extended for the second time.
Updated 14:06 IST, May 14th 2020