Coronavirus herd immunity may be ‘unfeasible’: only 5% of people in Spain developed antibodies three months after the pandemic peak, study suggests
- Researchers looked at the blood test results from a nationwide sample of more than 61,000 participants in Spain
- About 5% of people were previously infected with and have built up antibodies to the coronavirus
- In Madrid, seroprevalence was around 10%, while rates in less densely populated coastal areas were below 3%
- At least 60% of people must have contracted the virus in order not to spread it through a community
A new study shows that achieving so-called herd immunity to the new coronavirus may be “unfeasible.”
Researchers found that only five percent of the population in Spain has previously been infected with SARS-CoV-2 and built up antibodies.
However, not enough people have contracted the disease not to be spread in communities.
This means that 95 percent of Spaniards remain susceptible to contracting COVID-19, the disease caused by the virus.
Researchers looked at the blood test results of 61,000 participants in Spain and about 5% have built up antibodies to the coronavirus (photo)
At least 60% of people must have contracted the virus in order not to spread it through a community. Pictured: Healthcare workers move a patient in the Covid-19 unit at the United Memorial Medical Center in Houston, Texas, July 2
Public health officials have been warning for years that vaccines protect not only individuals, but the community as a whole in what is known as ‘herd immunity’.
This happens when the vast majority of a community – between 80 and 95 percent – becomes immune, so that if a disease is introduced, it cannot spread.
Therefore, those who cannot be vaccinated or are at high risk for serious diseases, including the sick, very young and very old, are protected.
The study’s lead author, Dr. Marina Pollán, director of the Spanish National Center for Epidemiology, said CNN the possible immunity rates for herds may even be lower, but we are still nowhere close.
In Madrid, seroprevalence was around 10%, while rates in less densely populated coastal areas were below 3% (above)
Some experts have calculated that about 60 percent of seroprevalence may mean herd immunity. But we are nowhere near that, ”she said.
This was the UK’s strategy – to build the herd’s immunity rather than to lock it up to remove the virus from the community.
Sir Patrick Vallance, the government’s chief scientific adviser, told it Sky News: ‘Herd immunity [allows] enough of us who get mild disease to get immune. ‘
When models showed that the country’s hospital system would not be able to deal with all serious cases, the government declined the plan.
The study, published in The Lancet, recruited over 61,000 participants and adds to the findings of a study also published last month in The Lancet that involved nearly 2,800 participants in Geneva.
In the first phase, conducted between April 27 and May 11, the prevalence of antibodies among residents was given.
In Madrid and the surrounding area, seroprevalence was about 10 percent, while the less densely populated coastal areas were below 3 percent.
The second and third stages showed antibody results of about 5.2 percent.
“The relatively low seroprevalence observed in the context of an intense epidemic in Spain may serve as a reference for other countries,” the authors wrote.
“Currently, livestock immunity is difficult to attain without accepting the additional damage from many deaths among the susceptible population and overloading health systems.”
Only about 0.8 percent of the U.S. population is infected, which Dr. Anthony Fauci, the leading expert in infectious diseases,