A series of studies by South African scientists have concluded that millions of citizens may have developed a degree of immunity to COVID-19.
Herd immunity defines the protection of a population from a virus through mild exposure to it. This is often done by means of vaccination. While South Africa may have unintendedly developed herd immunity against COVID-19, the World Health Organization (WHO) does not condone achieving herd immunity through public and unmonitored exposure to the virus.
The WHO has gone so far as to say that knowingly exposing people to the virus is “scientifically problematic and unethical.” In answering the public’s questions about COVID-19 and herd immunity, the WHO team said they are still learning about immunity in relation to the virus.
“Until we better understand COVID-19 immunity, it will not be possible to know how much of a population is immune and how long that immunity lasts for, let alone make future predictions. These challenges should preclude any plans that try to increase immunity within a population by allowing people to get infected,” the WHO team said.
In South Africa’s case, the reported potential herd immunity was unintended. After easing lockdown restrictions in September, the country has managed to avoid a second wave of infections unlike other nations around the world.
Where countries in Europe are re-entering lockdown as a result of COVID-19 cases increasing, the South African government has continued to report an unexpected drop in cases.
Studies conducted in the Western Cape and Gauteng provinces have shown that, in some areas, up to 40% of people had developed coronavirus antibodies, with the majority unaware that they had ever been infected.
The Independent reported that although these studies have resulted in a positive outcome, further clinical studies are ongoing to determine how much protection antibodies offer and for how long.
Speaking to Sky News, Shabir Mahdi, a professor of vaccinology at the University of the Witwatersrand, said that he believes the coronavirus had generated a degree of immunity in approximately 12 to 15 million people in South Africa.
"What has happened in SA today, the only way to explain it, the only plausible way to explain it is that some sort of herd immunity has been reached when combined with the use of non-pharmaceutical interventions... like the wearing of masks, physical distancing, ensuring ventilation when indoors, and so on,” he said.
South Africa’s strict lockdown forced people to remain in close proximity with one another, especially in heavily-populated townships that surround the major cities. Citizens were also expected to queue for essentials like food and social security grants during this period.
Researchers believe that these measures created “new networks for the spread of the disease” and helped to fuel a huge wave of infections.
"This inadequacy in terms of adherence of the lockdown, where inadvertently we've had transmission taking place, has resulted in a high percentage in densely populated areas becoming immune,” said Mahdi.
"There might be a question in terms of the duration of immunity... based on our experience with other coronaviruses, a mild infection is probably going to (generate immunity) for two to three years but that places us in a really good position,” he continued.
Mahdi continued to point out that although this result could be positive in the fight against COVID-19, the country’s extended response to the virus needs to be more well-thought out.
"It is not denying that COVID-19 is the most important cause of death this year, superseding HIV, TB, and everything else, but the response needs to be much more nuanced than simply believing that a highly restrictive lockdown is going to get rid of the virus,” he said.