A mutant strain of the new coronavirus discovered in South Africa appears to be able to fend off antibodies from individuals who have previously recovered from COVID-19 – meaning that if the new strain spreads, we may see more people being infected multiple times.
A group of South African scientists made this discovery in an article published earlier this week by the National Institute of Communicable Diseases in South Africa. In it, researchers describe how they studied blood samples from a small group of people who developed COVID-19 , but ended up recovering. When the human body recovers from a disease, it produces a protein known as an antibody to identify and ultimately protect itself from the bacteria or virus that caused it in the future. (These disease-causing microorganisms are known as pathogens.) This means that people who were sick with COVID-19 should, in theory, have antibodies that recognize the pathogen that causes it and neutralize it in case they are reinfected.
Instead, according to the article’s authors, half of the blood samples from the patients tested did not contain the antibodies needed to protect them from the new coronavirus strain 501Y.V2, identified in South Africa last month. Although it was a small study and more research needs to be done, the initial results are not auspicious.
This can not only interfere with the human population’s ability to develop natural immunity, but it can also undermine the effectiveness of the Pfizer and Moderna vaccines. Both companies are distributing mRNA vaccines, which are different from traditional vaccines that train the immune system to develop antibodies against pathogens, injecting weakened or dead versions of the disease-causing agents into the body. MRNA vaccines, on the other hand, inject a synthetic single-stranded RNA molecule that infects our own cells and makes them produce the protein that grows at the “peak” outside the coronavirus. The presence of this protein in the body is then recognized as an intruder, and the immune system learns to identify the coronavirus as an enemy and to protect itself against it.
In the case of the COVID-19 vaccines, both train the body to recognize a SARS-CoV-2 virus protein known as Spike. Spike is the protein that helps the virus to enter human cells and resembles small pins that protrude from the sphere of the virus itself, like the spines that protrude around a sea urchin. Unfortunately, the South African mutation alters this same protein, which means it can affect the vaccine’s effectiveness.
The South African strain is not the only one that causes concern. There is a new strain in Brazil that scientists argue “also has changes in key positions” in ways that can impair the effectiveness of antibodies against the disease. Then there is a strain in the UK known as B117 which, while not more lethal than previous strains, is more transmissible.
“I think transmissible is definitely the right word because it highlights what we know and what we don’t know,” said Dr Dylan Morris, a UCLA postdoctoral researcher, to the Salon earlier this month about the British strain. “Even if the severity of the disease is not increased or even decreased by a small amount, ‘more communicable’ is still a very scary thing at this point in the pandemic, because it can result in faster spread and faster exponential growth.”