SAN DIEGO (KGTV) – Scientists this week in California discovered the first cases of the South African variant, a version of the coronavirus that seems elusive to current vaccines and the natural immunity of previous infections.
The South African variant shares a mutation with the British variant that scientists believe makes the virus stickier and more transferable to cells. The South African variant, officially known as B.1.351, has two other mutations in its spike proteins that scientists consider problematic.
The researchers pay close attention to the virus’ spike proteins as they enable the pathogen to attach to cells. Spike is also the protein that the current generation of COVID-19 vaccines are targeting.
All current vaccines train the immune system to build antibodies by introducing fake spike proteins. These harmless scammers look just like the prickly buttons on the surface of the actual coronavirus.
The South African variant, however, has tiny mutations in its tips that make it difficult for some antibodies to bind, based on previous research.
“The whole tip doesn’t change shape. What happens is a little button or a piece – we call it an epitope – to which certain antibodies bind so that they no longer bind, ”said virologist Dr. Doug Richman from UC San Diego.
A study by Moderna using blood samples found that the antibodies produced by the vaccine against the South African variant were six times less effective.
There have also been several confirmed cases of COVID survivors being re-infected with the variant. A vaccine study in South Africa found new infections in 2 percent of people infected with a previous version of the virus.
In general, second infections tend to be milder than the first, Richman noted.
He also stressed that the vaccines have shown promising results in their ability to prevent serious illnesses caused by the variant, even if they cannot completely prevent symptoms.
“What will happen is that someone who would have a life-threatening or hospital-required infection will have a milder infection,” he said.
The South African variant differs from the British variant, which has been found in around 1,000 people in the USA.
The British variant B.1.1.7 currently accounts for around 1 to 2 percent of infections in the USA, but is spreading rapidly. A study by Scripps Research estimates that it will double every 10 days and will be the dominant strain in this country by the end of March.
The two variants share a mutation that makes the virus stickier known as N501Y. This scientific abbreviation means that at the 501st amino acid position in the virus sequence an “N” (the abbreviation for asparagine) has been replaced by a “Y” (the abbreviation for tyrosine).
The South African variant, however, contains two other mutations, E484K and K417N, that appear to help her escape, said Scripps researcher Karthik Gangavarapu.
“These mutations together give the end result that it can escape immunity,” he said.
Gangavarapu is part of the laboratory that discovered the British variant in San Diego. So far, he has said that they had not discovered the South Africa variant in their samples.