Around the same time that the first vaccines against COVID-19 were approved and acquired in December 2020, health officials in the UK announced the discovery of a new strain of the virus.
Initial reports based on limited early evidence suggested it could be more contagious. A few days later, the discovery of another variant of the coronavirus was announced in South Africa, which at the time registered more than 15,000 cases of COVID-19 infections daily, the highest number in Africa.
And in January another variant was discovered in Brazil, originating from the northern state of Amazonas.
According to Dr. Deepti Gurdasani, a clinical epidemiologist and associate professor at Queen Mary University of London, a variant called D641G was developed in the Chinese city of Wuhan in February-March last year in the Chinese city of Wuhan, the site of the first known case of COVID 19 was confirmed. in December 2019.
“That variant was associated with an increase of about 20-30 percent in transferability, which quickly became the dominant variant in the world,” Gurdasani told Al Jazeera.
“This highlights the potential of this virus to adapt.”
But let’s start at the beginning.
What is a variant?
Variants are mutations of a virus. All viruses mutate when they copy themselves to spread and thrive. Most mutations are insignificant, some can actually harm the virus, and others can produce a variant that makes it more transmissible.
To break it down further, a mutation is a change in the genetic material of the virus – or so-called ribonucleic acid (RNA).
A virus spreads in the body by attaching itself to a cell and then entering it. They then make copies of their RNA, which allows them to multiply. When there is a copying error, the RNA changes and scientists call that a mutation.
Brooke Nichols, an assistant professor at the Boston University School of Public Health, said that mutations are much more common in RNA viruses because the RNA has’ no ‘proofreading’ capacity and as such, the mistakes made during viral replication cannot correct ‘ .
“This can become problematic when the virus then selects for mutations that allow the virus to replicate more efficiently,” Nichols told Al Jazeera.
“For example, if a person has been previously infected, the virus can select for mutations that can bypass that previous immunity, or select for mutations that allow better virus transmission.”
How do variants affect people?
The coronavirus disease has undergone several mutations since the start of the pandemic.
All three variants detected in the UK, South Africa and Brazil have undergone changes in their spike protein. This is the part of the virus that attaches to human cells and makes them better at infecting and spreading cells.
While scientists agree that the mutations in the three variants make the coronavirus more contagious, there is no evidence that these actually worsen the disease or cause more death.
“The variants do not appear to make coronavirus disease more deadly,” Nichols said. “However, the variants make the virus more transmissible. This could mean that more people could become infected more quickly – and thus still overload healthcare systems. “
B.1.1.7
On December 14, British health officials reported a new variant to the World Health Organization (WHO).
The variant, called B117, was first discovered in Kent, southeast of England, in September. In December, the strain was responsible for 60 percent of new COVID-19 cases in the UK, becoming the most common version of the coronavirus in the country.
While preliminary evidence suggests the variant could be up to 30 percent more deadly than the previous dominant species, experts say the data is limited and there still isn’t much information to determine how contagious it is.
It was initially reported that the variant could be up to 70 percent more transmittable, but according to the latest Public Health England study, it is between 30 and 50 percent.
Early research seems to show that vaccines are effective against this variant. Last week, the studies with Novavax and Johnson & Johnson showed that they were 86 percent and 66 percent effective, respectively.
In late January, scientists said trials showed the Moderna vaccine appeared to work against the variant.
The British species has been detected in more than 50 other countries, including China, India and the United States
Recently, experts said the variant has a mutation present in the South African variant – the E484K, which is thought to help the virus evade parts of the immune system and antibodies.
B1351
Medical staff treat a COVID-19 patient in a special ward of Arwyp Medical Center as South Africa has hit a million infections milestone [File: Shafiek Tassiem/Reuters]
Days after the new variant was announced in the UK, South African authorities said on December 18 that a new variant was rapidly spreading in Eastern Cape, Western Cape and KwaZulu-Natal.
The B1351 variant first appeared in the country in October and has since become South Africa’s dominant coronavirus strain.
The variant has also been found in 32 other countries, including the UK.
Research showed that the variant also has the E484K mutation, as well as the N501Y mutation – making it appear to be more transmissible.
Recent studies have shown that some vaccines are less effective against this variant than others.
The vaccine developed by AstraZeneca and the University of Oxford appeared to offer only limited protection, the British-Swedish drugmaker said.
Novavax said preliminary data from clinical trials showed the vaccine was 60 percent effective. Johnson & Johnson said clinical studies conducted in South Africa have shown the vaccine to be 57 percent effective in stopping moderate to severe cases of COVID-19. Both vaccines have yet to be approved by regulators.
On Jan. 25, Moderna, whose vaccine is being rolled out around the world, said it was developing a booster shot after discovering the vaccine was less effective against the South African variant. It is currently being tested whether a third booster shot could be useful.
B11248
The variant of the coronavirus detected in Japan from the Brazilian state of Amazonas is already dominant in the capital, Manaus, reinforcing early suspicions that it may be more contagious. [Marcio James/AFP]
A separate new variant was discovered in mid-January among passengers arriving in Japan from Brazil.
The origin of the B11248 variant can be traced back to the northern Brazilian state of Amazonas, where it was first discovered in December in the capital, Manaus.
It also has the E484K mutation.
“What we know has independent and shared mutations with both the British and South African variants,” said Dr. Deepti Gurdasani.
This particular variant is of concern “because it has been associated in the laboratory with significantly reduced neutralization of antibodies against previous variants,” she continued.
During the first wave of the virus in Brazil last year, 76 percent of people in Manaus were exposed to it.
“But we are still seeing massive waves of infections and it is very unclear at this point why that is,” Gurdasani said. “We may be dealing with a new variant, which makes it more transferable, which increases the herd’s immunity threshold. But it may also be that this variant, at least for some people, escapes the immune response to the previous variant. “
The variant was present in 51 percent of samples taken from coronavirus patients in December, he said. In mid-January, it appeared in 91 percent of the samples.
Scientists don’t understand why the variant has spread so explosively in Brazil and why it contains a particularly dangerous series of mutations.
Will vaccines work on the new strains?
Mutations help the virus evade antibodies or escape recognition by them.
However, vaccines train the immune system to attack different parts of the virus. That is, the vaccines’ antibodies target many parts of the spike protein, so although part of the spike is mutated, the vaccines should still provide some level of protection.
On Jan. 27, Pfizer said its vaccine was slightly less effective against the British and South African variants.
Even in the worst-case scenario, vaccines that use mRNA technology, such as the Pfizer-BioNTech and Moderna vaccines, can be redesigned and modified to be a better match in a matter of weeks or months if needed, say medical experts.