Almost at the same time, the first vaccines against COVID-19 were being approved and purchased in December 2020, health authorities in the United Kingdom announced the discovery of a new strain of the virus.
Initial reports based on limited initial evidence suggested that it could be more infectious. A few days later, the discovery of another variant of the coronavirus was announced in South Africa, which at the time recorded more than 15,000 cases of COVID-19 infections daily, the largest number in Africa.
And in January another variant was detected in Brazil, originating in the state of Amazonas.
According to Dr. Deepti Gurdasani, clinical epidemiologist and senior professor at Queen Mary University of London, a variant called D641G developed in February-March last year in the Chinese city of Wuhan, where the first known case of COVID- was confirmed. 19 in December 2019.
“This variant was associated with an increase of about 20-30 percent in transmissibility, 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?
The variants are mutations of a virus. All viruses mutate when they copy to spread and thrive. Most mutations are insignificant, some can actually harm the virus and others can produce a variant that will make it more transmissible.
To further decompose, a mutation is a change in the virus’s genetic material – or what is called ribonucleic acid (RNA).
A virus spreads within the body by attaching itself to a cell and then entering it. Then they make copies of their RNA, which helps them to proliferate. If there is a copy error, the RNA will be changed and this is what scientists call a mutation.
Brooke Nichols, assistant professor at the Boston University School of Public Health, said that mutations occur much more frequently with RNA viruses because RNA “lacks the ability to ‘revise’ and, as such, cannot correct the mistakes made during viral replication “.
“This can become problematic when the virus then selects the 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 mutations that can escape previous immunity or select mutations that allow the virus to be more transmissible.”
How do variants affect humans?
Coronavirus disease has undergone several mutations since the pandemic began.
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 binds to human cells and makes it better for infecting cells and spreading.
Although scientists agree that the mutations found in the three variants make the coronavirus more infectious, there is no evidence that it actually worsens the disease or is more likely to cause death.
“The variants don’t seem to make coronavirus disease more deadly,” said Nichols. “The variants, however, make the virus more transmissible. This could mean that more people can be infected more quickly – and therefore still overburden health systems. ”
B.1.1.7
On December 14, UK health authorities reported a new variant to the World Health Organization (WHO).
The variant, called B117, was first detected in September in Kent, southeastern England. In December, the strain accounted for 60 percent of new cases of COVID-19 in the United Kingdom, making it the most common version of coronavirus in the country.
Although preliminary evidence suggests that the variant may be up to 30 percent more deadly than the previous dominant strain, experts say the data is limited and there is still little information to determine how infectious it is.
It was initially reported that the variant could be up to 70 percent more transmissible, but the latest Public Health England survey indicates between 30-50 percent.
Initial research appears to show that vaccines are effective against this variant. Last week, Novavax and Johnson & Johnson tests showed that they were 86% and 66% effective, respectively.
In late January, scientists said tests showed that the Modern vaccine appeared to work against the variant.
The UK strain has been detected in more than 50 other countries, including China, India and the United States
Recently, experts said the variant has a mutation that is present in the South African variant – E484K, which helps the virus escape parts of the immune system and antibodies.
B1351
A medical team sees a COVID-19 patient in a special ward at Arwyp Medical Center when South Africa has reached the million infection mark [File: Shafiek Tassiem/Reuters]
Days after the new variant was announced in the UK, South African officials said on December 18 that a new variant was spreading rapidly across the Eastern Cape, Western Cape and KwaZulu-Natal.
The B1351 variant first appeared in the country in October and has since become the dominant strain of coronavirus in South Africa.
The variant was also found in 32 other countries, including the United Kingdom.
Research has shown that the variant also has the E484K mutation, as well as the N501Y mutation – which appears to make it more transmissible.
Recent trials 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 limited protection, said the Swedish-British pharmacist.
Novavax said preliminary clinical trial data showed its vaccine was 60 percent effective. Johnson & Johnson said that clinical trials conducted in South Africa have shown that its vaccine is 57 percent effective in preventing moderate to severe cases of COVID-19. Both vaccines have not yet been approved by regulators.
On January 25, Moderna, whose vaccine is being launched worldwide, said it was developing a booster injection after it found that its vaccine was less effective against the South African variant. It is currently testing whether a third booster injection can be beneficial.
B11248
The coronavirus variant detected in Japan from the Brazilian state of Amazonas is already dominant in its capital Manaus, reinforcing initial suspicions that it may be more contagious [Marcio James/AFP]
In mid-January, a new separate variant was discovered in passengers arriving in Japan from Brazil.
The origins of the B11248 variant date back to the state of Amazonas, in northern Brazil, where it was first detected in its capital, Manaus, in December.
It also has the E484K mutation.
“What we know has mutations that are independent and shared with the UK and South Africa variant,” said Dr. Deepti Gurdasani.
This particular variant is of concern “because in the laboratory it has been associated with a significant reduction in the neutralization of antibodies targeting previous variants”, she continued.
During the first wave of the virus in Brazil last year, 76% of people in Manaus were exposed to it.
“But we are still seeing huge waves of infections and it is not very clear why this is happening at the moment,” said Gurdasani. “It may be because we are dealing with a new variant, which is more transmissible, which increases the herd’s immunity limit. But it may also be that this variant escapes, at least for some people, the immune response to the previous variant. “
The variant was present in 51 percent of samples taken from patients with coronavirus in December, he said. In mid-January, it appeared in 91 percent of the samples.
Scientists do not understand why the variant spread so explosively in Brazil and why it carries a particularly dangerous set of mutations.
Will vaccines work on new strains?
Mutations help the virus to avoid antibodies or escape recognition by them.
However, vaccines train the immune system to attack several different parts of the virus. That is, vaccine antibodies target many parts of the peak protein, so even if part of the peak has mutated, vaccines must still offer a degree of protection.
On January 27, Pfizer said its vaccine was slightly less effective against UK and South Africa variants.
Even in the worst case scenario, vaccines that use mRNA technology, such as the Pfizer-BioNTech and Moderna vaccines, can be redesigned and adjusted to suit better in a matter of weeks or months if necessary, say medical experts.