Health professionals insert visitor information into laptops before administering doses of the Pfizer-BioNTech Covid-19 vaccine at Maternal Children’s Hospital in Belgrade, Serbia, on Sunday, January 10, 2021.
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Viruses mutate constantly, so it’s not surprising that the coronavirus that emerged in China in late 2019 has gone through several minor variations. But it has also undergone several major mutations and more significant variations are likely to emerge.
More recently, strains have emerged in South Africa and the UK that have raised concerns about the effectiveness of vaccines against coronavirus. A new strain in the U.S. is also suspected, with the White House coronavirus task force warning earlier this year that there could be a new, more communicable variant of the virus that has evolved in the U.S. and is driving the spread, according to a document. obtained by NBC News.
And on Sunday, Japan’s National Institute of Infectious Diseases said it had detected a new variant of the coronavirus in four travelers arriving from Brazil.
Essentially, scientists are concerned about any major changes in the virus’s so-called spike protein. This contains the receptor-binding domain and is used by the virus to enter cells in the body.
Thus, mutations can not only make the virus more transmissible, but also make vaccines less powerful and require them to be updated.
The ‘UK variant’
A new variant was reported by UK health officials to the World Health Organization on 14 December which is now formally known as “VOC 202012/01” (meaning “concern variant, year 2020, month 12, variant 01” ).
The variant was first detected in a patient in Kent, southeastern England, in September. Then it spread quickly to London. With infections increasing in both regions, initial analyzes suggested that it may be up to 70% more transmissible than the old variant that circulated in the country.
News of the new variant prompted many countries to ban flights from the UK in an attempt to keep the new lineage out, and prompted the country’s government to rule out a planned relaxation of social restrictions during Christmas. However, the mutation has caused a huge increase in infections, with the number of new daily cases reaching more than 50,000 since December 28.
WHO notes that “how and where SARS-CoV-2 COV 202012/01 originated is unclear”, although scientists are investigating whether the mutation appeared in patients with weaker immune systems who had long-term coronavirus infections, giving the virus the opportunity and time to evolve in a way that allows it to spread faster.
The ‘South Africa variant’
Following news from the UK, South African authorities announced on December 18 the detection of a mutation that was spreading rapidly in the Eastern Cape, Western Cape and KwaZulu-Natal. It has now become the dominant strain of coronavirus in the country.
South Africa called the variant “501Y.V2” because of the N501Y mutation found in the protein spike. This mutation, among others, has also been found in the new strain of the United Kingdom and, as such, is believed to be more transmissible in the same way.
The South African strain contains other mutations, and this has raised concerns that it could be more resistant to coronavirus vaccines. However, most scientists expect vaccines to work despite the mutation, and vaccines are regularly adapted to new strains of viruses, such as the common flu.
The ‘Danish mink variant’
Another variant of the coronavirus that appeared in Denmark last summer was linked to the country’s large agricultural mink sector. Since June, 214 human cases of Covid-19 have been identified in Denmark with variants associated with cultivated mink. Twelve of these cases were identified as having a single variant that was reported to WHO on 5 November.
The new strain was found in North Jutland, Denmark, and has been linked to infections among cultivated mink that were later transmitted to humans.
Minks are seen on a farm in Gjol, northern Denmark, on October 9, 2020.
HENNING BAGGER | Ritzau Scanpix | AFP via Getty Images
“The variant, known as the ‘Cluster 5’ variant by the Danish authorities, had a combination of mutations not previously seen,” noted the WHO. He added that these raised concerns that they could “result in reduced neutralization of the virus in humans, which could decrease the extent and duration of immune protection after natural infection or vaccination.”
Studies are underway to assess the effectiveness of treatment among humans with this variant. Fortunately, it does not seem to be transmissible, according to the European Center for Disease Prevention and Control and the WHO. Denmark took drastic measures, killing 17 million cultivated minks.
Early mutation in China
The WHO notes that a variant of the coronavirus appeared at the beginning of the pandemic (in fact, even before a global pandemic was declared in March 2020), noting that a new strain with a mutation known as “D614G” appeared in late January or early February 2020.
After several months, it became the dominant strain of the virus we know today, the WHO said. “Over a period of several months, the D614G mutation replaced the initial SARS-CoV-2 strain identified in China and in June 2020 it became the dominant form of the virus circulating globally.”
Studies in human respiratory cells and animal models have shown that, compared to the initial strain of the virus, the most recent strain increased its infectivity and transmission. However, the new variant was not seen as causing “more serious illnesses or altering the effectiveness of existing laboratory, therapeutic, vaccine or preventive public health measures”.
No blame game
Although the variants are sometimes dubbed the “UK strain” or “Denmark mutation”, experts say it is important to note that the origin of these viruses is difficult to prove and countries should not be “blamed” for different mutations.
Similarly, U.S. President Donald Trump has been criticized for calling Covid-19 “the virus in China” – the coronavirus may have appeared in China, but we still don’t know its origins and a team of WHO experts is traveling to China this week to investigate. For now, most scientists believe that the virus was transmitted to humans from an animal species, possibly from bats.
Many countries where variants have been discovered – including the United Kingdom, Denmark and South Africa – are known for their regular surveillance and sequencing of the virus’s genetic code and are therefore at the forefront of mutation discovery. WHO and other public agencies, such as the United States’ Centers for Disease Control and Prevention and the EU’s ECDC, are kept up to date by scientists from around the world as important variants emerge.