Since the novel coronavirus first burst on to the global scene, only to cause a pandemic eventually, the virus has undergone several mutations from its original self. These mutations have been documented by scientists from across the globe but only a few are being closely monitored.
These strains of the coronavirus are mostly identified with the country of their origin and hence include the strain from the UK, South Africa, Nigeria and the most recent one as the strain in Japan.
Upon analysis, scientists have concluded that these strains differ in their transmissibility rate as well as potency to cause an illness. Although the strains are not known to be any more lethal than the prevalent Covid-19 variant, they have been found to transmit from an infected to a healthy person more easily.
This has in turn caused a spike in infections across countries bringing in a second or a third wave of Covid-19 infections in some cases. As a result, the healthcare facilities have been overburdened and the Covid-19 has claimed more deaths than ever before, as was recently seen in the UK.
Health experts, hence, are keeping a close eye on these mutated strains of the coronavirus and their potential to aggravate the pandemic. Here, we try to have a similar look at these strains of the coronavirus and how they have spread across different countries over time.
The UK Covid-19 strain was first reported by the UK authorities to the World Health Organisation on December 14. The first case of the variant was recorded sometime in September. By November around a quarter of cases in London were the new variant, reports BBC.
This proportion reached nearly two-thirds of cases being those of the new variant by mid-December. As of today, the UK strain of the virus has been reported in thirty one other countries, including China, India, and the United States.
One of the important alterations in the mutated virus is believed to be that of its spike protein, better enabling it to infect the host cells. The virus strain has hence been linked with more transmissibility and has hence spiked up the infection count since coming into the picture.
The first cases of the UK strain in India were detected on December 29 when six passengers returning from Britain were tested positive for the new coronavirus strain. Since then, 96 people have been confirmed to be infected with the mutated strain of the virus.
National authorities in South Africa announced the detection of a new variant of SARS-CoV-2 to the WHO on December 18. The variant was found to be rapidly spreading in three provinces of South Africa at the time.
Following the detection, South African health authorities started routine sequencing of the new coronavirus variant. It was found that this new SARS-CoV-2 variant had largely replaced other SARS-CoV-2 viruses circulating in the Eastern Cape, Western Cape, and KwaZulu-Natal provinces.
The mutation has been responsible for a surge in Covid-19 cases in South Africa, which are now recording all time high numbers on a daily basis. The mutation even managed to spread to other countries through travel. South Africa is facing travel bans from several countries.
As of January 11, the coronavirus variant from South Africa has been reported from sixteen other countries. The total number of infections, however, remains limited to somewhere in the 20s.
Other than the coronavirus strains found in the UK and South Africa, African authorities announced the detection of a new Covid-19 strain in Nigeria on December 24. The authorities called for more investigation on the variant at the time.
"It's a separate lineage from the UK and the South African lineages," John Nkengasong, director of the Africa Centres for Disease Control and Prevention (CDC) told an online news conference from Addis Ababa as quoted in a report by Reuters. "The one we are seeing in Nigeria, and this is based on very limited data yet, has the 501 mutation," Nkengasong added
The strain is not yet considered to be more infectious or lethal than its counterparts. Nkengasong further confirmed that the Nigeria CDC and the African Centre of Excellence for Genomics of Infectious Diseases in Nigeria will study more samples of the strain going forward. As of now, no other country has reported the Nigeria strain of the disease.
The latest in line of mutated coronavirus strains, the new strain was detected by Japan¡¯s NIID on January 6. The new mutant strain was found in four passengers arriving in the country from Brazil¡¯s Amazonas state on January 2. All travellers are now in quarantine at Tokyo's airport.
As per the NIID, the new strain has 12 mutations in the spike protein. It is, however, yet to be seen if the newfound strain is more infectious than the rest. Japan says that it is now conducting more studies on the new coronavirus strain to monitor the effect of Covid-19 vaccines against the strain.