December 31, 2020, local time, the WHO officially reported on the main variants of the novel coronavirus since its emergence, including four variants.
From late January to early February 2020, the novel coronavirus showed a mutation of D614G, which gradually replaced the initially discovered strain.
By June 2020, the variant became the dominant type of COVID-19 that spreads worldwide. Studies have shown that the variant is more infectious and transmittably than the initial strain, but does not cause more serious disease and does not affect the effectiveness of existing diagnostics, treatments, vaccines and public health measures.
In August and September 2020, a variant of COVID-19 associated with mink was discovered in Denmark, named “Cluster 5” by the Danish authorities, with a mutation that had not been previously observed.
According to preliminary research conducted in Denmark, it is worrying that this variant may reduce the scope and duration of immune protection caused by natural infection or vaccination, and the assessment is still under way. At present, only 12 cases of human infection with this variant have been found in Denmark in September, which does not seem to have spread widely.
On 14 December 2020, the United Kingdom reported to WHO a variant of the novel coronavirus, named VOC 202012/01, which first appeared in southeastern England.
Preliminary epidemiological studies show that the variant has stronger transmission power, but the severity of the disease (estimated by hospitalization time and 28 days of mortality) and reinfection have not changed, and most diagnostic tools are not affected. As of December 30, 31 other countries and territories in five of the six WHO regions have found this variant.
On 18 December 2020, a variant of COVID-19 was detected in South Africa, with a mutation of N501Y, which South Africa named 501Y.V2 variant, which is spreading rapidly in three South African provinces.
Although the mutant COVID-19 previously discovered in the UK also has N501Y mutation, the analysis shows that it is a different variant from the mutant novel coronavirus found in South Africa.
In the week following 16 November, South Africa’s health department found in routine gene sequencing that this variant has largely replaced other COVID-19 that have spread in the Eastern Cape, Western Cape and KwaZulu-Natal provinces. Preliminary studies suggest that the variant is associated with higher viral loads and may increase the contagion, but there is no evidence that it causes more serious diseases.
Further investigation is needed to understand the impact of this variant on virus transmission, diagnosis, vaccines, etc. As of December 30, four countries outside South Africa had discovered the variant.
The WHO said that countries affected by mutant COVID-19 are conducting epidemiological and virological investigations to understand its prevalence, and genetic data on mutant COVID-19 found in the United Kingdom and South Africa have been shared.
WHO also pointed out that all viruses, including COVID-19, change over time, and most mutations do not increase the infectivity of the virus, and sometimes even limit its transmission. As the frequency of human and animal infections increases, the possibility of viral mutation also increases.
WHO also stressed that although preliminary assessments show that the mutant novel coronavirus found in the United Kingdom and South Africa will not increase the severity of the disease, it will lead to higher incidence and more hospitalizations and deaths, so stricter public health measures are needed to control the spread of these mutant viruses.
WHO also recommends that countries increase routine genetic sequencing of COVID-19 to better understand the spread of the virus and monitor variants.