New Coronavirus Variant Strain 501Y-V2 of South Africa
On December 18th, 2020, South Africa detected a 501Y-V2 mutant of the new coronavirus. Now the South African mutant has spread to more than 20 countries. Experiments have shown that above the New Corona-virus Mutants may carry other New Coronavirus variants of K417N/T, E484K and N501Y mutations that can reduce the neutralizing ability of the vaccine-induced plasma neutralizing antibodies. However, compared with the reference genome Wuh01 (sequence number MN908947), the 501Y.V2 of South African mutant genome sequence has 23 nucleotide variants. It has the same N501Y mutation as the Britain mutant B.1.1.7 sub-type, but still contains mutations at two key sites E484K and K417N of S protein that have potentially important effects on the ability of the virus to infect.
The New Coronavirus is a Single-stranded RNA Virus ,which Genome mutations are more frequent . Single-target detection can easily lead to missed detection of samples with low viral load and mutated virus strains. The rate of re-examination in the single positive in the target detection, can reach more than 10%, which may increase the workload and prolong the diagnosis time. Multi-target detection and mutual verification of the results of each target can increase the detection rate and facilitate early diagnosis.
Figure 1. Schematic diagram of the New Coronavirus infection mechanism
New Coronavirus Mutant B.1.1.7 of Britain
On December 26th, 2020, the first scientific paper of the B.1.1.7 Strain was published online. The Institute of Hygiene University of London UK and Tropical Diseases, confirmed that the B.1.1.7 Strain is more capable of spreading than other strains,which was more than 56% (95% CI 50-74%). Because this new mutant strain has more obvious transmission power, it has become more difficult to control COVID-19. The next day, the University of Birmingham in the United Kingdom uploaded an article on MedRxiv. The study found that the number of ORF1ab and N virus gene copies in patients infected with the B.1.1.7 mutant strain (S-gene dropout) was significantly increased; this phenomenon was monitored in the population. This article points out that patients infected with the mutant B.1.1.7 of Britain have a significantly higher viral load, so this mutant may also be more pathogenic.
Figure 2. The genome mutation sequence contained in the coronavirus mutant strain B.1.1.7 of Britain
Figure 3. N501Y mutation occured in both the Britain and South African Variants
Detection Kit of New Coronavirus Variants
Chuangkun Biotech Inc. has successfully developed a detection kit for B.1.1.7 and 501Y-V2 new coronavirus variants.
Advantages of this product: high sensitivity，simultaneous detection of 4 targets, covering the main mutation sites of B.1.1.7 mutant strain and 501Y.V2 South African mutant strain. This kit can simultaneous detect the N501Y, HV69-70del, E484K mutation sites and the new coronavirus S gene ; Fast test: it only takes 1 hour 30 minutes from sample collection to result.
Figure 4. Detection of COVID-19 Britain Variant Amplification Curve
Figure 5. Detection of COVID-19 South African Variant Amplification Curve
Figure 6. Wild-type of New coronavirus amplification curve
It is not clear how these mutations accumulate new long-term impact of the pandemic COVID-19 right. But this reminds us that these mutations may affect the effectiveness of natural immunity and immunity brought about by vaccination. It also reminds us that we need to continuously monitor the new coronavirus for a long time and update the COVID-19 vaccine to deal with the evolution of the new coronavirus.
Post time: Mar-12-2021