Since the 2019 New Crown outbreak, New Crown virus has achieved a global pandemic and undergone multiple mutations. As of August, it is reported that at least 11+4=15 mutant virus strains of interest, concern and need for attention have been identified globally.

The WHO classifies newly crowned mutant strains into two categories according to their risk level: VOC (variant of concern) and VOI (variant of interest). The former has caused many and widespread cases worldwide and has data confirming its ability to spread, be highly virulent, or lead to reduced effectiveness of vaccines and clinical treatments; the latter has confirmed cases of community transmission worldwide or has been identified in multiple countries, but has not yet developed large-scale transmission.

Currently, VOC is the mutant strain that has the greatest impact on the epidemic and also the greatest global threat, including: Alpha, Beta, Gamma and Delta. The strain that is currently causing the outbreak to rebound in many parts of the country is the Delta variant, which is the most contagious of all the strains of the virus found so far, and is 50% more contagious than the Alpha variant. The WHO's weekly epidemiological report released on Tuesday (5) shows that 192 countries and territories now have people infected with the Delta variant.

So why are there so many mutations of the new coronavirus?

First, let's be clear that the new coronavirus is a single-stranded RNA virus, a strictly parasitic organism that can only replicate within living cells. In fact, mutation is a normal part of viral self-replication, and viruses do not always make exact copies of their genetic material, but often make errors that lead to mutations. The unstable structure of the single-stranded RNA of neo-coronaviruses makes them more susceptible to mutations during replication or in response to the external environment.

The constant mutation of neo-coronaviruses poses a very big challenge to epidemic prevention and control, especially for rapid means of nucleic acid detection of neo-coronaviruses. Although some experts now say that the Delta mutant strain has stabilized, it is still unknown whether the virus will develop to new levels.

The WHO says that while the New Coronavirus continues to mutate, "public health and social measures" are still key to containing the spread of the epidemic and rapid nucleic acid testing for New Coronavirus remains the "gold standard" for diagnosing New Coronavirus infections.

The Nucleic Acid Rapid Test (NAKT) is a test that detects specific nucleic acid fragments on the NSC virus. The fluorescence PCR method is used to amplify the nucleic acid sequence exponentially by PCR, and the more target genes are amplified, the stronger the accumulated fluorescence signal will be. In contrast, in samples without virus, no target gene amplification is present and therefore no fluorescence signal enhancement is detected.

The conventional amplification reaction time may take 2-3 hours, and with the continuous improvement of technology, the amplification time has now been substantially improved.