The independent academic news outlet The Conversation details the key role that next generation sequencing plays in the identification of variants of the novel coronavirus (COVID-19). A blanket term that applies to a broad spectrum of automated genetic sequencing techniques, next generation sequencing can determine the precise chemical sequence of both DNA and RNA strands.
As determined by James Watson, Francis Crick, and J. Rosalind Franklin in the early 1950s, the double helix structure of DNA consists of various combinations of the chemical bases adenine (A), thymine (T), cytosine (C), and guanine (G). Over the history of molecular genetic research, scientists have used a variety of constantly evolving techniques to detect the progressive order of these bonding bases.
When any living thing reproduces or replicates, it copies its entire genome (total DNA) to pass on at least some of this code to its offspring. Because this code, with its A’s, T’s, C’s, and G’s, determines all of the inherent biological traits of this offspring, its immense importance cannot be underestimated.
Over a series of new generations, small errors tend to arise during the DNA copying process. Otherwise known as mutations, these errors occur when one or more chemical base building blocks are traded, inserted, or deleted. In the case of the COVID-19 virus, these mutations can dramatically alter its ability to spread and the severity of its impact on the human body. This fact is even more alarming considering COVID-19’s exceptionally rapid rate of replication, which has the capacity to send the mutation process into overdrive.
Thankfully, the automated technologies that drive next generation sequencing can process incredibly high volumes of DNA very quickly. Evolving constantly since the 1990s, these technologies represent a giant leap forward from first-generation genetic sequencing technologies such as Sanger sequencing. What took Sanger sequencing weeks to accomplish, next generation sequencing can complete in a matter of hours.
Using Sanger sequencing, the scientists behind the historic Human Genome Project took 13 years to map the human genome in its entirety. Today, the Illumina NovaSeq next generation sequencing technology can map the combined nucleotide equivalent of 48 human genomes in only 3 days.
In light of its incredible speed and efficiency, next generation sequencing is a powerful tool in the fight against the novel coronavirus. Quick public health responses to COVID-19 outbreaks require an in-depth understanding of the ways in which the virus’s genetic makeup is changing over time. For this reason, researchers have been using next generation sequencing to track mutations in COVID-19 since the earliest days of the pandemic.
To date, scientists have sequenced millions of individual COVID-19 genomes and complied extensive records of these genomes in public repositories such as the National Center for Biotechnology Information and the Global Initiative on Sharing Avian Influenza Data. Consequently, next generation sequencing has been able to more effectively guide critical public health decisions as each new COVID-19 variant has materialized.
As just one key example, scientists detected more than 30 mutations in the Omicron COVID-19 variant spike protein, which enables the virus to bind to the cells of the human body. This allowed research teams to identify Omicron’s increased capacity to spread long before it began to infect large numbers of people. Guided by this information, public health officials were able to mount far more effective strategies to manage and contain this deadly new COVID-19 variant.
The timely detection of Omicron demonstrates just how important next generation sequencing data can be when it comes to saving lives around the world. And the world is a safer place as scientists continue to employ the technique to monitor future viral variants.
