Viral genome sequence data to diffuse a second wave

June 10, 2020 0 By S Harachand

Even as countries around the world expect a second wave of COVID-19 infections with the easing of lockdown measures, researchers are planning to exploit the pathogen’s genome sequencing information to avert such a possibility.

The first whole-genome sequence of SARS-CoV-2 went online in January. Currently, data comprising around 32,000 viral genomes from around the world is available in the public domain. This vast database of viral gene pool helps researchers to trace the origin of COVID-19 outbreaks in their countries. 

The genomes of the virus will have mutated in the past two months just enough to tell whether they come from outside the state. This will help identify the exact source of exposure to the virus, particularly when regional transport is reopened.

Several distinct lineages of the circulating SARS-CoV-2 have started evolving all over the world. Data from their genomes will now aid researchers instantly rule out possible lines of transmission if two sequences don’t match, or link together cases that do, according to a report published in Nature, recently.

The sequencing data can also be effectively utilised to monitor community transmission in comparison with various suppression measures such as contact tracing. 

Evidence suggests that outbreaks tend to be shorter and smaller when genomics is used to aid contact tracing.

Some countries have already embarked on sequencing viral genomes in their population. 

New Zealand, which is hoping to sequence viral genomes from at least 70% of the infected people, have already completed the sequencing of 25% of reported cases. 

The UK, US and Australia are also using sequencing data to track new infections post lockdown.

But one of the major limitations of this method is that people who experience asymptomatic infections are unlikely to get tested.

Also, the use of genomic analysis as an aid to contact tracing is currently restricted to high-income countries.