SARS-CoV-2 Variants, Explained

As new SARS-CoV-2 variants emerge, tried-and-tested solutions could be the key to stamping out COVID-19.

AsianScientist (May. 24, 2021) – This time last year, the world was markedly different. Caught in the throes of COVID-19, countries like Singapore and the US implemented unprecedented lockdowns, while in places like Italy, medical workers waged a spirited fight against a mounting death toll.

Since then, the situation has considerably eased in most parts—largely due to the availability of vaccines, with over 1.63 billion doses already administered. But despite the lightning-fast development of COVID-19 vaccines, the emergence of SARS-CoV-2 variants may derail our progress against the pandemic if left unchecked. In this explainer, Asian Scientist Magazine reviews some of the variants currently in circulation—examining their origins and mapping their implications for public health.

What’s in a variant?

In the weird world of viruses, mutations are nothing new. Consider the influenza viruses that cause our regular flu outbreaks. As these viruses mutate significantly on a yearly basis, getting the latest flu shot has become an annual tradition for many.

In fact, compared to influenza and other viruses like HIV, the coronavirus seems almost sluggish. Its nearly 30,000-base genome accumulates only two single-letter mutations per month, a rate around half that of influenza and one-quarter of HIV.

“Viruses like SARS-CoV-2 mutate constantly as part of its natural evolution,” explained Dr. Cynthia Saloma, executive director of the Philippine Genome Center. Earlier this year, Saloma and her team were the first to discover a new variant in the Philippines, thanks to their surveillance efforts. “SARS-CoV-2 is a single stranded RNA virus and during its replication process, errors occur during the copying of its genome,” she added.

These errors—otherwise known as mutations—could be as tiny as a single letter change or as major as the deletion of an entire fragment. According to Saloma, though these mutations may seem like cause for alarm, they’re typically inconsequential. Occasionally, however, a mutation may enhance the virus’ ability to infect, cause disease or evade the immune system.

Given the uneven pace of the global vaccine rollout, it’s likely that we’ll see more of these mutations to come. As long as the coronavirus remains widely circulated in a population, each new infection will give SARS-CoV-2 a fresh chance to mutate—making vaccination a race against time.

A molecular biologist by training, Kami Navarro left the sterile walls of the laboratory to pursue a Master of Science Communication from the Australian National University. Kami is the former science editor at Asian Scientist Magazine.

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