WHAT IS A VARIANT?

WHAT EXACTLY IS A variant?

How do virus variants arise? And what can we do to protect ourselves from them? Experts explain the science behind the headlines.

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You have free access to 24-hour medical assistance and counselling telephonically by calling 0860 00 7325. THERE HAVE BEEN MANY ALARMING REPORTS about new variants of the novel coronavirus, SARS-CoV-2, which causes COVID-19. One of the variants, called Beta, was even discovered in our own backyard, in the Eastern Cape, in October 2020. But how and why do they occur?

Viruses are tiny molecular machines that invade other organisms’ cells, which they hijack to make copies of themselves. The copies then go on to infect other cells. This overwhelms your immune system and makes you feel ill. But every time a virus creates a copy of itself, that copy will be different in microscopic ways to its ‘parent’.

HOW A VARIANT WORKS

These tiny ‘errors’ in the genetic sequence of a virus, known as mutations, occur naturally and randomly. Most of the time they don’t affect the behaviour of the offspring virus. However, sometimes changes give the offspring an advantage over the parent virus. Here, the location of the

mutation matters, says Dr Mankgopo Kgatle, a medical virologist and Head of Basic and Translational Research at the Nuclear Medicine Research Infrastructure in Pretoria.

“With SARS-CoV-2, we have seen mutations to the spike protein – that’s the ‘key’ on the virus that allows the viral particles to enter our cells – which have made the virus more transmissible,” she says. That means it spreads more rapidly, resulting in more waves of infection and sickness, and more hospitalisations and deaths.

Variants don’t always cause problems. But when they do, scientists call them ‘variants of concern’. These may spread faster, cause more severe illness, or be better at evading immune defences than earlier versions of the virus, says Dr Marion Morkel, Chief Medical Officer at Sanlam.

Variants can arise anywhere, Dr Morkel says, but the likelihood that they

do can increase under certain conditions. For example, when the host stays infected for a long time, unable to clear the infection, that gives the virus a chance to multiply – and mutate – many times. This has the potential to create a virus variant with superpowers.

So how can we stop dangerous new variants from arising? The best way to do that is to slow the spread of the virus, says Dr Kgatle. Vaccines are an important part of that, she explains. But so are people continuing to wash their hands, wear masks and avoid crowded areas, regardless of whether they have been vaccinated or not, says Kgatle.

Variants don’t always cause problems. But when they do, scientists call them ‘variants of concern’.

1. When SARS-CoV-2 viruses enter our body, they hijack

our cell machinery

to make millions of copies of themselves. 2. These copies are never identical to their parents, but develop random

errors in their genetic

code known as mutations.

3. These mutations arise by accident, and most don’t affect the virus.

4. However, sometimes mutations happen that make the new virus ‘better’ at infecting us.

5. When the virus copies spread to other cells, and then to other people, mutations make them more successful at spreading.

6. They can even cause new waves of infection, as was seen with the Beta variant found in the Eastern Cape.

7. The only way to stop new variants forming is to stop the virus from spreading and making more copies of itself.

8. Vaccines can help with this, but so can handwashing, mask-wearing, and avoiding crowds.