Is the coronavirus mutating, and what does this mean for the future?

22 May 2020 - 12:41
By Sanet Oberholzer
Image: 123RF/Kateryna Kon

The strains from the original Covid-19 outbreak in China have been compared to new outbreaks, and there are signs the virus could be changing.

According to Bloomberg, Chinese doctors are observing a difference in how the virus is manifesting in new patients infected with the coronavirus.

Dr Qiu Haibo, a Chinese expert in critical care medicine, told Chinese state television that newly infected patients in the northern provinces of Heilongjiang and Jilin appear to take longer to test positive for the virus, take longer to exhibit symptoms, and carry the virus for longer when compared to patients who were infected in the original outbreak in Wuhan.

Qiu said this delay in identifying new cases is making it difficult to catch new cases and limit the spread. The biggest question is: what does this mean for the fight against Covid-19?

Dr Jinal Bhiman, a principal medical scientist at the National Institute for Communicable Diseases, said the Covid-19 virus is not unusual in its ability to mutate, as all viruses do so.

“However, perhaps luckily for us, Sars-CoV-2 mutates relatively slowly, and currently, these viruses circulating globally have not diversified enough to form distinct strains,” she said.

Recently, an unpublished and unreviewed preprint study from researchers at the Los Alamos National Laboratory in the US resulted in a media frenzy by claiming that a mutation has increased the transmissibility of the virus. Bhiman said this is a serious overstatement as the evidence is just not strong enough to support such claims.

Dr Susan Louw, a Dettol key opinion leader and haematopathologist at the National Health Laboratory Service in SA, said mutations in viruses are very random, and the frequency of mutations varies across viruses.

“For example, the flu virus is very prone to mutate all the time. Every season the virus looks slightly different compared to the previous season,” she said. “What we have observed with the Covid virus is that it does not mutate or change very rapidly.”

Not all mutations are beneficial to a virus. Some mutations may make the virus less virulent, or less capable of infecting the next host, or may even make the virus less capable of inducing serious disease in the next host. However, mutations can also have the opposite effect, making the virus more aggressive. At this stage, it is still unclear what these mutations will mean for Covid-19.

“We don’t really know but it seems as though the Covid virus does not mutate as rapidly, for example, as the ordinary flu virus does. It also seems as though the mutations do not lend a lot of additional virulence to the virus,” said Louw.

While it is still uncertain when a vaccine will be found, the next question around mutations will pertain to whether — once we’ve obtained a vaccine — it will still be able to offer protection if it was manufactured with a current strain of the virus.

“That question still remains to be answered,” said Louw. “We’re not 100% sure, but it seems the mutation rate in the Covid virus is such that we will still be protected although the vaccine [may have been] manufactured on the first sequence.”

It is unclear whether cases similar to those in China are being observed in South Africa.

At this stage, South Africa is in a much more primitive phase of the virus, and the number one focus is rolling out accurate and reliable testing throughout the country.

Louw said samples are being collected and stored, and eventually SA will study the distribution and patterns of the virus on home shores.