How dangerous are the new COVID-19 variants?

VACCINATION programmes around the world have been shown to be reducing COVID-19 transmission rates and hospital admissions. But news of COVID variants emerging — and spreading fast — is still a concern. Viruses mutate; this is to be expected. And, as the coronavirus spreads and infects more people, it will be given more opportunity to do so, particularly in countries that have been slow to lock down, enforce social distancing or close borders.

Mutations are random changes in the DNA of the virus that can alter its shape and the way it behaves. When a virus infects a human cell, its main job is to replicate and then spread.

The virus instructs the infected cell to start making more copies of itself that then go on to infect other cells and are eventually coughed, sneezed or breathed out, enabling them to infect other people.

Replication of the virus occurs at a relatively quick rate, however, which means errors can occur. Most of these errors are either harmful to the virus or have no effect, but as time goes on, the chances of an “advantageous error” — one that might make the original virus more powerful or infectious — occurring increase.

Here are the new variants the experts are keeping an eye on.

Brazil variant

Something terrible is happening in Brazil. The country, which suffered horrific losses during the painful first wave of COVID-19, now finds itself entangled in an even worse second wave. After the US, Brazil (population 213 million) has one of the worst COVID-19 death tolls in the world, with more than 11 million people testing positive and more than 270 000 dead.

Brazil’s leader, President Jair Bolsanaro, appears to have his head buried firmly in the sand as, in the past, the dismissed COVID-19 as a “little flu”. He has also repeatedly appeared in public without a face mask.

Recently he went to the midwestern state of Goiás, where nearly 9 000 people have died, and told people to “stop whining” about the coronavirus outbreak, a move that was widely condemned by other countries.

Furthermore, the rollout of vaccines in the country has been beset by supply problems and bottlenecks in the delivery process, as well as by false rumours such as one claiming the vaccine will turn people into animals.

To make matters worse, a new variant — known as the P1 variant — has now emerged. It was first identified in the Amazonian city of Manaus in December and is thought to be more infectious than the original virus, enabling it to become the dominant strain.

There is no evidence yet that this variant will make you more unwell, but as the virus is likely to infect more people this, inevitably, will result in more deaths. More than 2 000 deaths a day are already being recorded in Brazil, largely as a result of this new strain.

It is spreading fast. Since December, the World Health Organisation (WHO) has identified it in other countries, including Canada, the United States, the United Kingdom, France, Germany, Spain, Japan, Mexico, India, Italy and the Republic of Korea.

The new variant has overwhelmed hospitals in Brazil. Within weeks of identifying the new variant, Manaus saw cases begin to surge exponentially, including in people who had previously been infected by the original virus. So huge were the numbers of people becoming sick that the city ran out of oxygen, leaving doctors with agonising decisions to make over who to give what oxygen they had left to and patients dying of asphyxiation.

The P1 variant has been caused by a number of mutations, but three, in particular, are of concern to scientists.

The first is the E484K mutation, which has also been identified in the South African variant. It is being called an “escape” mutation as it changes parts of the spike protein of the virus that our immune systems rely on to recognise and initiate our immune response.

These changes may mean it can evade an immune response triggered by the vaccine or previous infection. More research is needed to fully understand this. The spike protein lies on the outer surface of the virus. When the virus enters a human host, it has to get inside cells to infect them. It does this by connecting its spike protein to receptors on the outer surface of human cells, called ACE2 receptors.

The E484k mutation has changed the spike protein of the original virus so that it binds more readily and forms a stronger connection to the host cells, making it more infectious. The same mutation also means the virus can evade the neutralising antibodies that a previous coronavirus infection has created more effectively. This may explain some of the reinfections in Manaus.

The second is the N501Y mutation, which is also present in the UK variant. This mutation also affects the spike protein of the coronavirus, but specifically its “receptor-binding domain”. This is the part of the spike protein which makes contact with human cells, clasps onto them and then allows the virus to enter.

Not only does this mutation make the virus bind more tightly to the human cells, but it also makes it more likely to stay bound to them, thus increasing the likelihood of infection. This mutation has allowed the UK variant to become the dominant strain in the UK and is most likely what helped the Brazil variant become dominant in Manaus.

According to information from the UK government, this mutation can make the virus up to 50 percent more infectious than the original virus.

The third is the K417T mutation, which is not as well understood as the other two. It also occurs in the receptor-binding domain of the spike protein and may make it easier for the virus to bind to human cells, increasing its infectivity. More research is needed on this mutation, but there is a school of thought that suggests this, combined with the N501Y mutation, will increase the binding capacity of the virus to human cells significantly, making the Brazil variant especially dangerous.

Scientists are working hard to find out if the current approved vaccines will be effective against this last mutation. So far, it has been shown that all the vaccines offer some level of protection against serious disease but this protection is lower when compared to variants without this mutation. Thankfully, the vaccine manufacturers say that if this variant becomes the dominant strain of the virus generally, then their vaccines can be adjusted quickly to accommodate this. The time it takes for these adjustments to be made will vary from vaccine to vaccine.

The Pfizer and Moderna vaccines, which use messenger RNA technology, can be done more quickly — within six weeks according to Pfizer-BioNTech. The Oxford-AstraZeneca vaccine, which uses DNA technology, will take longer and the manufacturer has said it hoped to have a vaccine adjusted for the South African variant in the second half of the year.

Ramping up the rollout of vaccinations in Brazil is now key to solving this crisis because, although the vaccines are not completely effective against this variant, anything that can reduce severe illness from COVID-19 and lower the burden on overwhelmed hospitals will help.

Other countries, where the variant has been identified, are scrambling to contain it by identifying and isolating those infected and their close contacts. It remains to be seen if these measures will be enough.

UK variant

As much as the UK has been applauded for its quick vaccine roll-out, it has also been criticised for its failure to implement lockdown and social distancing measures quickly enough last year.