The TLDR: Over the weekend, UK Prime Minister Boris Johnson warned that the UK variant of the virus was not just more infectious—but also more lethal. As multiple variants of the virus spread across the world, experts are growing increasingly worried about the pandemic spinning out of control—just as the first vaccines roll out. We look at the latest research on the new variants, and how these will affect us in the months ahead.

A quick recap

As we explained at length earlier, viruses spread by replicating themselves at an astonishing speed. 

• Like all living things, viruses are made up of protein molecules—which in turn are constructed of 20 types of amino acid. 
• Think of them as Lego blocks. How you combine these amino acids determines what kind of protein you end up with. 
• So when a virus produces a copy of itself, there are routine changes and sometimes ‘copying errors’—and that may cause changes in a protein molecule's behaviour.  
• These ‘errors’ can make a virus weaker, more harmful—or have no effect at all. 
• The coronavirus has picked up an average of two mutations a month—around 25 since the beginning of the pandemic. The great majority of these have been minor. 

Point to note: The genetic code of a virus can be in the form of DNA (like humans) or RNA. Most RNA viruses lack a “proofreader”—which is a protein that checks for mistakes and corrects them. But coronavirus is an exception. This means it mutates more slowly—but also more effectively in order to evade the body’s immune system. 

Ok, so a variant is a kind of mutation?

No, the words ‘variant’, ‘strain’ and ‘mutation’ mean different things. 

The strain: in this case is Sars-Cov-2—which is the cause of the disease called Covid-19. This coronavirus is a strain of a larger family of coronaviruses, which includes other strains such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) that caused severe respiratory illnesses in the past.

Mutation: is the process by which a virus changes—as we explained in the recap.

The variant: When a virus undergoes significant types of mutations that causes it to behave differently from the original virus, then it becomes a variant. And this is what everyone is worried about. 

How many variants are there?

There are three major “variants of concern.” All of them have mutations in the spike protein—the part of the virus that helps it attach itself to a human cell, and then invade it. But they are not identical.

The UK variant: The scientific term for this variant is B.1.1.7. It was first identified in the UK, and now has been detected in at least 60 countries. It has 24 mutations—including a significant one called N501Y—which is located on the most important part of the spike—where it first makes contact with the surface of our cells.

The South Africa variant: is called 501Y.V2 or B.1.351 also has the N501Y mutation, but it is not identical to its UK cousin. It has more than 20 mutations, and has now been reported in 23 countries and territories. But this one has another mutation called E484K which makes it worrying (more on that next).

The Brazil variant: is called P.1 or B.1.1.248, and was first detected in samples from Manaus in the Amazonas state in northern Brazil in mid-December. It too has the N501Y mutation—and also the E484K.

Why are there so many? 

Because the sheer numbers of infected people is extremely high. Each infection is a chance to replicate and therefore mutate. As The Atlantic notes: “Over time, though, sets of mutations can layer on top of one another and accumulate, and the virus begins to function differently.”

And as infections spread across populations, what may be rare in a limited outbreak becomes more likely or frequent, as The Atlantic explains:

“The variants may have evolved in immunocompromised patients who were infected with the virus for months. Normally… ‘your immune system is going to town on it. It’s really trying to beat it up.’ But immunocompromised patients mount weaker immune responses. ‘It becomes almost like a training course for how to live with the human immune system,’ she says. That may be why these variants have so many new mutations at once, as if a year or two of evolution has been compressed into months. This is probably quite rare, but with tens of millions of infections around the globe, rare things will show up.” 

And these variants are more dangerous?

The data on Brazil variant is sparse, and scientists are still looking at data for the others. But here’s what we know about them.

The South Africa/Brazil variant: share a potentially dangerous E484K mutation. A recent (not yet peer reviewed) study in South Africa took blood plasma samples from six patients who had recovered from Covid. They then tested how their antibodies performed when faced with the new variant. Their conclusion: the new variant successfully evaded the antibodies created from the original infection. This is called “immune escape.” 

Separately in Brazil, researchers documented the case of a 45-year old patient who was reinfected with the new variant. The second bout was far more severe. There is also evidence that it may make existing Covid treatments less effective:

“Regeneron, a company that has developed a cocktail of two monoclonal antibodies as a therapy for patients with the illness, reported that 501Y.V2 may be able to evade one of the antibodies in its mix. The drug is still effective, but subsequent mutations could render it less so.”

Point to note: The South Africa variant has another twist. The original virus is negatively charged at the point where it attaches itself to the human cell—which is also negatively charged. Hence, they tend to repel each other which slows down the infection. Unfortunately, this new variant is positively charged… and, well, opposites attract.

The UK variant: which we explained at length in December, is more infectious—and apparently more deadly.  Experts think it may be up to 70% more transmissible or infectious—while other estimates put the number between 30% and 50%. 

The mutation on its spike protein allows it to bind more tightly to the receptors on a human cell. As one expert explains: “That means it takes less virus to infect you… That tighter binding also means that it can replicate more efficiently.” And once infected with the new variant, a person also sheds more virus—which makes them vastly more infectious, creating “a wicked cycle.” 

Also more deadly? At first, UK researchers did not think the variant caused more severe illness. But the latest data—limited though it is—suggests it may be 30% more deadly: “For example, with 1,000 60-year-olds infected with the old variant, 10 of them might be expected to die. But this rises to about 13 with the new variant.” That said, most experts say it is too early to draw definitive conclusions. 

Also this: “Because it can spread more easily, it can also quickly overwhelm medical systems, turning previously survivable bouts with the virus into perilous ones if hospitals are full and medical care is limited.”

What is most worrying: is that the UK variant is spreading the fastest—triggering alarm across Europe. For example, Denmark where cases involving the variant are increasing 70% a week—despite a strict lockdown! Now, the actual number of cases is low and dropping, but Danish experts warn that as this variant becomes dominant, that number will suddenly and uncontrollably surge. Here’s how the Danish PM explained it:

“[I]magine sitting in the top row of Copenhagen’s Parken Stadium, a soccer arena with a capacity of 38,000 people. A dripping tap is filling it up, one drop the first minute, two drops the second, four drops the third. At that rate, Frederiksen said, the park will be filled in 44 minutes. But it will seem almost empty for the first 42 minutes.”

What about India?

We’re in pretty good shape so far. As of now, 150 people have tested positive for the UK variant. But the number of active cases continues to plummet—and is only 185,000 right now. And that unexplained drop—when Indians are stepping out more than ever—is a bit of a mystery. Scientists don’t exactly know why we’ve been lucky, but one possible cause: maybe a less infectious variant has mutated in India. We simply don’t have the genetic data to figure out what’s going on.

Won’t vaccines fix the variants?

As of now, all we know is that the Pfizer vaccine works against the UK variant. It has not been tested on the South African one. But the longer the pandemic stretches, and the more often the virus replicates itself, the more likely it is that new variants will emerge— and there is a strong possibility that some of them will make existing vaccines either less effective or entirely ineffective. So the big priority is to get people vaccinated, and as quickly as possible—because when we stop transmission, we block the possibility of mutation. 

The bottomline: The true danger to our global health is our own selfishness. Richer nations have bought most of the available vaccines—leaving poorer nations unprotected. And that disparity poses a real hazard, as a health policy expert points out:

“The longer the virus is allowed to continue in different parts of the world where we don’t have a vaccine, the greater the danger of new variants that could be more aggressive, more virulent or transmissible.”

Reading list

• Wall Street Journal via Mint offers an excellent overview of the various variants.
• Washington Post via NDTV explains why the world is worried about the UK variant.
• Bloomberg News via Indian Express lays out how vaccine disparity poses a real hazard. 
• New York magazine has the most on the Brazil variant, while Vox explains the South African one.
• A very good read: New Yorker’s analysis of whether vaccines can win the race against the variants.