In latest days, the world has watched with curiosity and rising alarm as scientists in the U.Ok. have described a newly recognized variant of the coronavirus that seems to be extra contagious than, and genetically distinct from, extra established variants. Initial research of the new variant prompted Prime Minister Boris Johnson to tighten restrictions over Christmas, and spurred officers in the Netherlands, Germany and different European nations to ban journey from the U.Ok.
The new variant is now the focus of intense debate and evaluation, and nations round the world are scouring their very own databases to see whether it is circulating inside their borders. On Wednesday, well being officers in Hong Kong reported that two college students who returned from the U.Ok. this month seem to have been contaminated with the variant; and authorities in Italy reported a case there, with no obvious hyperlink to the U.Ok. Here’s a few of what scientists have discovered thus far.
Is the U.Ok. variant some sort of new supervirus?
No. It’s only one variation amongst many who have arisen as the coronavirus SARS-CoV-2 has unfold round the world. Mutations come up as the virus replicates, and this variant — referred to as B.1.1.7 — has acquired its personal distinctive set of them.
What is uncommon about it?
The variant got here to the consideration of researchers in December, when it started to show up extra regularly in samples from components of southern England. It turned out to have been collected from sufferers as early as September.
When researchers took a detailed take a look at its genome, they had been struck by the comparatively massive variety of mutations — 23, all informed — that it had acquired. Most mutations that come up in the coronavirus are both dangerous to the virus or don’t have any impact a technique or one other. But a lot of the mutations in B.1.1.7 regarded as if they may probably have an effect on how the virus unfold.
Is it extra contagious than different viruses?
It seems so. In preliminary work, researchers in the U.Ok. have discovered that the virus is spreading rapidly in components of southern England, displacing a crowded area of different variants which were circulating for months.
However, a virus lineage changing into extra widespread will not be proof that it spreads quicker than others. It might develop extra widespread merely by way of luck. For occasion, a variant would possibly begin out in the center of a crowded metropolis, the place transmission is straightforward, permitting it to make extra copies of itself.
Still, the epidemiological proof gathered so removed from England does appear to recommend that this variant is superb at spreading. In locations the place it has change into extra widespread, the total variety of coronavirus circumstances is spiking. Neil Ferguson, an epidemiologist at Imperial College London, estimates that the variant has an elevated transmission fee of 50 to 70 % in contrast with different variants in the United Kingdom.
Some scientists have raised the risk that the improve in transmission is not less than partly the results of the way it infects youngsters. Normally, youngsters are much less doubtless than youngsters or adults to get contaminated or move on the virus. But the new variant could make youngsters “as equally susceptible as adults,” stated Wendy Barclay, authorities adviser and virologist at Imperial College London.
To affirm that the variant really is extra contagious, researchers are actually operating laboratory experiments on it, observing up shut the way it infects cells.
Researchers have already used such experiments to analyze a mutant that arose earlier in the pandemic, known as 614G. That variant proved to be extra transmissible than its predecessors, research in cell tradition and animals discovered.
But disciplined containment measures labored simply as nicely in opposition to 614G as different variants. The similar is probably going true for B.1.1.7. “According to what we already know, it does not alter the effectiveness of social distancing, face masks, hand washing, hand sanitizers and ventilation,” Dr. Muge Cevik, an infectious illness specialist at the University of St. Andrews School of Medicine, said on Twitter.
Does it cause more severe disease?
There is no strong evidence that it does, at least not yet. But there is reason to take the possibility seriously. In South Africa, another lineage of the coronavirus has gained one particular mutation that is also found in B.1.1.7. This variant is spreading quickly through coastal areas of South Africa. And in preliminary studies, doctors there have found that people infected with this variant carry a heightened viral load — a higher concentration of the virus in their upper respiratory tract. In many viral diseases, this is associated with more severe symptoms.
Where did this unusual variant come from?
That is now a question of intense debate. One possibility is that the variant gained its array of new mutations inside a special set of hosts.
In a typical infection, people pick up the coronavirus and become infectious for a few days before showing symptoms. The virus then becomes less abundant in the body as the immune system marshals a defense. Unless patients suffer a serious case of Covid-19, they typically clear the virus completely in a few weeks at most.
But sometimes the virus infects people with weak immune systems. In their bodies, the virus can thrive for months. Case studies on these immunocompromised people have shown that the virus can accumulate a large number of mutations as it replicates in their bodies for a long period of time.
Over time, researchers have found, natural selection can favor mutant viruses that can evade the immune system. Researchers have also suggested that the evolution of the variant might have been additionally driven by medicine given to such patients. Some mutants might be able to withstand drugs such as monoclonal antibodies.
Other scientists have suggested that the virus could have gained new mutations by spreading through an animal population, like minks, before re-entering the human population. Such “animal reservoirs” have become a focus of intense interest as more animal infections have been detected.
Is the variant already circulating in the U.S.?
Not yet, as far as anyone knows. But that does not mean it hasn’t already reached the United States. British scientists have established a much stronger system to monitor coronaviruses for new mutations. It’s conceivable that someone traveling from the United Kingdom has brought it with them. Now that the world knows to look for the variant, it may turn up in more countries.
Will the variant render the new vaccines ineffective?
No. Most experts doubt that it will have any great impact on vaccines, although it’s not yet possible to rule out any effect.
The U.S. Food and Drug Administration has authorized two vaccines, one from Moderna and the other from Pfizer and BioNTech. Both vaccines create immunity to the coronavirus by teaching our immune systems to make antibodies to a protein that sits on the surface of the virus, called spike. The spike protein latches onto cells and opens a passageway inside. Antibodies produced in response to the vaccines stick to the tip of the spike. The result: The viruses can’t get inside.
It is conceivable that a mutation to a coronavirus could change the shape of its spike proteins, making it harder for the antibodies to gain a tight grip on them. And B.1.1.7’s mutations include eight in the spike gene. But our immune systems can produce a range of antibodies against a single viral protein, making it less likely that viruses can easily escape their attack. Right now, experts don’t think that the variant will be able to evade vaccines. To confirm that, researchers at the Walter Reed Army Institute of Research are analyzing the changes to the structure of its spike protein.
Dr. Moncef Slaoui, the head scientific adviser to Operation Warp Speed, the federal effort to deliver a vaccine to the American public, said that the new variant reported in Britain was unlikely to affect the efficacy of a vaccine.
At some point — “some day, somewhere” — a variant of the virus may make the current vaccine ineffective, he said, but the chance of that happening with this vaccine is very low. Nevertheless, he said, “we have to remain absolutely vigilant.”
But Kristian Andersen, a virologist at Scripps Research Institute, thinks it is too early to dismiss the risk to vaccines. If the U.K. variant evolved to evade the immune system in immunocompromised patients, those adaptations might help it avoid vaccines. The vaccines would not become useless, but they would become less effective. Fortunately, experiments are underway to test that possibility.
“We don’t know, but we’ll know soon,” Dr. Andersen said.
Benjamin Mueller and Katie Thomas contributed reporting to this article
[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]