The devastating increase in new daily cases of COVID-19 in the United States has started to decline slowly and vaccines are beginning to protect millions of the country’s most vulnerable people.
But any respite from the worst chapter of the pandemic so far can be reversed – or worsened – by new variants of the coronavirus that, experts say, can present a variety of challenges in keeping the virus under control.
Three specific variants have triggered alarms so far: B.1.1.7, which has been identified in the United Kingdom, B.1.351 in South Africa and P.1 in Brazil, all of which have been detected in the United States. Experts believe that B.1.1.7. it can be “50 to 70 percent more contagious” compared to previous variants, meaning that more people are infected.
This could pave the way for more hospitalizations and, eventually, more deaths, as England has suffered in recent months. There, a huge increase in cases traced back to the new variant left hospitals struggling to accommodate the country’s growing number of COVID-19 patients, and the country set new records for the national number of daily deaths. The Centers for Disease Control and Prevention warned that B.1.1.7 may become the dominant variant in the United States in March.
B.1.351 has raised concerns about its apparent ability to affect the performance of respective COVID-19 vaccines from Moderna and Pfizer-BioNTech, but so far there is no evidence that it makes both vaccines completely ineffective. P.1, in turn, is worrying because it appeared and spread widely in a Brazilian city whose population had already been devastated by the virus, pointing to the possibility that it could cause reinfection. According to the CDC, these variants also appear to “spread more easily and quickly” compared to others.
“These variants can change the course of this pandemic, and that is definitely worrying,” said Dr. Krutika Kuppalli, an assistant professor of medicine at South Carolina Medical University.
It is normal for a virus, especially one that circulates as widely as the coronavirus now, to mutate over time.
“When you have such high levels of infection, you are giving the virus many chances to adapt,” said Ryan McNamara, a researcher at the University of North Carolina School of Medicine.
Most mutations do not change anything significant about the virus or the disease it causes, and some can even be harmful. But sometimes, useful mutations emerge that, in the right circumstances, can allow that version of the virus to spread better than in the past.
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Researchers are still evaluating how exactly these variants differ from their predecessors, as well as how they affect the effectiveness of existing treatments and vaccines for COVID-19, including those that have not yet been authorized in the U.S. A January study from the United Kingdom suggested that B.1.1.7 may cause more severe cases of the disease, but the CDC emphasizes that “more studies are needed to confirm this finding”.
In addition to concerns about increased hospitalizations and deaths, another spike in cases could mean that the U.S. sees an increasing proportion of “long-haulers” or patients whose symptoms persist for months after the initial infection, said Kuppalli. This condition can also have a significant impact on the country’s health system, not to mention the quality of life and emotional well-being of the patients themselves, she added.
Despite the frightening prospects raised by the new variants, the United States is by no means powerless. During a press conference on January 21 at the White House, Dr. Anthony Fauci, the country’s leading infectious disease specialist, emphasized that he and other experts “are paying close attention” to these variants and added that “there are alternative plans if we always have to modify the vaccine ”.
Here is a look at how viruses mutate and why tracking new variants and stepping up your own personal precautions are critical to controlling the pandemic.
How do viruses mutate?
When the coronavirus infects a new host, it uses that person’s cells to make copies of itself. Some are bound to have errors or mutations in their genome that make the copy slightly different from the original virus that caused the infection.
“Viruses mutate all the time,” said Stanley Perlman, a physician and coronavirus researcher at the University of Iowa. “And most of the time, these mutations aren’t going anywhere because they don’t help the virus. In fact, some of them can kill the virus. “
But mutations can also give the virus an advantage.
In the context of this pandemic, the normal virus replication process has been conducted by more than 100 million people worldwide who are known to have been infected in the past year or so. This means that the virus has had ample opportunity to acquire mutations and potentially become better at infecting us. All three variants on the CDC’s radar have mutations in their peak proteins, which are the part of the virus responsible for successfully invading our cells in the first place.
This is not even the first time that the virus has mutated to become more infectious since the pandemic began. According to the World Health Organization, the first strain of coronavirus initially detected in Wuhan has been replaced by others that carried a specific mutation called D614G.
Nature magazine reported that in June 2020, “the D614G mutation was found in almost all [coronavirus] samples around the world. “
Several research teams in the United States discovered last fall that this mutation altered the virus’s spike protein so that it could enter and infect cells better. They determined that it allowed the virus to replicate faster and become more transmissible, but that the mutation may also have made it more vulnerable to being neutralized by antibodies that people acquire through vaccination.
The main goal of a virus will always be “to support itself”, explained McNamara, and that particular pathogen has been infecting humans for a very short period of time. The relatively large number of variants the world has detected in the past year, he said, indicates that the coronavirus is still adapting to its new host. The only way to stop this natural process is to stop the spread of the virus itself.
What the U.S. can do to keep variants away
Some countries perform regular and random sequencing of the virus genome when someone tests positive within their borders, giving researchers an idea of which variants are dominant and where they spread.
In comparison to other nations, the USA has not implemented such a robust nationalized sequencing program. According to the Associated Press, “less than 1 percent of positive results [virus] specimens ”are sequenced here, while“ Britain sequences about 10 percent ”.
Volunteers go door-to-door distributing COVID-19 home test kits in an effort to stop the spread of the new SARS-CoV-2 variant in Ealing, West London, Great Britain, February 3, 2021. Henry Nicholls / Reuters
Experts say the United States can and should do more, given the amount of viruses circulating and the possibility that a notable new variant could also originate in the states. Researchers are already eyeing one, named CAL.20C, which was first detected in California last month.
The CDC said it is stepping up its sequencing efforts, including collecting 750 samples of the virus a week from “state health departments and other public health agencies” for sequencing.
Vaccination will undoubtedly remain a crucial public health tool as always, and it is unlikely that any new variant would completely erase the high levels of protection offered by the two vaccines authorized for emergency use. Pfizer and BioNTech have declared that their vaccine still appears to be protective against “key mutations” in B.1.1.7 and B.1.351.
Companies are also developing booster injections that can improve immune responses against new variants of the virus, as published by Bloomberg News. Moderna announced in late January that it expects its existing two-dose vaccine regimen “to be protective against emerging strains [of the virus] detected so far ”, but plans to test a“ reinforcement candidate ”that would provide more protection against B.1.351“ and potentially future strains ”.
Both vaccines induce a “polyclonal” response, which means that they induce the body to create several different types of antibodies that target different parts of the virus. The virus would have to “modify itself extensively,” said McNamara, to escape entirely the protection generated by a vaccine.
Variants have already demonstrated the ability to partially reduce the vaccine’s effectiveness. According to Reuters, the vaccine developed by Johnson & Johnson – which the company reported to have an overall effectiveness of 66 percent – produced different results depending on the region where it was tested during clinical trials. In the USA, “effectiveness reached 72 percent”, but in South Africa, where B.1.351 “accounted for 95 percent of reported COVID-19 cases” during that trial, effectiveness reached 57 percent.
According to the World Health Organization, the term “vaccine efficacy” refers to the percentage by which the incidence of the disease is reduced in those who are vaccinated compared to those who are not. In other words, it focuses on prevention. But in addition to completely preventing the disease, vaccines can also decrease the chances of a person becoming seriously ill. Reuters noted that the Johnson & Johnson vaccine was 89 percent effective in “preventing serious diseases in South Africa”.
According to Fauci, the existence of coronavirus variants reinforces the importance of vaccinating the American public as quickly and efficiently as possible.
“If we can implement our vaccine programs with the vaccines we currently have and bring the level of replication and dynamics of the virus in the community to a very low level, the virus will not mutate as efficiently as when an explosion of infections occurs,” Fauci said to PBS NewsHour anchor and editor-in-chief Judy Woodruff.
The fact is that, to prevent the spread of these variants and decrease the likelihood of new ones in the United States, we already have the tools we need: the same pandemic precautions that have been in place since the country closed in March. last year.
“We know how to prevent the spread to some extent – to a large extent – and by preventing the spread, we prevent the disease,” said Perlman.
Strict adherence to protocols such as social detachment, limiting contact with people outside our home and wearing a mask reduces opportunities for mutating the virus and makes it less likely that new variants will emerge.
“This is a collaborative effort,” said Kuppalli. “So we need everyone to play their part.”
Editor’s note: Johnson & Johnson is a financier for PBS NewsHour.