Scientists say virus variants threaten to cause a pandemic

For weeks, many of the moods in the United States have been vibrant. Coronavirus cases, hospitalizations and deaths have plummeted from their highs, with millions of people being newly vaccinated daily. Restaurants, shops and schools have reopened. Some states, such as Texas and Florida, have completely abandoned precautionary measures.

In a measurable way, Americans have won the war against the coronavirus. Powerful vaccines and accelerated deployments ensure a return to normal in the end, including backyard barbecues, summer camps, and overnight parties.

However, it is becoming more and more apparent that it will be painful in the coming months. The so-called mutants spread, making the coronavirus more contagious and, in some cases, more deadly mutations.

The vaccine was approved late last year, paving the way for the end of the pandemic, but variants have hit the United Kingdom, South Africa and Brazil. New variants are appearing one after another — California one week, New York And Oregon Next. As they take root, these new versions of the coronavirus can postpone the end of the pandemic.

At this time, most vaccines appear to be effective against mutants. However, public health officials are deeply concerned that future iterations of the virus may be more resistant to the immune response, and Americans wait for regular rounds of booster shots or even new vaccines. is needed.

Devi Sridhar, a professor of public health at the University of Edinburgh in Scotland, said: “This pathogen seems to be constantly changing in ways that make it harder for us to control.”

Health officials acknowledge the urgent need to track these new viruses as they crawl across the United States. Already, B.1.1.7 is a highly contagious variant that has hit Britain and caused havoc on the European continent. Exponentially rising In the United States.

Limited genetic testing 12,500, Florida and Michigan. As of March 13th, the variant is about 27% new The number of cases nationwide increased from just 1% in early February.

Biden administration Promises a $ 200 million down payment Infusions aimed at enabling weekly analysis of 25,000 patient samples for viral variants to enhance surveillance. This is an ambitious goal. The country sequenced hundreds of samples each week in December and scaled up to about 9,000 per week as of March 27.

Until recently, researchers said the rise in B.1.1.7 was disguised as a reduction in overall infection rates, causing false reassurance for Americans and leading to prematurely relaxed restrictions. I will.

Sebastian Funk, a professor of infectious disease dynamics at the London School of Economics and Tropical Medicine, said: “We really obscure the view by summing them all up to give the total number of cases.”

Other variants identified in South Africa and Brazil, and some virus versions first seen in the United States, are slow to spread. However, they are also of concern because they contain mutations that reduce the effectiveness of the vaccine. Just this week, the Whistler Blackcomb Ski Resort in British Columbia was closed due to the outbreak of P.1, a variant that shattered Brazil.

Scientists say the world will be caught up in a sprint between vaccines and variants, and eventually the shot will win. However, each infection gives the coronavirus a chance to evolve further, so vaccination in the United States and elsewhere needs to be promoted. as soon as..

Infection is increasing again and has been driven to an uncertain degree by B.1.1.7 and other variants. Earlier this week, Dr. Rochelle Warrensky, director of the Centers for Disease Control and Prevention, said he felt a sense of “imminent ruin” and begged Americans to continue practicing masking and social distance.

“We are looking forward to-many promises and possibilities of where we are, and many reasons for hope,” she said. “But I’m scared now.”

“More infectious for more days”

The coronavirus should have been slow to change shape. Like all viruses, it will pick up mutations and evolve into thousands of mutants, scientists said at the beginning of the pandemic. But that hasn’t changed significantly over the years — a stupid virus, some call it.

The pathogen disobeyed those predictions. Dr. Michael Diamond, a viral immunologist at Washington University in St. Louis, said: “I never expected how soon it would happen.”

Mutants are only concerned if they are more contagious, cause more serious illness, or slow the immune response. All variants identified in the United Kingdom, South Africa, Brazil and California meet the standards.

B.1.1.7 first gained widespread attention. More contagious than 60 percent And 67% More deadly According to the latest estimates, than the original form of the virus.

The variant is the same as the original variant in how it spreads, but infected people Seems to carry more viruses And Because it’s long Katrina Lisgow, an evolutionary biologist at Oxford University, said. “You are more infectious for more days,” she said.

B.1.1.7 is so contagious that the UK has succeeded in reducing infections only after nearly three months of a strict stay-at-home order and an aggressive vaccination program. Still, the incident fell much more slowly than during similar blockades in March and April.

In continental Europe, a wave of B.1.1.7 cases continued for months, but was largely unnoticed under the constant turmoil of infection. Variant Wave is currently cresing.

The proportion of new cases daily in Poland has quintupled since mid-February, forcing most public facilities to close. Germany has doubled and night rallies in Berlin have been banned.

France caused by B.1.1.7 Three-quarters of new infections, Some hospitals had to move coronavirus patients to Belgium Release the bed. In Europe, about the same number of people die from Covid-19 every day at this time a year ago.

For too long, government officials have ignored the threat. Karl Pearson, Research Fellow of the London School of Economics and Tropical Medicine, said: “And the higher those plateaus, the worse the problem.”

In the United States, coronavirus infections began to decline rapidly in January, prompting many state leaders to resume operations and relax regulations soon.But scientists repeat Warned that the drop would not last.. After bottoming out in mid-March with about 55,000 cases and 1,500 deaths per day, some states, especially Michigan, began to see an upward trend.

Since then, the number nationwide has been steadily increasing. As of Saturday Counts per day were up to nearly 69,000, And the weekly average was 19% higher than it was two weeks ago.

Even when the number of cases is decreasing, researchers have questioned the idea that vaccination is the reason. Millions of Americans are vaccinated daily, but still only 31% receive a single dose of the vaccine, only 17% of the population is fully protected, and the majority are susceptible. I keep it.

Christian Andersen, a virologist at Scripps Research in San Diego, said: “And, like Texas, when we say Covid-19 is over, B.1.1.7 is coming and reminds us that we’re not right. No doubt.”

This variant is particularly prevalent in Florida, where the state has lifted restrictions and initially did not surge. Officials in other states cited this as the reason for the resumption. But now Florida’s prevalence is on the rise.

Variants can only be hidden by what scientists call seasonality. Sarah Kobey, an evolutionary biologist at the University of Chicago, states that respiratory infections are usually rare in Florida in the spring. Coronavirus infections peaked in Florida last summer as fever pushed people indoors and could happen again.

“I don’t think we’re out of the woods yet,” Dr. Coby said, referring to the whole country. “Without another wave this spring, I would really, really worry about autumn.”

Most vaccines are effective against B.1.1.7, but researchers are increasingly concerned about other mutants, including a mutation called E484K. (Scientists often properly call it “Eek”.)

This mutation has evolved independently in many variants around the world, suggesting that it provides a powerful survival benefit for the virus.

In laboratory studies, Pfizer-BioNTech And the Moderna vaccine appear to be slightly less effective against the mutant identified in South Africa, B.1.351. The variant contains an Eek mutation that appears to allow the virus to partially evade the body’s immune response.Vaccine made by Johnson & Johnson, AstraZeneca And Novavax It was even less effective against B.1.351.

Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Research Center in Seattle, said:

This mutation slightly alters the so-called peplomer on the surface of the coronavirus, making it a little harder for the antibody to catch and destroy the intruder.

Fortunately, this virus bag seems to contain some survival tricks that make it easier for scientists to find and block those defenses. Michel Nussenzweig, an immunologist at Rockefeller University in New York, said:

Eek mutations appear to be the virus’s primary defense against the immune system. South African researchers recently reported that a new vaccine directed against B.1.351 should dodge all other variants as well.

Pfizer, BioNTech, and Moderna have already tested newly designed booster shots for B.1.351, which should work for all variants known to blunt the immune response.

However, instead of a new vaccine against the variant, it may be just as effective for Americans to get a third dose of Pfizer-BioNtech or Moderna vaccine in 6 months to a year, a national director said. One Dr. Anthony S. Forch said. National Institute of Allergy and Infectious Diseases.

It keeps antibody levels high for each recipient and overwhelms all mutants. This is a more practical strategy than creating a specialized vaccine for each new mutant that emerges.

“My only concern about chasing all variants is that I play most of the Whac-A-Mole, because they go up and up,” Dr. Forch said.

Many scientists believe that somehow a new coronavirus has taken root. Multiple variants can be prevalent in the country at the same time, as is the case with the common cold coronavirus and flu. To keep them away, you may need an annual injection, like a flu vaccine.

The best way to stop the emergence of dangerous variants is to control the incident now and vaccinate the majority of the world, not just the United States, as soon as possible. If the vital pockets of the Earth remain unprotected, the virus will continue to evolve in dangerous new ways.

Rosalin Doego, an epidemiologist at the London School of Economics and Tropical Medicine, said:

Still, she said, “Even if it changes again, it’s very likely that it will happen, but we’re in a much stronger position to deal with it than it was a year ago.” I added.