For weeks, the weather in much of the United States has been optimistic. Coronavirus cases, hospitalizations and deaths have dropped dramatically from their highs, and millions of people are being vaccinated every day. Restaurants, shops and schools have reopened. Some states, like Texas and Florida, have abandoned precautions altogether.
In measurable ways, Americans are winning the war against the coronavirus. Powerful vaccines and accelerated implementation almost guarantee an eventual return to normality – for backyard barbecues, summer camps and sleepovers.
But it is increasingly clear that the coming months will be painful. The so-called variants are spreading, carrying mutations that make the coronavirus more contagious and, in some cases, more deadly.
Even though vaccines were authorized at the end of last year, illuminating a path to an end to the pandemic, variants were defeating Britain, South Africa and Brazil. New variants continued to emerge – in California in one week, in New York and Oregon in the following. As they take root, these new versions of the coronavirus threaten to postpone the end of the pandemic.
At the moment, most vaccines appear to be effective against the variants. But public health officials are deeply concerned that future iterations of the virus may be more resistant to the immune response, requiring Americans to line up for regular rounds of booster doses or even new vaccines.
“We don’t have evolution on our side,” said Devi Sridhar, a professor of public health at the University of Edinburgh in Scotland. “This pathogen always seems to be changing in a way that makes it more difficult for us to suppress.”
Health officials recognize the urgent need to track these new viruses as they spread across the United States. B.1.1.7, the highly contagious variant that hit Britain and is causing havoc in continental Europe, is growing exponentially in the United States.
Limited genetic testing has revealed more than 12,500 cases, many in Florida and Michigan. On March 13, the variant accounted for about 27% of new cases across the country, compared to just 1% in early February.
The Biden government has promised an “initial payment” of $ 200 million to increase surveillance, an infusion designed to allow the analysis of 25,000 patient samples a week for variants of the virus. It is an ambitious goal: the country was sequencing only a few hundred samples a week in December, increasing the scale to about 9,000 a week on March 27.
Until recently, the rise of B.1.1.7 was camouflaged by declining rates of infection in general, leading Americans to a false sense of security and leading to prematurely relaxed restrictions, the researchers say.
“The best way to think about B.1.1.7 and other variants is to treat them as separate epidemics,” said Sebastian Funk, professor of infectious disease dynamics at the London School of Hygiene and Tropical Medicine. “We are really obscuring the view, adding all of them to give an overall number of cases.”
Other variants identified in South Africa and Brazil, as well as some versions of viruses seen for the first time in the United States, have spread more slowly. But they are also worrisome, because they contain a mutation that decreases the effectiveness of vaccines. This week, an outbreak of P.1, the variant that crushed Brazil, forced the Whistler Blackcomb ski resort to close in British Columbia.
The world is caught up in a race between vaccines and variants, and the shots will eventually win, say the scientists. But because each infection gives the coronavirus a chance to evolve further, vaccinations in the United States and elsewhere must occur as quickly as possible.
Infections are increasing again, driven to an uncertain degree by B.1.1.7 and other variants. Earlier this week, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, pleaded with Americans to continue practicing masking and social detachment, saying she felt a sense of “impending doom.”
“We have a lot to look forward to – lots of promises and potential from where we are and so many reasons to hope,” she said. “But now I’m scared.”
‘More infectious for more days’
The coronavirus should be slow to change shape. Like all viruses, it would take mutations and evolve into thousands of variants, scientists said at the beginning of the pandemic. But it wouldn’t change significantly for years – a stupid virus, as some called it.
The pathogen challenged these predictions. “We expected the virus to change,” said Dr. Michael Diamond, a viral immunologist at Washington University in St. Louis. “We didn’t anticipate how quickly this would happen.”
A variant is of concern only if it is more contagious, causes more serious illnesses or dulls the immune response. All variants identified in Great Britain, South Africa, Brazil and California meet the criteria.
B.1.1.7, the first to receive widespread attention, is about 60 percent more contagious and 67 percent more deadly than the original form of the virus, according to the latest estimates.
The variant does not differ from the original in the way it spreads, but infected people appear to carry more of the virus and for longer, said Katrina Lythgoe, an evolutionary biologist at the University of Oxford. “You are more contagious for more days,” she said.
B.1.1.7 is so contagious that Britain managed to reduce infections only after almost three months of strict home orders, in addition to an aggressive vaccination program. Even so, cases fell much more slowly than during a similar block in March and April.
In continental Europe, a wave of B.1.1.7 cases has been brewing for months, most of them unnoticed under a constant wave of infections. The variant wave is growing.
Poland’s rate of new daily cases has quintupled since mid-February, forcing the closure of most public places. Germany’s doubled, prompting a ban on nightly meetings in Berlin.
In France, where B.1.1.7 is causing three quarters of new infections, some hospitals have had to move coronavirus patients to Belgium to free up beds. Almost as many people die every day of Covid-19 in Europe as a year ago.
For a long time, government officials ignored the threat. “The plateaus of cases can hide the emergence of new variants,” said Carl Pearson, a researcher at the London School of Hygiene and Tropical Medicine. “And the higher these plateaus, the worse the problem.”
In the United States, coronavirus infections began to decline rapidly in January, prompting many state leaders to reopen companies and ease restrictions. But scientists have repeatedly warned that the fall would not last. After the rate hit rock bottom in about 55,000 cases and 1,500 deaths a day in mid-March, some states – notably Michigan – started to increase.
Since then, national numbers have been steadily increasing. On Saturday, the daily count was almost 69,000, and the weekly average was 19 percent higher than the number two weeks earlier.
Even when cases were declining, the researchers questioned the notion that vaccines were the reason. Millions of Americans are immunized every day, but even now only 31% have received a single dose of the vaccine and only 17% of the population has full protection, leaving a large majority susceptible.
“The fact is, we’re still in a position where we don’t have enough vaccinated people,” said Kristian Andersen, virologist at Scripps Research in San Diego. “And if we, like Texas, say we are done with Covid-19, B.1.1.7 will come and remind us that we are not right. I have no doubt about that. “
The variant is particularly widespread in Florida, where the state lifted restrictions and initially did not see an increase. Officials from other states cited this as a justification for the reopening. But now Florida’s infection rate is rising.
The variant may have been obscured only by what scientists like to call seasonality. Respiratory infections are generally rare in Florida in the spring, noted Sarah Cobey, an evolutionary biologist at the University of Chicago. Coronavirus infections peaked in Florida last year, in the summer, when the heat drove people into the home, which can happen again.
“I still don’t think we’re out of danger,” said Cobey, referring to the country in general. “If we don’t have another wave this spring, I’m going to be very, very concerned about the fall.”
While most vaccines are effective against B.1.1.7, researchers are increasingly concerned about other variants that contain a mutation called E484K. (Scientists often refer to it, appropriately, as “Eek.”)
This mutation has evolved independently in many variants around the world, suggesting that it offers the virus a powerful survival advantage.
In laboratory studies, the Pfizer-BioNTech and Moderna vaccines appear to be somewhat less effective against B.1.351, the variant identified in South Africa. This variant contains the Eek mutation, which appears to allow the virus to partially bypass the body’s immune response . Vaccines manufactured by Johnson & Johnson, AstraZeneca and Novavax were even less potent against B.1.351.
“I think for the next year or two, E484K will be the most worrying mutation,” said Jesse Bloom, evolutionary biologist at Fred Hutchinson Cancer Research Center in Seattle.
The mutation slightly alters the so-called peak protein located on the surface of the coronavirus, making it a little more difficult for antibodies to cling to and destroy the invader.
The good news is that the virus appears to have only a few survival tricks in its bag, which makes it easier for scientists to find and block these defenses. “I’m feeling pretty good about the fact that there aren’t many options,” said Michel Nussenzweig, an immunologist at Rockefeller University in New York.
The Eek mutation appears to be the virus’s main defense against the immune system. Researchers in South Africa recently reported that a new vaccine directed against B.1.351 should also avoid all other variants.
Pfizer, BioNTech and Moderna are already testing newly designed booster injections against B.1.351 that should work against any variants known to dull the immune response.
Instead of a new variant vaccine, however, it can be just as effective for Americans to receive a third dose of the Pfizer-BioNtech or Moderna vaccines in six months to a year, said Dr. Anthony S. Fauci, head of the National National Institute of Allergy and Infectious Diseases.
This would keep antibody levels high at each receptor, outpacing any variant – a more practical strategy than making a specialized vaccine for each new variant that emerges, he said.
“My only concern in pursuing all the variants is that you would almost play Whac-A-Mole, you know, because they will keep on coming and going,” said Fauci.
One way or another, the new coronavirus is here to stay, many scientists believe. Multiple variants may be circulating in the country at the same time, as is the case with the common cold and flu coronaviruses. Keeping them away may require an annual injection, like the flu vaccine.
The best way to prevent dangerous variants from emerging is to keep cases inactive now and immunize the vast majority of the world – not just the United States – as quickly as possible. If significant parts of the globe remain unprotected, the virus will continue to evolve in dangerous new ways.
“This could be something that we will have to deal with for a long time,” said Rosalind Eggo, an epidemiologist at the London School of Hygiene and Tropical Medicine.
Still, she added: “Even if it changes again, which is very likely to happen, we are in a better and much stronger position than we were a year ago to deal with.”