After a brutal summer surge driven by the highly contagious Delta variant, the coronavirus has backfired again.
United States is recording About 90,000 new infections a day, down more than 40 percent since August. Hospitalizations and deaths are also falling.
The crisis is not over everywhere – the situation in Alaska especially terrifying — but nationally, the trend is clear, and expectations are rising that the worst is finally behind us.
Over the past two years, the pandemic has crashed into the country in waves, flooding hospitals and then receding, only to return after Americans let down their guard.
It is difficult to isolate the reasons why viruses flow and flow in this way, and the future is still hard to predict.
But as winter approaches, there are real reasons for optimism. Around 70 percent of adults have been fully vaccinated, and many children under the age of 12 are likely to be eligible For his shots in just a few weeks. federal regulator may authorize soon First antiviral pill for covid-19.
“Certainly, we are definitely in a better place this year than we were last year,” said Dr. Nahid Bhadelia, director of the Center for Emerging Infectious Diseases Policy and Research at Boston University.
But the pandemic is not over yet, scientists warn. Nearly 2,000 Americans are still dying every day, and another winter surge is plausible. Given how many Americans remain unconnected, and how much remains unknown, it is too early to drop basic precautions, he said.
“We’ve had this happen over and over again, where we let go of the pedal too quickly,” said Dr. Bhadelia. “It behooves us to be a little more cautious as we’re trying to get to that finish line.”
When the first wave of cases hit the United States in early 2020, there was no Covid vaccine, and essentially no one was immune to the virus. The only way to flatten the temporal curve was to change individual behavior.
That was the goal in the first round of stay-at-home orders, business closures, mask mandates and bans on large gatherings. There is still debate as to which of these measures was most effective, but several studies show that collectively, they made a difference, keeping people at home And Stopping the growth of case numbers.
These policies, combined with voluntary social distancing, most likely helped end the initial surge, the researchers said.
“And then the measures will be lifted, perhaps the memories will fade,” said Jennifer Nuzzo, an epidemiologist at Johns Hopkins University.
Eventually, cases will rise again, and similar patterns will emerge. Businesses and local governments would reimpose restrictions, while those who had begun to venture out into the world again would bow down and unmask.
For example, during last winter’s increase, the percentage of Americans who reported going to bars or restaurants or attending large events declined, according to the U.S. According to covid-19 trends and impact survey, which has surveyed an average of 44,000 Facebook users daily since April 2020.
“The curve is shaped by public awareness,” Dr Nuzzo said. “We are swinging between crisis and complacency.”
Delta came during a period of deep pandemic fatigue, and at a time when many vaccinated Americans felt they could finally rest. The data suggest that the new variant induced a less profound behavioral change than the previous waves.
in mid-July, Only 23 percent of Americans said They have always worn masks in public since March 2020, according to the Institute for Health Metrics and Evaluation at the University of Washington, which compiles data from multiple sources.
By August 31, at the peak of the delta wave, that figure had risen to 41 percent, though it remained well below the 77 percent of people who reported wearing masks during the winter.
“If you look around you, people are leading a normal life or a pre-Covid life,” said Dr. Christopher Murray, director of the institute.
Nevertheless, even minor changes in behavior can help slow transmission, especially in combination, and delta driven change at both the individual and organizational levels. Schools took new precautions, companies postponed reopenings, and organizations canceled events, leaving fewer opportunities for the virus to spread.
Meanwhile, more temperate autumn weather arrived, making it possible for Americans to socialize outside in many areas of the country where the virus is less likely to spread.
“We’re in a shoulder season where it’s cooler in the south in the middle of summer and it’s warmer in the north in the middle of winter,” said David O’Connor, a virologist at the University of Wisconsin-Madison.
Behavior change is a temporary, short-term way to ease matters. The true end of the pandemic will be through immunity.
The delta wave was the first major, national surge after vaccines became widely available, providing many adults with substantial protection against the virus. (delta maybe even lead To get more Americans vaccinated.)
At the same time, the variant was so contagious that it spread rapidly through vulnerable populations, conferring natural immunity on many non-vaccinated Americans.
Although neither vaccination nor prior infection provide complete protection against the virus, they dramatically reduce the odds of catching it. So by September, the virus had a tough time finding hospitable hosts.
“Delta is running out to infect people,” said Jeffrey Shaman, an infectious disease epidemiologist at Columbia University.
The fact that case numbers are falling does not mean the country has reached herd immunity, a goal that Many scientists now believe is unattainable. But increasing levels of vaccination and infection, along with more minor behavioral changes, may be enough to put an end to the increase.
“It’s a combination of immunity, but people are also careful,” said Joshua Salomon, an infectious disease specialist and modeler at Stanford University.
Indeed, the scientists said that a combination of factors, which can vary in different parts of the country, will ultimately determine when and why the virus increased and subsided.
“The different waves and waves depend on how big the waves were before that one, how many people were vaccinated, when schools reopened, different variants,” said Alessandro Vespignani, Director of the Network Science Institute at Northeastern University in Boston.
There is also some randomness involved, especially because Small number of “superspreaders” seem to play a disproportionate role in setting the outbreaks. “About 10 to 20 percent of people are responsible for 80 to 90 percent of infections,” said Christina Ramirez, a biostatistician at the University of California, Los Angeles.
What to know about Covid-19 booster shots
FDA Authorized booster shots For a select group of people who received a second dose of the Pfizer-BioNTech vaccine at least six months ago. That group includes: Pfizer recipients who are 65 years of age or older or who live in long-term care facilities; Adults who are at high risk of severe Covid-19 because of an underlying medical condition; Health care workers and others whose jobs put them at risk. people with weak immune system Four weeks after the second shot are eligible for a third dose of Pfizer or Moderna.
The CDC states that conditions that qualify a person for a booster shot include: high blood pressure and heart disease; diabetes or obesity; cancer or blood disorder; weakened immune system; chronic lung, kidney or liver disease; Dementia and some disabilities. Pregnant women and current and former smokers are also eligible.
The FDA authorizes boosters for workers whose jobs put them at high risk of coming into contact with potentially infectious people. The CDC says the group includes: emergency medical workers; education worker; food and agricultural workers; construction workers; reform worker; US Postal Service employees; public transport workers; Grocery store workers.
It is not recommended. For now, Pfizer vaccine recipients are advised to get the Pfizer booster shot, and Moderna and Johnson & Johnson recipients should wait until a booster dose is approved from those manufacturers.
Yes. The CDC says the Covid vaccine can be administered regardless of the timing of other vaccines, and many pharmacy sites are allowing people to schedule the flu shot at the same time as a booster dose.
That means two similar communities could find themselves on fundamentally different trajectories, as a highly infectious individual happened to attend a crowded indoor event, leading to a major outbreak.
Some patterns still defy explanation. For example, in March and April, Michigan was hit hard Delta’s slightly less infectious predecessor, by alpha version.
Other states were largely spared, for reasons that are unclear, Dr. Murray said. “Why was Michigan the only state with a large alpha boom in the spring?” he said. “We have no idea.”
Scientists cautioned that it was difficult to predict what would happen next, but that cases would not necessarily continue to decline.
Britain and Israel, which have higher vaccination rates than the United States, are still grappling with outbreaks.
“This should be a wake-up call,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. “Don’t go back to the pre-Fourth of July mentality again, where everyone thought it was done and finished.”
Most experts said they would not be surprised to see at least a rise in cases this fall or later this winter as people start spending more time indoors and traveling for holidays.
But since vaccines are highly effective at preventing hospitalizations and deaths, the spikes this coming winter may be less devastating than last year.
“It is unlikely that it will be as fatal as last winter, unless we are really unlucky with respect to a newer variant,” Dr Salomon said.
The emergence of a new variant remains a wild card, as there is a possibility that the protection afforded by vaccination may be substantially reduced.
Our own behavior is another source of uncertainty.
“Predicting an outbreak is not the same as predicting the weather, because you’re dealing with human behavior,” said Nicholas Reich, a biostatistician at the University of Massachusetts, Amherst. “And it’s a fundamentally really hard thing to predict: new policies that will go into effect, people’s reactions, new trends on social media, you know — the list goes on.”
But our behavior, at least, is within our control, and it remains an important variable as we go into winter, the scientists said. Overall, he did not recommend canceling vacation plans; Many said that they themselves would celebrate with friends and relatives. But he suggested taking sensible precautions.
There’s still time to get vaccinated before Thanksgiving or to encourage loved ones to get vaccinated. Experts said wearing masks in some high-risk settings, hosting events outside when the weather is nice and conducting rapid Covid testing before holiday celebrations are all common-sense strategies to reduce risk.
“This doesn’t mean lockdown Christmas number 2,” said Angela Rasmussen, a virologist at the Vaccines and Infectious Diseases Organization at the University of Saskatchewan. “But it does mean that we all just need to be aware that it’s not quite over yet.”