What the Delta variant could mean for Covid-19 in the United States

(CNN)A coronavirus variant first spotted in India is poised to become the dominant one in the United States, where infectious disease modelers say it could cause a “resurgence” of Covid-19 later this year.

And it may already account for 1 in every 5 infections nationwide, experts say.
The Delta variant, as it’s now called, has swept across the UK, all but replacing the Alpha variant first identified there late last year.
“This is the most transmissible of all the variants that we’ve seen,” Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told CNN’s Ana Cabrera Monday.
“We saw what happened in the UK, where it overtook the entire nation. So I’m worried that’s going to happen in the US,” he said.
Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention, told CNN last week she anticipates Delta will become “the predominant variant in the months ahead.”
And that could be a few weeks — not months — away, according to William Lee, vice president of science at Helix, a company whose Covid-19 tests have helped track a number of variants.
In the two weeks leading up to June 5, CDC estimates that Delta was responsible for nearly 10% of US infections. And now, Hotez, Lee, and the nation’s top infectious disease physician, Dr. Anthony Fauci, say it accounts for roughly a fifth of cases.
“As of a couple of days ago, 20.6% of the isolates are Delta,” Fauci said at a White House briefing Tuesday, referring to the two weeks leading up to June 19. This number has roughly doubled every two weeks, he added.
“It’s so transmissible that, unless your vaccination rates are high enough, you will still have outbreaks,” said Lee.
A more transmissible variant like Delta also raises the bar for what percent of a population has to be vaccinated “to reach this mythical herd immunity,” he explained.
“More worrisome is that we know that there are pockets of unvaccinated people,” he added. “And so I would be worried about Delta spreading very quickly in those pockets.”

Predicting the future

Infectious disease modelers are showing how a variant like Delta could make a Covid-19 comeback later this year.
Faced with a more transmissible variant, “it looks like we do see a resurgence late in the summer, or in the early fall,” said Justin Lessler, an epidemiologist with the Johns Hopkins Bloomberg School of Public Health.
Lessler has been working with contributors from a dozen other institutions on the Covid-19 Scenario Modeling Hub to forecast the pandemic.

The most recent model finds that a Delta-like variant that’s assumed to be 60% more transmissible than Alpha, coupled with 75% of eligible Americans getting vaccinated, can result in Covid-19 bouncing back from summer lows to cause more than 3,000 deaths per week at various points during the fall and winter — coinciding with children returning to school and weather that pushes people back indoors.
That’s about 1,000 more Covid-19 deaths than the US has seen over the past week, though still far below the peak of 24,000 deaths during the second week of January.
But according to the model, getting 86% of eligible Americans vaccinated — meaning, those 12 and up — could avert more than 10,000 cumulative deaths by late November.
Currently, 62.5% of Americans 12 and up have gotten at least one dose of a vaccine, according to CDC. At the current pace, the country would hit 75% in September and 86% in November. However, the pace of vaccination has slowed in recent weeks.
Lessler said that Covid-19 resurgences wouldn’t be experienced uniformly all over the country: “It’s the states that have lower vaccination rates, and a lower projected vaccination rate, that are really driving those resurgences.”
At the White House briefing Tuesday, Fauci called Delta the country’s “greatest threat” in its fight against the coronavirus.
But it’s a preventable threat, he added, and one that’s unlikely to reach the level of earlier peaks. Instead, “you could see localized surges,” he said. “All of that is totally and completely avoidable by getting vaccinated.”
Research on Delta in the UK has shown high levels of protection from two doses of the vaccines used there, with effectiveness against hospitalization exceeding 90% for both Delta and Alpha, according to Public Health England.
Dr. David Rubin, director of PolicyLab at Children’s Hospital of Philadelphia, has also seen trends of increasing cases, hospitalizations and deaths in areas of lower vaccination.
Rubin said his team is increasingly focused on hospitalizations and emergency room data to see how the pandemic plays out because, as fewer people get tested, the number of cases is becoming a less reliable marker.
In areas with lower vaccination rates, they noted a slower rate of decline in hospitalizations. Rubin pointed to the state of New York, where about 52% of the population is fully vaccinated, and where the rate of new hospital admissions has been steadily declining. Meanwhile, in a state like Missouri, where just 38% are fully vaccinated, the hospitalization rate is not only higher but has shown an increasing trend since mid-May, according to CDC data.
While it may feel like the country has turned a corner, Rubin warned “the pandemic hasn’t ended.”
Polls such as the Kaiser Family Foundation’s have shown that about 1 in 5 adults say they won’t get vaccinated, or will only do so if required. But that number is higher among certain groups — like Republicans, White evangelical Christians, younger age groups and people who live in rural areas.

Delta’s trajectory in the US

While experts agree that Delta poses a greater threat to unvaccinated populations, it’s not a foregone conclusion it will follow the exact same trajectory in the US as it did in the UK, Helix’s Lee said.
In a preprint that has not yet been peer-reviewed, Lee and his colleagues describe how the US outbreak has unfolded somewhat differently:
In the US, Covid-19 cases caused by the Alpha variant (also known as B.1.1.7) grew to 70% in April but plateaued there — at a much lower level than it did in the UK.
It’s hard to know exactly why, Lee said. It may have something to do with the diverse set of policies that could impact the spread of the virus — including public health measures and the vaccine rollout in the US.
Even so, from late April to mid-June, the Alpha variant fell from 70% to 42% of Covid-19 cases. And it’s not just Delta that appears to be responsible, but also another variant of concern found in Brazil  — known as P.1 or Gamma.

Black People – More likely to die in traffic accidents

Experts say this is not new. Even though Americans drove less in the pandemic. More Black people died in traffic deaths in 2020 than any other racial group.

Black people represented the largest increase in traffic deaths last year than any other racial group, even as Americans drove less overall due to the pandemic, according to recently released data.

An estimated 38,680 people died in motor vehicle traffic crashes in 2020 — the largest projected number of deaths since 2007, according the U.S. Department of Transportation’s National Highway Traffic Safety Administration. The number of Black people who died in such crashes was up 23 percent from 2019, the largest increase in traffic deaths among racial groups, according to the administration’s report.

Norman Garrick, a civil and environmental engineering professor at the University of Connecticut, said the numbers are saddening, but not surprising.

“Black people tend to be overrepresented as walkers in this country,” Garrick said. “This is not by choice. In many cases, Black folks cannot afford motor vehicles. And people that walk in this country tend to experience a much, much higher rate of traffic fatality. We’re talking eight to 10 times more. It’s a perfect storm of a lot of horrible forces.”

This most likely represents yet another way the health crisis has had an outsize effect on Black people. Even in the early days of the pandemic, the National Safety Council found that the emptier roads were proving to be more deadly, with a 14 percent jump in roadway deaths per miles driven in March. And Black people are more likely to face traffic injuries in general; from 2010-2019, Black pedestrians were 82 percent more likely to be hit by drivers, according to a 2021 report from Smart Growth America, a Washington, D.C.-based advocacy group focused on urban development.

Calvin Gladney, president of Smart Growth America, said the pandemic has only exacerbated the longstanding problem. He said there are three major reasons Black people bear the brunt of roadway injuries: infrastructure, design and racism. Predominantly Black neighborhoods are less likely to have crosswalks, warning signs and other safety mechanisms, he said. And many high-speed highways are in or go through communities of color, thanks to a federal effort in the 1950s to modernize the nation’s roadways.

“These fatalities have been going upward for a decade,” Gladney said. “You go to Black and brown communities, you go to lower-income communities and you don’t see many sidewalks. You don’t see as many pedestrian crossings. The types of streets that go through Black and brown neighborhoods are like mini highways where the speed limit is 35 or 45. You see this disproportionately in Black and brown communities often because of race-based decisions of the past.”

Little to no infrastructure funding means those in Black neighborhoods live with poor roads, dangerous proximity to waste sites, little access to public transportation and more. Along with the systemic nature of this problem, Gladney pointed out that social racism also plays a role in the rising number of traffic fatalities. A 2017 study from the University of Nevada found that drivers are less likely to slow down or stop for Black pedestrians than they are for white ones.

Gladney said that efforts like President Joe Biden’s proposed $2 trillion American Jobs Plan, which includes efforts to make public transportation more accessible and improve road safety, are necessary, and that although the situation is dire “it’s fixable.”

He said small policy changes like lowering the speed limit in some areas could save hundreds of lives each year. Federal efforts like the 2021 Complete Streets Act — introduced by Rep. Steve Cohen, D-Tenn. — would ensure public roads are safe and accessible for multiple modes of travel.

“The pandemic illuminated issues that people have been ignoring,” Gladney added. “These are the same streets and the same roads that have always been there. If we have intentionality to get to racial equity and close the disparities, we actually can fix this.”