What to Know about the Fast-Spreading Delta Variant
A highly contagious form of the coronavirus known as the Delta variant is spreading rapidly and becoming increasingly prevalent around the world. First identified in India in December, Delta has now been identified in 111 countries.
In the United States, the variant now accounts for 83% of sequenced COVID-19 cases, said Rochelle Walensky, director of the Centers for Disease Control and Prevention, at a July 20 Senate hearing. In May, Delta was responsible for just 3% of U.S. cases. The World Health Organization projects that Delta will become the dominant variant globally over the coming months.
So, how worried should you be about the Delta variant? We asked experts some common questions about Delta.
What is a variant?
To understand Delta, it's helpful to first understand what a variant is. When a virus infects a person, it gets into your cells and makes a copy of its genome so it can replicate and spread throughout your body.
In the process of making new copies of itself, the virus can make a mistake in its genetic code. Because viruses are replicating all the time, these mistakes — also called mutations — happen pretty often. A new variant emerges when a virus acquires one or more new mutations and starts spreading within a population.
There are thousands of SARS-CoV-2 variants, but most of them don't substantially change the way the virus behaves. The variants that scientists are most interested in are known as variants of concern. These are versions of the virus with mutations that allow the virus to spread more easily, evade vaccines, or cause more severe disease.
"The vast majority of the mutations that have accumulated in SARS-CoV-2 don't change the biology as far as we're concerned," said Jennifer Surtees, a biochemist at the University of Buffalo who's studying the coronavirus. "But there have been a handful of key mutations and combinations of mutations that have led to what we're now calling variants of concern."
One of those variants of concern is Delta, which is now driving many new COVID-19 infections.
Why is the Delta variant so concerning?
"The reason why the Delta variant is concerning is because it's causing an increase in transmission," said Alba Grifoni, an infectious disease researcher at the La Jolla Institute for Immunology. "The virus is spreading faster and people — particularly those who are not vaccinated yet — are more prone to exposure."
The Delta variant has a few key mutations that make it better at attaching to our cells and evading the neutralizing antibodies in our immune system. These mutations have changed the virus enough to make it more than twice as contagious as the original SARS-CoV-2 virus that emerged in Wuhan and about 50% more contagious than the Alpha variant, previously known as B.1.1.7, or the U.K. variant.
These mutations were previously seen in other variants on their own, but it's their combination that makes Delta so much more infectious.
Do vaccines work against the Delta variant?
The good news is, the COVID-19 vaccines made by AstraZeneca, Johnson & Johnson, Moderna, and Pfizer still work against the Delta variant. They remain more than 90% effective at preventing hospitalizations and death due to Delta. While they're slightly less protective against disease symptoms, they're still very effective at preventing severe illness caused by the Delta variant.
"They're not as good as they were against the prior strains, but they're holding up pretty well," said Eric Topol, a physician and director of the Scripps Translational Research Institute, during a July 19 briefing for journalists.
Because Delta is better at evading our immune systems, it's likely causing more breakthrough infections — COVID-19 cases in people who are vaccinated. However, breakthrough infections were expected before the Delta variant became widespread. No vaccine is 100% effective, so breakthrough infections can happen with other vaccines as well. Experts say the COVID-19 vaccines are still working as expected, even if breakthrough infections occur. The majority of these infections are asymptomatic or cause only mild symptoms.
Should vaccinated people worry about the Delta variant?
Vaccines train our immune systems to protect us against infection. They do this by spurring the production of antibodies, which stick around in our bodies to help fight off a particular pathogen in case we ever come into contact with it.
But even if the new Delta variant slips past our neutralizing antibodies, there's another component of our immune system that can help overtake the virus: T cells. Studies are showing that the COVID-19 vaccines also galvanize T cells, which help limit disease severity in people who have been vaccinated.
"While antibodies block the virus and prevent the virus from infecting cells, T cells are able to attack cells that have already been infected," Grifoni said. In other words, T cells can prevent the infection from spreading to more places in the body. A study published July 1 by Grifoni and her colleagues found that T cells were still able to recognize mutated forms of the virus — further evidence that our current vaccines are effective against Delta.
Can fully vaccinated people spread the Delta variant?
Previously, scientists believed it was unlikely for fully vaccinated individuals with asymptomatic infections to spread Covid-19. But the Delta variant causes the virus to make so many more copies of itself inside the body, and high viral loads have been found in the respiratory tracts of people who are fully vaccinated. This suggests that vaccinated people may be able to spread the Delta variant to some degree.
If you have COVID-19 symptoms, even if you're fully vaccinated, you should get tested and isolate from friends and family because you could spread the virus.
What risk does Delta pose to unvaccinated people?
The Delta variant is behind a surge in cases in communities with low vaccination rates, and unvaccinated Americans currently account for 97% of hospitalizations due to COVID-19, according to Walensky. The best thing you can do right now to prevent yourself from getting sick is to get vaccinated.
Gigi Gronvall, an immunologist and senior scholar at the Johns Hopkins Center for Health Security, said in this week's "Making Sense of Science" podcast that it's especially important to get all required doses of the vaccine in order to have the best protection against the Delta variant. "Even if it's been more than the allotted time that you were told to come back and get the second, there's no time like the present," she said.
With more than 3.6 billion COVID-19 doses administered globally, the vaccines have been shown to be incredibly safe. Serious adverse effects are rare, although scientists continue to monitor for them.
Being vaccinated also helps prevent the emergence of new and potentially more dangerous variants. Viruses need to infect people in order to replicate, and variants emerge because the virus continues to infect more people. More infections create more opportunities for the virus to acquire new mutations.
Surtees and others worry about a scenario in which a new variant emerges that's even more transmissible or resistant to vaccines. "This is our window of opportunity to try to get as many people vaccinated as possible and get people protected so that so that the virus doesn't evolve to be even better at infecting people," she said.
Does Delta cause more severe disease?
While hospitalizations and deaths from COVID-19 are increasing again, it's not yet clear whether Delta causes more severe illness than previous strains.
How can we protect unvaccinated children from the Delta variant?
With children 12 and under not yet eligible for the COVID-19 vaccine, kids are especially vulnerable to the Delta variant. One way to protect unvaccinated children is for parents and other close family members to get vaccinated.
It's also a good idea to keep masks handy when going out in public places. Due to risk Delta poses, the American Academy of Pediatrics issued new guidelines July 19 recommending that all staff and students over age 2 wear face masks in school this fall, even if they have been vaccinated.
Parents should also avoid taking their unvaccinated children to crowded, indoor locations and make sure their kids are practicing good hand-washing hygiene. For children younger than 2, limit visits with friends and family members who are unvaccinated or whose vaccination status is unknown and keep up social distancing practices while in public.
While there's no evidence yet that Delta increases disease severity in children, parents should be mindful that in some rare cases, kids can get a severe form of the disease.
"We're seeing more children getting sick and we're seeing some of them get very sick," Surtees said. "Those children can then pass on the virus to other individuals, including people who are immunocompromised or unvaccinated."
New tech helps people of all ages stay social
In March, Sonja Bauman, 39, used an online platform called Papa, which offers “family on demand,” to meet Mariela Florez, an 83-year-old retiree. Despite living with her adult children, Florez was bored and lonely when they left for work, and her recoveries from a stroke and broken hip were going slowly. That's when Bauman began visiting twice per week. They take walks, strengthening Florez’s hip, and play games like Connect Four for mental stimulation. “It’s very important for me so I don’t feel lonely all day long,” said Florez. Her memories, blurred by the stroke, are gradually returning.
Papa is one of a growing number of tech approaches that are bringing together people of all ages. In addition to platforms like Papa that connect people in real life, other startups use virtual reality and video, with some of them focusing especially on deepening social connections between the generations — relationships that support the health of older and younger people alike. “I enjoy seeing Mariela as much as she enjoys seeing me,” Bauman said.
Connecting in real life
Telehealth expert Andrew Parker founded Papa in 2017 to improve the health outcomes of older adults and families. Seniors can meet people — some their grandkids’ age — for healthy activities, while working parents find retirees to watch their children. These “Papa Pals” are provided as a benefit through Medicare, Medicaid and some employer health plans.
In 2020, Papa connected Bauman, the 39-year-old Floridian, with another woman in her mid-70s who lives alone and has very limited mobility. Bauman began driving her to doctor’s appointments and helping her with chores around the house. “When I’m not there, she doesn’t leave her apartment,” said Bauman. The two have gone to the gym together, and they walk slowly through the neighborhood, chatting so it feels less like exercise.
Parker was driven to start Papa by the problem of social isolation among seniors, exacerbated by the pandemic, but he believes users of all ages can benefit. “Many of our Pals feel more comfortable opening up with older members than their same-aged friends,” he said.
Other platforms aim for similar, in-person connections. Generation Tech unites teens with seniors for technology training. And Mon Ami, which provides case management software for aging and disability service providers, has an app that connects isolated older people with college-age volunteers.
Making new connections through video
Several new sites match you with strangers for real-time video chatting on various topics, such as finding common ground on political issues. Other video platforms focus on intergenerational connections.
S. Jay Olshansky, a gerontology professor at the University of Illinois-Chicago, recalls the first time he saw Hyunseung Lee, an 11-year-old from Seoul, through his computer screen. The kid was shy, but Olshansky, 67, encouraged him to ask questions. “Turns out, he was thirsting for this kind of interaction.”
They’d connected through Eldera, a platform that pairs mentors age 60 and up with mentees, using an algorithm, for video conversations. “The time and wisdom of older adults is the most important natural resource we can give future generations,” said Dana Griffin, Eldera's CEO. “Connecting through a screen is the opposite of social media.”
In weekly meetings, Olshansky noticed Lee’s unique interest in math. “There’s something special in you,” Olshansky told him. “How do we bring it to the surface?” He suggested Lee write a book on his favorite subject, and the preteen ran with it, cranking out 70 pages in two weeks. Lee has published his love letter to theorems on Amazon.
Hyunseung Lee, age 11, of Korea, and U.S. college professor Jay Olshanksy, 67, discuss math, strategy and Hyunsung's budding career as a book author during their video chats through a platform called Eldera. (Photo by Dana Palmer/Eldera)
Lee’s parents told Olshansky that their son has become more assertive — a recurring theme, Griffin said. “Confidence is the number one thing parents tell us about.” Since Eldera’s inception last year, the number of mentors has grown exponentially. Even so, Griffin said the waitlist for mentors typically numbers 200 kids.
Another site, Big and Mini, hosts video interactions between seniors and young adults; about 10,000 active users have joined since 2019, said co-founder Aditi Merchant.
Users often bring the benefits of their video interactions to their real-world relationships. Olshansky views Lee as an older version of his grandkids. “Eldera teaches me how to interact with them.” Lee, high on confidence, began instructing his classmates in math. Griffin noted that a group of Eldera mentors in Memphis, who met initially on Eldera, now take walks together in-person to trade ideas for helping each other’s Eldera kids solve problems in their schools and communities.
“We’ve evolved into a community for older adults who want to give back to the world,” said Griffin. Other new tools for connection take the form of virtual reality apps.
Connecting in virtual reality
During pandemic isolation, record numbers of people bought devices for virtual and augmented reality. Such gadgets can convince you that you’re hanging out with friends, even if they’re in another hemisphere. Lifelike simulations from miles away could be especially useful for meaningful interactions between people of different generations, since they’re often geographically segregated.
VR’s benefits require further study, but users report less social isolation and depression, according to MIT research. The immersive, 3-D experience is more compelling than FaceTime or Zoom. “It’s like the difference between a phone call and video call,” said Rick Robinson, Vice President of AARP’s Innovation Labs.
“When VR is designed right, the medium disappears,” said Jeremy Bailenson of Stanford.
Dana Pierce, a 56-year-old government employee in Indiana, got Meta's VR headset in May, 2021, thinking she’d enjoy it more than a new laptop. After many virtual group tours of exotic destinations, she has no regrets. Her adventures occur on Alcove, an app made by Robinson’s Innovation Labs. He co-created it with VR-company Rendever and sought input from people over age 50 to tailor it to their interests. “I’m an introvert,” said Pierce. “I’ve been more socially active since getting my headset than I am in real life.”
Tagging along with her to places like Paris are avatars representing real people around the world. She’s gotten to know VR users in their 70s, 80s and 90s, as well as younger people and some her own age. One is a new friend she plays chess with in relaxing nature settings. Another is her oldest son. He lives 90 minutes away but, earlier this year, Pierce welcomed him and his girlfriend to her virtual house on Alcove. They chatted in the living room decorated with family photos uploaded by Pierce. Then they took out a boat to go VR fishing — because why not — until 2 a.m.
“When VR is designed right, the medium disappears,” said Jeremy Bailenson, a communications professor who directs Stanford’s Virtual Human Interaction Lab. He’s teaching a class of 175 students entirely in VR. After months of covid isolation, the first time the class met, “there was a big catharsis. It really feels like you’re in a big crowd.” Like-minded people meet in VR for events such as comedy shows and creative writing meetups, while the Swedish pop group ABBA has performed this year as digital versions of themselves (“ABBA-tars”) during a virtual concert tour.
Karen Fingerman, a psychologist and director of the Texas Aging and Longevity Center at the University of Texas-Austin, supports the idea of VR for social connection, though she added that some people need it more than others. Hospitals and assisted-living facilities are using products such as Penumbra’s REAL I-Series and MyndVR to bring VR excursions to isolated patients and seniors. “If you’re in a bed or facility, this gives you something to talk about,” said Gita Barry, Penumbra’s executive vice president.
Pierce uses it on most days. She may see another adult son, who lives with her, less often as a result. But VR helps her manage real-world stressors, more than escaping them. After a long workday, she visits her back porch on Alcove, which overlooks a pond. “It’s my little retreat,” she said. “VR improves my mood. It’s added a lot to my life.”
Some seniors are using more than one technology. Olshansky and Lee discuss strategy while playing Internet chess. And Olshansky recently began using VR. He sees his sister, who lives far away, in a virtual beach house. “It’d be a great way to interact with Hyunseung,” he said. “I should get him a headset.”
A version of this article first appeared in The Washington Post on December 3, 2021.
Friday Five: These boots were made for walking, even for people who can't
The Friday Five covers important stories in health and science research that you may have missed - usually over the previous week but, today, we're doing a lookback on breakthrough research over the month of October. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
This Friday Five episode covers the following studies published and announced over the past month:
- New boots could have you moving like Iron Man
- The problem with bedtime munching
- The perfect recipe for tiny brains
- The best sports for kids to avoid lifelong health risks
- Can virtual reality reduce pain?