Walensky said research shows the Delta variant is much more infectious. Someone with the Alpha variant — the first detected coronavirus variant — could infect two other people. With the Delta, the estimate is closer to five or more. And those carrying the Delta virus have a higher viral load, meaning they’re carrying more of the virus that could spread to others.
The Delta variant poses health risks for everyone, but the risks are significantly higher for the unvaccinated, according to new data.
- The U.S. is experiencing another spike in COVID-19 cases and hospitalizations driven by the emergence of the Delta variant.
- A large majority of new hospitalizations and deaths from COVID-19 are occurring among unvaccinated people.
- A new CDC reportTrusted Source shows that since July 26, there have been only 6,587 reports of breakthrough infections that resulted in hospitalization or death among 163 million fully vaccinated people — a percentage of 0.01 percent or less.
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub and follow our live updates page for the most recent information on the COVID-19 pandemic.
The pandemic remains a race between an increasingly infectious and changing virus and administering the vaccines, which offer high levels of protection.
At this point, 70 percent of eligible Americans have received at least one dose of a COVID-19 vaccine, while many other countries struggle to get enough vaccine supply to come anywhere near that.
While vaccine access is widespread in the United States, so is the Delta variant of the coronavirus — the one first detected in India in December. Now, a variant of that variant dubbed “Delta Plus,” an even more contagious strain, has been detected in various countries, including India, the United Kingdom, Portugal, and South Korea.
Infectious disease experts say large-scale outbreaks among unvaccinated people are being fueled by the highly contagious Delta variant.
“What makes the variant worrisome is the fact that it is a more contagious version of COVID-19 and will find unvaccinated individuals and infect them at a high rate,” Dr. Amesh A. Adalja, senior scholar at Johns Hopkins Center for Health Security, told Healthline. “If those unvaccinated are high risk for hospitalization, and there are many of them in a geographic area, it could be problematic for hospitals.”
That’s what’s occurring in places such as Arkansas, Louisiana, Texas, and Florida, where local leaders have resisted basic precautions like mask mandates and vaccination rates among young adults remain low.
Meanwhile, in the San Francisco Bay Area in California, which has some of the highest vaccine rates in the country, local authorities have reverted to mandating that people wear masks indoors in public, regardless of their vaccination status. That’s due to a spike in infections attributed to the Delta virus.
Arnab Mukherjea, chair of the Department of Public Health at California State University, East Bay, said that up to 99 percent of people experiencing severe illness from COVID-19 are unvaccinated, but no vaccine is 100 percent effective.
“There is always going to be a case where something bad happens to someone who did everything right,” Mukherjea told Healthline. “Pretty much everything we’re seeing is because of the Delta variant.”
‘A more contagious variant’
Mutations are part of a virus’ lifespan when one is given enough time and people to infect, of which SARS-CoV-2 has had many — specifically, some 200 million cases and counting.
“It was inevitable that a more contagious variant would emerge,” Adalja said. “This was evident with the Alpha variant before the Delta variant.”
During a White House press briefing Monday, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said the United States saw a 44 percent increase in the number of new cases over a 7-day period, up to 72,000 cases a day. That’s higher than the peak the United States saw last summer.
Hospital admissions and deaths were both increasing, too.
Walensky said research shows the Delta variant is much more infectious. Someone with the Alpha variant — the first detected coronavirus variant — could infect two other people. With the Delta, the estimate is closer to five or more. And those carrying the Delta virus have a higher viral load, meaning they’re carrying more of the virus that could spread to others.
The CDC said in a memo that the Delta variant is as infectious as chickenpox, a virus that was much more common before a vaccine was approved in the United States in 1995. That means Delta can spread to more people in a shorter time period, creating pockets of transmissions mostly among the unvaccinated.
“While we desperately want to be done with this pandemic, COVID-19 is clearly not done with us, and so our battle must last a little longer,” Walensky said.
That’s why the CDC now recommends everyone wear masks indoors, including children who are too young to be vaccinated but are returning to classrooms.
The vaccines and the Delta variant
While experts fear what the Delta and other variants might bring, they say there is hope because the vaccines — namely the mRNA vaccines developed by Pfizer, Moderna, and AstraZeneca — keep people from developing severe cases of COVID-19 that could lead to hospitalization or death.
In a study published in July in The New England Journal of Medicine, researchers in the United Kingdom found “only modest differences in vaccine effectiveness” in Pfizer and AstraZeneca vaccines against the Delta variant compared to the Alpha variant after a person had received two recommended doses.
Also, a new study from Imperial College London suggests that unvaccinated people are three times more likely than those who are fully vaccinated to test positive for COVID-19. Researchers also said fully vaccinated people are less likely to transmit the virus to others.
That’s good news for vaccinated people looking to safely gather with other vaccinated people who don’t live together.
Walensky said that there’s generally less severe disease in places where more people are vaccinated, even in breakthrough infections, which occur among people fully vaccinated against COVID-19.
“While vaccinated people can spread the virus if they get a breakthrough infection, the odds of them getting sick in the first place are far lower than those who are unvaccinated,” she explained.
At that meeting, Dr. Anthony Fauci, the nation’s leading infectious disease expert, reminded reporters that breakthrough infections are “expected and usually asymptomatic.”
A new CDC reportTrusted Source shows that since July 26, there have been only 6,587 reports of breakthrough infections that resulted in hospitalization or death among 163 million fully vaccinated people.
“That is a percentage of 0.01 percent or less,” Fauci said. “The bottom line is they are rare, and they rarely result — not rarely, but unusually result in hospitalization or death.”
Again, Fauci reminded everyone: Get vaccinated.
“The COVID vaccines give strong protection against the Delta variant, and it protects you, your family, and your community,” he said.
While experts are concerned that even more powerful and infectious variants could emerge before the pandemic ends, they’re worried about the havoc the Delta variant could bring.
As the Delta variant continues to spread, one big fear is that hospital systems may again become overwhelmed and be unable to treat all patients fully. This is why efforts to encourage people to get vaccinated or, at least, get tested if they’re showing symptoms are being increased.
But public health officials want, above anything else, for everyone who can to get vaccinated.
“The goal is to limit the damage that these variants cause by protecting high-risk individuals through vaccination,” Adalja said.
There’s always going to be a baseline of cases, but the vaccine greatly reduces the severity of those cases, Adalja said. Reinstituting mask orders — particularly among fully vaccinated — won’t have much impact overall, he said.
“Mask wearing by the vaccinated is not going to have a significant role in the subject of the pandemic, as it is being driven by the unvaccinated,” he said.