US Covid-19 cases rise as Delta variant spreads

By Meg Wagner, Melissa Macaya, Melissa Mahtani, Veronica Rocha and Fernando Alfonso III, CNN

Updated 8:03 p.m. ET, July 30, 2021
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2:10 p.m. ET, July 30, 2021

CNN's Sanjay Gupta says CDC study shows Delta variant is "really contagious," but vaccines work

CNN's chief medical correspondent Sanjay Gupta broke down the US Centers for Disease Control and Prevention's new study about the Delta Covid-19 variant spread— and what its findings could mean for vaccinated and unvaccinated Americans across the country.

"The idea that people who were vaccinated still were far less likely to develop severe symptoms, hospitalizations, deaths, all the things that we've talked about since the vaccines were first authorized, remain true. The vaccines work, in that regard, but the idea that someone [who is vaccinated] could test positive and still develop enough virus in their nose and mouth to transmit is really what this data is showing," Gupta told CNN's Ana Cabrera following the release of the study. 

The study, published by CDC Friday, describes 469 Massachusetts residents who were infected in a July outbreak in Barnstable County, which includes the summer vacation destination Provincetown. No deaths were reported among them.

About 74% — or 346 cases —had been fully vaccinated. Of those cases, 79% reported symptoms. Genetically sequenced cases revealed the Delta variant as the main culprit.

"I still want to reiterate just how effective the vaccines can be at doing the things that people I think looked for them to do the most. Prevent severe hospitalization and death. But it is clear that this Delta variant is far more transmissible and as a result of that, probably even vaccinated people are transmitting this at a higher rate than we thought," Gupta said.

In terms of what comes next, Gupta said this study will likely spark new questions about preventative measures, including masking and when Americans may need a booster shot.

"They're saying this is really, really contagious. So even if there's not a lot of viral transmission now, it's likely to increase, because of the contagiousness of this and also because we're going into cooler and dryer weather where we know virus tend to transmit more easily anyway," Gupta said. "So, I think there's going to be some changes that come about here, with regard to those recommendations, both on boosters and masking, you know, throughout the country."

On Tuesday, Walensky previewed these findings while unveiling guidance that people in areas with "high" or "substantial" Covid-19 transmission should resume wearing masks indoors. Over 75% of the US population live in these areas.

Here's a look at some of the key findings of the study:

Read more about the CDC study here.

CNN's Michael Nedelman contributed reporting to this post.

1:16 p.m. ET, July 30, 2021

CDC report shows 90% of vaccine side effects in adolescents are non-serious

From CNN's Jacqueline Howard

Registered nurse Sue Dillon explains the vaccination process to a student before administering a dose of the Pfizer vaccine at a three-day vaccination clinic on July 29, in Wilmington, California.
Registered nurse Sue Dillon explains the vaccination process to a student before administering a dose of the Pfizer vaccine at a three-day vaccination clinic on July 29, in Wilmington, California. Mario Tama/Getty Images

Among millions of adolescents who have received the Pfizer/BioNTech coronavirus vaccine, new data show that most of those who have reported side effects experienced non-serious conditions – and the heart condition myocarditis was listed among 4.3% of all reports. 

Data published Friday by the US Centers for Disease Control and Prevention finds that among 8.9 million adolescents vaccinated between December and July, reports of adverse events were received for about 1 per 1,000 vaccines. 

Overall, 8,383 or 90.7% of reports were for non-serious events and 9.3% were for serious events, including death. No reports of death were determined to be the result of myocarditis.

Among the rare serious reports only, the most common were: chest pain at 56.4%; increased troponin, which can indicate a problem with the heart, at 41.7%; and myocarditis, or inflammation of the heart muscle, at 40.3%, according to the report.

Some more background: Beginning in June, reported cases of myocarditis emerged among young people after receiving the vaccine, primarily among boys. Later that month, the US Food and Drug Administration added a warning to the fact sheets for the Moderna and Pfizer/BioNTech coronavirus vaccines.

CDC researchers wrote in the new data that, as of July 16, the federal government's Vaccine Adverse Event Reporting System, or VAERS, received 9,246 reports among 12- to 17-year-olds after receiving the Pfizer/BioNTech vaccine, out of about 8.9 million adolescents vaccinated. The VAERS surveillance system relies on people to submit reports and might not be generalizable to the overall vaccinated population. Common conditions reported were dizziness, temporary loss of consciousness and headache.

"The findings summarized in this report are consistent with the safety data observed in preauthorization trials for Pfizer- BioNTech after vaccination among persons aged 12–25 years, with the exception of myocarditis, a serious adverse event detected in postauthorization safety monitoring," CDC researchers wrote in the report.

"Local and systemic reactions after vaccination with Pfizer-BioNTech vaccine were commonly reported by adolescents aged 12–17 years to U.S. vaccine safety monitoring systems, especially after dose 2," the researchers wrote. "A small proportion of these reactions are consistent with myocarditis."

1:14 p.m. ET, July 30, 2021

CDC shares "pivotal discovery" on Covid-19 breakthrough infections that led to new mask guidance

From CNN's Michael Nedelman

A woman wears a mask in Midtown Manhattan in New York on July 29.
A woman wears a mask in Midtown Manhattan in New York on July 29. Kena Betancur/AFP/Getty Images

A new study shows the Delta coronavirus variant produced similar amounts of virus in vaccinated and unvaccinated people if they get infected – illustrating a key motivation behind the federal guidance that now recommends most fully vaccinated Americans wear masks indoors.

Experts say that vaccination makes it less likely that you'll catch Covid-19 in the first place – but for those who do, this data suggests they could have a similar tendency to spread it as unvaccinated people.

"High viral loads suggest an increased risk of transmission and raised concern that, unlike with other variants, vaccinated people infected with Delta can transmit the virus," Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention, said in a statement Friday.

The study, published by CDC Friday, describes 469 Massachusetts residents who were infected in a July outbreak in Barnstable County, which includes the summer vacation destination Provincetown. No deaths were reported among them. 

About 74% — or 346 cases — had been fully vaccinated. Of those cases, 79% reported symptoms. Genetically sequenced cases revealed the Delta variant as the main culprit.

The researchers found evidence that viral loads were similar among 127 fully vaccinated people and 84 others who were unvaccinated, partially vaccinated or whose vaccination status was unknown. Viral load is a proxy for how likely someone might be to transmit the virus to others.

The finding that the Delta variant resulted in similar viral loads "was a pivotal discovery leading to CDC's updated mask recommendation," Walensky said Friday.

On Tuesday, Walensky previewed these findings while unveiling guidance that people in areas with "high" or "substantial" Covid-19 transmission should resume wearing masks indoors. More than 75% of the US population live in these areas.

Although these findings motivated CDC to update its guidance, the study notes that Barnstable County was not one of those areas until the outbreak. Between July 3 and 17, daily new cases rose from a 14-day average of 0 to 177 cases per 100,000 residents.

The study suggests that "even jurisdictions without substantial or high COVID-19 transmission might consider expanding prevention strategies, including masking in indoor public settings regardless of vaccination status."

CNN previously reported on the outbreak connected to Provincetown. In total, at least 882 cases have been linked to the cluster so far – about 60% of whom were Massachusetts residents, according to local officials.

A source familiar with the CDC's decision to update its recommendations previously told CNN that, in addition to the viral load findings, the overall prevalence of Delta and lower-than-hoped vaccine uptake played key roles in the latest iteration of the guidance.

12:49 p.m. ET, July 30, 2021

A CDC document warns the Delta variant appears to spread like chickenpox. Here's what that looks like. 

From CNN's Paul LeBlanc, Maggie Fox and Elizabeth Cohen

The Delta coronavirus variant surging across the United States appears to cause more severe illness and spread as easily as chickenpox, according to an internal document from the US Centers for Disease Control and Prevention.

The document — a slide presentation — outlines unpublished data that shows fully vaccinated people might spread the Delta variant at the same rate as unvaccinated people.

CDC Director Dr. Rochelle Walensky confirmed the authenticity of the document, which was first reported by The Washington Post.

The CDC is scheduled to publish data today that will back Walensky's controversial decision to change guidance for fully vaccinated people. 

The Delta variant's comparison to the chickenpox has prompted questions about how easily it can spread within a group of people.

Here's a look at how the Delta variant's spread compares to the early Covid-19 strain, according the CDC:

12:37 p.m. ET, July 30, 2021

The latest data on the Covid-19 pandemic in the US, in 3 charts

As the Delta variant continues to spread in the US, 49 states are seeing a surge in cases. Some experts say stricter vaccine mandates may be the best way to prevent a full downward spiral.

Cases and hospitalizations are climbing across much of the US, although numbers are not anywhere near the peaks the country say in January. Deaths have also increased in parts of the country following steady declines.

Here's a look at how Covid-19 data has progressed since the start of the pandemic in the US:

11:10 a.m. ET, July 30, 2021

Daily Covid-19 cases similar to this time last year, but rising rapidly instead of falling, JHU data shows

From CNN's Deidre McPhillips

Registered nurse Darryl Hana prepares a dose of the Pfizer vaccine at a three-day vaccination clinic at Providence Wilmington Wellness and Activity Center on July 29, in Wilmington, California.
Registered nurse Darryl Hana prepares a dose of the Pfizer vaccine at a three-day vaccination clinic at Providence Wilmington Wellness and Activity Center on July 29, in Wilmington, California. Mario Tama/Getty Images

Nationwide, there are about the same number of new Covid-19 cases reported each day as there were at this time last year, but they’re rising quickly right now instead of falling as they were last year, according to a CNN analysis of data from Johns Hopkins University.

The United States recorded an average of about 67,000 new Covid-19 cases each day over the past week, compared to an average of more than 65,000 cases each day in the last week of July 2020.

But at this time last year, cases were on the decline, dropping below 50,000 cases per day about halfway into August 2020. Most recently, average daily cases have been rising for more than three weeks straight. 

While cases are trending up, average daily Covid-19 deaths in the US are a fraction of what they were a year ago. About 305 people died of Covid-19 each day over the most recent seven days, but more than 1,000 people were dying of Covid-19 each day at this time last year, according to JHU data.

 You can track Covid-19 cases in the US here.

10:39 a.m. ET, July 30, 2021

New York City's Broadway theaters will require vaccinations for audience and staff

From CNN's Kwegyirba Croffie

A person without a mask shows their Covid-19 vaccination card before entering "Springsteen on Broadway" at the St. James Theatre in Times Square on July 10, in New York City.
A person without a mask shows their Covid-19 vaccination card before entering "Springsteen on Broadway" at the St. James Theatre in Times Square on July 10, in New York City. Alexi Rosenfeld/Getty Images

Owners and operators of all 41 Broadway theaters in New York City will require audience members and performers as well as staff to be vaccinated for all performances through the month of October, the Broadway League announced Friday.

Masks will also be required for audiences inside theaters, except for when they are eating or drinking in designated locations, the release said. 

Under the joint policy, guests will need to be fully vaccinated with an US Food and Drug Administration or World Health Organization authorized vaccine in order to attend and must show proof upon entry, the release stated.

Exceptions, they said, are being made for children under the age of 12, as well as those with a medical condition or religious belief preventing vaccination.  

10:43 a.m. ET, July 30, 2021

Louisiana doctor says his hospital is admitting 1 Covid-19 patient per hour as Delta brings rise in cases

From CNN's Adrienne Vogt

CNN
CNN

A critical care physician in Louisiana has a stark warning for unvaccinated individuals:

“You cannot avoid Delta. It is not possible. So you have a decision — and the decision is get vaccinated or not. And the results are telling us, if you're not vaccinated, you have a really poor outcome. If you look at our ICU patients this morning, 97% are unvaccinated and the average age is 48,” Dr. Christopher Thomas of Our Lady of the Lake Regional Medical Center in Baton Rouge told CNN’s Poppy Harlow. 

He said the number of Covid-19 patients is affecting health care as a whole. 

“We’re becoming victims of the unvaccinated at the current pace. We currently are overwhelming our bed capacity. We're creating burnout for our teams. And honestly, we're beginning to impact the rest of the health care of the community,” he said. 

Thomas said his hospital currently has more than 50 patients in intensive care units, with 18 patients holding in its emergency department. There is also a shortage of nursing, he said.  

“We're admitting one Covid patient alone per hour. So one per hour. That means that the other patients who need care are being impacted. We are looking over the cliff. I don't see an end in sight,” he said. 

Watch:

9:59 a.m. ET, July 30, 2021

A leaked CDC document shows new data on the Delta variant's spread. Here are key things to know.

From CNN's Elizabeth Cohen and Ben Tinker

 Fin Gomez, a journalist with CBS News and White House Correspondents Association board member, replaces signs for mask-wearing guidance around the James Brady Press Briefing Room at the White House on July 27, in Washington, DC.
 Fin Gomez, a journalist with CBS News and White House Correspondents Association board member, replaces signs for mask-wearing guidance around the James Brady Press Briefing Room at the White House on July 27, in Washington, DC. Anna Moneymaker/Getty Images

An internal report presented to the US Centers for Disease Control and Prevention indicates the Delta coronavirus variant is far more transmissible than older lineages, may cause more severe disease, and that when it causes breakthrough infections, may be as easily transmitted as when it infects unvaccinated people.

What the document shows:

  • The slideshow dated Thursday and first obtained by The Washington Post, appears to provide some data backing CDC Director Dr. Rochelle Walensky’s controversial decision on Tuesday to change the agency’s guidance on mask use.
  • It says the Delta variant is about as transmissible as chickenpox, with each infected person, on average, infecting eight or nine others. The original lineage was about as transmissible as the common cold, with each infected person passing the virus to about two other people on average.
  • And if vaccinated people get infected anyway, they have as much virus in their bodies as unvaccinated people. But vaccinated people are safer, the document indicates. It says vaccines reduce the risk of severe disease or death 10-fold and reduce the risk of infection three-fold.
  • The CDC, the document advises, should “acknowledge the war has changed.” It recommends vaccine mandates and universal mask requirements.

How the CDC reacted:

  • Walensky confirmed to CNN that the slideshow was presented to her at a noon briefing on Thursday. “I think people need to understand that we’re not crying wolf here. This is serious,” Walensky told CNN Thursday night. “It’s one of the most transmissible viruses we know about. Measles, chicken pox, this – they’re all up there," she said.
  • Walensky noted that the R0 for the Delta variant – a measure of its transmissibility – is estimated to be 5-9, meaning each infected person can be expected to infect 5-9 other people. “When you think about diseases that have an R0 of 8 or 9 – there aren’t that many.”
  • Asked about the contents of the slide deck, Walensky said, “There weren’t any surprises. It was the synthesis of the data all in one place that was sobering.”

What comes next:

  • The CDC is scheduled to publish additional data Friday that will back Walensky's controversial decision to change guidance for fully vaccinated people. She said Tuesday the CDC was recommending that even fully vaccinated people wear masks indoors in places where transmission of the virus is sustained or high.

CNN's Paul LeBlanc and Maggie Fox contributed reporting to this post.