Delta variant is ‘Covid-19 on steroids,’ expert says, with cases increasing in nearly half of US states

Twenty-four states have seen an uptick of at least 10% in Covid-19 cases over the past week, Johns Hopkins University data shows, as health experts and the federal government keep pressing for more people to get vaccinated.

The rapid spread of the Delta variant of the coronavirus has only ratcheted up the pressure.

That variant, first identified in India, accounted for 51.7% of all new Covid-19 infections in the country over the two weeks that ended Saturday, the US Centers for Disease Control and Prevention has estimated.

“We should think about the Delta variant as the 2020 version of Covid-19 on steroids,” Andy Slavitt, a former senior adviser to Joe Biden’s Covid Response Team, told CNN on Wednesday. “It’s twice as infectious. Fortunately, unlike 2020, we actually have a tool that stops the Delta variant in its tracks: It’s called vaccine.”

Burial of Covid-19 victims at Inhauma Cemetery, in Rio de Janeiro, Brazil, on June 25, 2021.

Related article Global Covid-19 death toll surpasses 4 million

For fully vaccinated people, the variant “presents very little threat to you, very unlikely that you’re gonna get sick,” he said

Full approval for vaccines from the US Food and Drug Administration could encourage more people to get vaccinated, Slavitt and other experts have said. The current vaccines distributed in the US are authorized for emergency use only. Full approval for the Pfizer vaccine could come as early as this month, Slavitt said Tuesday.

On Thursday, Pfizer said it was seeing waning immunity from its vaccine. The company is now picking up its efforts to develop a booster dose that will protect people from variants.

“Based on the totality of the data they have to date, Pfizer and BioNTech believe that a third dose may be beneficial within 6 to 12 months following the second dose to maintain highest levels of protection,” the company said in a statement emailed to CNN.

The company said booster doses of its vaccine, developed with BioNTech, produce levels of neutralizing antibodies that are five to 10 times higher than what’s produced after two doses. And it added that it’s also developing a new formulation for a booster dose that may protect people from new variants more thoroughly.

A Pfizer spokesperson later told CNN the company planned to file for emergency use authorization for a booster dose with the FDA in August.

Cases and hospitalizations are up, CDC chief says

As of Thursday, less than half of the US population – 47.7% – was fully vaccinated. The percentage of eligible people who were fully vaccinated – ages 12 and up – was 55.8%.

Cases and hospitalizations are up especially in parts of the country where vaccination coverage is low, CDC Director Dr. Rochelle Walensky said at a White House Covid-19 briefing Thursday.

Counties with the highest case rates tended to have low vaccination rates. In the last week, 173 counties had at least 100 cases per 100,000 residents – and in more than 90% of those counties, vaccination coverage was less than 40%, Walensky said.

“Many of these counties are also the same locations where the Delta variant represents the large majority of circulating virus,” Walensky said.

“Low vaccination rates in these counties, coupled with high case rates – and lax mitigation policies that do not protect those who are unvaccinated from disease – will certainly, and sadly, lead to more unnecessary suffering, hospitalizations and potentially deaths,” she added.

The case rate has been rising for the US as a whole. The country averaged more than 15,060 new cases a day over a week ending Wednesday –20.7% higher than the average from the week prior, according to Johns Hopkins data.

The average is still well below this spring’s peak – an average of 71,320 daily for a week ending April 14 – and the pandemic peak average of more than 251,000 daily for a week ending January 8.

Covid-19 hospitalizations also have been ticking up recently. The number of Covid-19 patients in US hospitals was nearly 18,000 Tuesday, according to the US Department of Health and Human Services.

That’s slightly above the total of 16,792 two weeks earlier, though well below the pandemic peak of more than 136,000 on January 5.

Wearing face masks, people walk last month through Union Station in Los Angeles. California is one of the 24 states seeing an uptick in Covid-19 cases.

California positivity rate triples

In California, where state data shows the Delta variant has been identified in roughly 43% of new sequenced specimens, the Covid-19 test positivity rate has tripled in the weeks since the state fully reopened.

The positivity rate has climbed past 2% for the first time since early March, after dropping to an all-time low of just 0.7% in early June.

So far, the influx in infections hasn’t immediately been reflected in a spike in hospitalizations or deaths – but officials warn those effects tend to lag behind by a couple of weeks.

Roughly 60% of people statewide have been fully vaccinated against Covid-19, state data shows, while more than 9% are partially vaccinated.

5 largest undervaccinated clusters largely in the South

A new data analysis has identified clusters of unvaccinated people, most of them in the southern United States, that are vulnerable to surges in cases and could become breeding grounds for even more deadly Covid-19 variants.

Related article 5 undervaccinated clusters put the entire United States at risk

The analysis by researchers at Georgetown University identified 30 clusters of counties with low vaccination rates and significant population sizes. The five most significant of those clusters are sprawled across large swaths of the southeastern United States and a smaller portion in the Midwest.

The five clusters are largely in parts of eight states, starting in the east in Georgia and stretching west to Texas and north to southern Missouri. The clusters include parts of Alabama, Arkansas, Louisiana, Oklahoma and Tennessee, and are made up of mostly smaller counties but also cities such as Montgomery, Alabama; Shreveport, Louisiana; and Amarillo, Texas.

Most of these states are currently seeing increases in Covid-19 cases.

“Parts of the country are just as vulnerable if not more vulnerable than they were in December 2020,” said Shweta Bansal, an associate professor of biology at Georgetown University. Bansal heads up the US COVID-19 Vaccination Tracking project, which has been gathering data on the US vaccine rollout since it began in December.

Vaccinations saved hundreds of thousands of lives in US, researchers say

In a grim reminder of the scale of the pandemic, the global death toll from Covid-19 has reached more than 4 million, data from Johns Hopkins on Wednesday showed.

Three countries account for more than a third of all global deaths. The US, which has the highest number of fatalities at 606,000, accounts for 15% of the global total, followed by Brazil and India.

Underscoring vaccines’ effectiveness, researchers say the American toll would have been a lot worse without inoculations.

The US would have seen about 279,000 more Covid-19 deaths by June 28 had vaccinations – which first became available in December – not have taken place, according to researchers at Yale University and the Commonwealth Fund. The country also would have seen as many as 1.25 million additional hospitalizations, the researchers said.

Fears about more variants if people don’t get vaccinated

The Delta variant is not the only one worrying health experts.

“Right now, you want to look at who’s getting sick, whether from the Delta variant or any other variant: It’s people who haven’t been vaccinated,” Dr. Megan Ranney told CNN on Wednesday.

“I don’t want it to come to this, but I am hopeful that these surges will drive more people in those states with low vaccination rates to finally go out and get their shot.”

Vaccinated people don’t have much to worry about, said Ranney, an emergency physician at Rhode Island Hospital and an associate professor at Brown University.

But she offered an unsettling insight on the current surge of cases.

“What worries me more are the variants yet to come. And every time this virus is passed from one person to another, it has a chance to mutate. And it’s only a matter of time until we have a variant against which the vaccines no longer protect us,” she explained.

Some experts have begun asking whether it may be time to start testing vaccinated people to ensure the Delta variant does not evade the effects of vaccines.

A man receives a nasal swab COVID-19 test at Tom Bradley International Terminal at Los Angeles International Airport (LAX) amid a coronavirus surge in Southern California on December 22, 2020 in Los Angeles, California.

Related article With Delta variant spreading, experts split on whether to test vaccinated people for Covid-19

Current federal guidelines say fully vaccinated people can refrain from routine testing. Studies and experts have also said the vaccines are still highly protective.

“I think now we should revisit this policy with the Delta variant and determine if the current recommendations hold up,” Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, wrote in an email to CNN on Wednesday.

The CDC is only reporting data on “breakthrough” infections that cause severe disease. That could mean scientists and health officials will not know how many vaccinated people have mild or asymptomatic infections – and it will be very difficult to track whether a new variant such as Delta is causing more vaccine failure.

CNN’s Deidre McPhillips, Maggie Fox, Jason Hanna, Jacqueline Howard, Keri Enriquez, Virginia Langmaid, Elizabeth Cohen, John Bonifield and Hannah Sarisohn contributed to this report.