The CDC warned House lawmakers that the delta variant, widespread across the country, is as contagious as chickenpox, has a longer transmission window than the original Covid-19 strain, and can make the elderly sicker even if fully vaccinated.
Thursday’s warning came in a confidential document that was reviewed by CNBC and authenticated by the federal health authority.
Delta, now in at least 132 countries and already the predominant form of the disease in the United States, is more commonly communicable than the common cold, 1918 Spanish flu, smallpox, Ebola, MERS and SARS, according to the document. Only measles seem to spread faster than the variant.
“The war has changed,” wrote officials from the Centers for Disease Control and Prevention.
Health officials said leaders should communicate the benefits of vaccination to the public.
Vaccines prevent more than 90% of serious illnesses, but they can be less effective at preventing infection, they said, making it more likely to spread to the community among those vaccinated. The document states that 162 million Americans vaccinated have 35,000 symptomatic infections per week.
Separately, the CDC has announced that by July 19, 5,914 fully vaccinated people had been hospitalized or died of Covid infections, the latest data available. Breakthrough cases that occur in those who are fully vaccinated are more common in crowds and groups at risk of primary vaccination failure, according to the document.
Health officials also said leaders should consider vaccine mandates, especially for health workers, universal masking and other community containment strategies. President Joe Biden announced Thursday that his administration would require federal workers to provide evidence of vaccination status or to undergo a series of strict safety protocols.
The documents presented to lawmakers came two days after the CDC reversed its previous course and advised fully vaccinated Americans living in areas with high rates of Covid infection to return to wearing face masks indoors. According to a CNBC analysis, the guidelines cover about two-thirds of the US population.
Dr. Paul Offit, who advises the FDA on Covid vaccines, said Friday it was “deeply” shocking that the US failed to vaccinate a critical segment of the population, adding that Delta had “changed the game”. About half of the US population is fully vaccinated, according to CDC data.
“Yesterday you had 90,000 cases and nearly 400 deaths,” Offit said. “Those are the same numbers you saw last summer. I mean, last summer you had a completely vulnerable population and you didn’t have a vaccine.”
He said the CDC documents underscore how “frustrated” federal officials are with the existence of safe and effective vaccines.
“The war is no longer against the virus. It is also a war against ourselves,” he said.
People infected with the Delta variant carry up to 1,000 times more viruses in their nasal passages than other strains, which, according to the federal health authorities, leads to a higher degree of transmission even among those who have been vaccinated. The CDC found that studies in Canada, Singapore, and Scotland found higher chances of hospitalization, ICU admission, oxygen needs, pneumonia, or death in people infected with the Delta variant.
While the variant that has emerged in India continues to hit unvaccinated people the hardest, some vaccinated people could carry higher amounts of the virus than previously thought and potentially pass it on to others, said CDC director Dr. Rochelle Walensky on Tuesday. She added that the variant “behaves uniquely differently from previous virus strains”.
“This pandemic continues to pose a serious threat to the health of all Americans,” Walensky told reporters on a call.
Rep. James E. Clyburn, DS.C., chairman of the Select Subcommittee on the Coronavirus Crisis, said Walensky and White House chief medical officer Dr. Anthony Fauci, informed the committee about the new dates on Thursday.
“I am deeply concerned about the rapidly increasing rates of coronavirus infection in the states of the country that are being powered by the Delta variant,” said Clyburn in a statement, noting that the Covid cases have been in the past two weeks and Hospital stays have increased by 145% and deaths are rising again, especially in areas with low vaccination rates. “This sudden turn of events threatens to undermine the significant strides we have made this year in overcoming the pandemic.”
– CNBC’s Rich Mendez, Robert Towey and Nate Rattner contributed to this report.
Download the full CDC presentation here.