The CDC warned House lawmakers Thursday that the new delta variant sweeping across the country is as contagious as chickenpox, has a longer transmission window than the original Covid-19 strain and may make older people sicker, even if they’ve been fully vaccinated, according to a copy of the document reviewed by CNBC and authenticated by the U.S. agency.
Delta, now in at least 132 countries and already the dominant form of the disease in the United States, is more transmissible than the common cold, the 1918 Spanish flu, smallpox, Ebola, and MERS and SARS, two diseases also caused by coronaviruses, according to the document. Only measles appears to spread faster than the variant.
“The war has changed,” CDC officials wrote.
Health officials said federal and state leaders should communicate to the public the benefits of getting vaccinated, adding the Covid vaccine shots reduce the risk of severe disease and death “10-fold or greater” and reduce the risk of infection “3-fold.”
They also said federal and state leaders should consider vaccine mandates, particularly for health-care workers, universal masking and other community mitigation strategies. President Joe Biden announced on Thursday his administration would require federal workers to prove their vaccination status or submit to a series of rigorous safety protocols.
The documents, presented to lawmakers, came two days after the Centers for Disease Control and Prevention reversed course on its prior guidance and recommended fully vaccinated Americans who live in areas with high Covid infection rates resume wearing face masks indoors. The guidelines cover about two-thirds of the U.S. population, according to a CNBC analysis.
While the delta variant continues to hit unvaccinated people the hardest, some vaccinated people could be carrying higher levels of the virus than previously understood and are potentially transmitting it to others, CDC Director Dr. Rochelle Walensky said Tuesday. She added the variant behaves “uniquely differently from past strains of the virus.”
Rep. James E. Clyburn, chairman of the Select Subcommittee on the Coronavirus Crisis, said CDC Director Dr. Rochelle Walensky and White House chief medical advisor Dr. Anthony Fauci briefed the committee on the new data Thursday.
“I am deeply concerned about the rapidly increasing rates of coronavirus infections in states around the country that is being driven by the Delta variant,” Clyburn said in a statement, noting that Covid cases have increased by 145% in the last two weeks and hospitalizations and deaths are rising again, particularly in areas with low vaccination rates. “This sudden turn of events threatens to undermine the significant progress we have made this year to overcome the pandemic.”
