Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention.
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New and highly contagious variants of the coronavirus are a “threat” to the United States and could reverse the recent drop in Covid-19 cases and hospitalizations, the head of the Centers for Disease Control and Prevention warned on Monday.
The United States reported a seven-day average of 119,900 new Covid-19 cases per day last week, down almost 20% from the previous week, but still “dramatically greater” than the peak seen during the summer, said the CDC director Dr. Rochelle Walensky told reporters during a press conference at the White House on Covid-19.
The country also reported an average of 9,977 hospitalizations for Covid-19 a day last week, a drop of at least 17% from the previous week, she said.
“The continued proliferation of variants remains a major concern and is a threat that could reverse the recent positive trends that we are seeing,” said Walensky. “Please continue to wear a mask and stand 2 meters away from people you don’t live with. Avoid travel, crowds and poorly ventilated spaces and be vaccinated when it is available to you, ”she added.
US health officials, including Dr. Anthony Fauci, have expressed concerns about Covid mutations that could escape the protection of vaccines currently on the market. Moderna, Johnson & Johnson and Novavax have said that their vaccines may be less potent against B.1.351, the highly contagious strain found in South Africa.
On Sunday, South African Health Minister Zweli Mkhize said the country would suspend the use of AstraZeneca’s Covid-19 vaccine in its vaccination program after data showed that it provided minimal protection against B.1.351, the emerging strain there. He said the government would await advice from scientists on how best to proceed after the disappointing results of a test conducted by the University of Witwatersrand.
As of Sunday, the CDC had identified 690 cases of variant B.1.1.7 first identified in the UK, Walensky told reporters on Monday. The agency identified six cases of the South African strain, as well as three cases of P.1, a variant first identified in travelers from Brazil.
Walensky said public health officials are working to find more cases of these variants, adding that federal and state authorities in the past three weeks have increased genome sequencing by about ten times. “We are predicting that we can find more cases” in the coming weeks, she added.
The United States is always working to find out just how contagious and deadly the new strains are, said Fauci, the country’s leading infectious disease specialist.
UK Prime Minister Boris Johnson said last month that the first figures suggest that the country’s tension could be more deadly. Fauci said on Monday that there is no data to indicate that the virus is turning into a “less virulent” strain, which means less harmful than the original virus.
The UK data still “needs to be confirmed,” added Fauci. “But so far, there is no evidence that it is less virulent. Sometimes, when viruses mutate to spread more efficiently, they become less virulent, but we have no data to indicate that this is actually happening.”
Meanwhile, Fauci is pushing for people to be vaccinated as soon as possible, saying last week that the virus cannot mutate unless it infects its hosts and replicates.