The director of the Centers for Disease Control and Prevention (CDC) warned that coronavirus variants could set the U.S. back on the road to recovery.
Testifying on Tuesday before the Senate Health, Education, Labor and Pensions Committee on national efforts to address the COVID-19 pandemic, Dr Rochelle Walensky said she was happy to see case rates going down, but warned Americans to keep following prevention measures.
'We must remain diligent and committed to our surveillance and prevention efforts because the emergent of variants could set us back,' she said in her opening statement.
It comes as COVID-19 mutations continue to spread throughout the country - accounting for nearly three-quarters of all infections- with the UK variant now making up two-thirds of cases.
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CDC Director Dr Rochelle Walensky warned on Tuesday (above) that 'variants could set us back' of Americans don't stay vigilant and follow prevention measures
The CDC is sequencing about 10% of all samples per week, which revealed 72% of all U.S. cases are linked to the UK variant and 6% to the Brazilian variant (above)
Walensky testified later on in the hearing that the CDC and its partners, state and local public health laboratories, are sequencing about 10 percent of all samples per week.
The most recent results, as of Monday, show 72 percent of all cases in the U.S. are now linked to the UK variant and six percent to the Brazilian variant.
The UK variant was first discovered in the county of Kent in September but was not deemed a 'Variant of Concern' (VOC) until December.
Most estimates put it at about 70 percent more infectious than older 'wild-type' coronavirus variants.
More moderate projections say its transmissibility is only about 56 percent higher.
Officials in the UK says that variant may be 30 to 40 percent more deadly, and so far there have been two deaths in the U.S. linked to the variant.
Meanwhile, the Brazilian variant first caught international attention when four travelers arriving to Tokyo from Manaus, Brazil, tested positive on January 2.
The variant has the same spike protein mutation as the highly transmissible versions found in Kent and South Africa – named N501Y – which makes the spike better able to bind to receptors inside the body.
A recent study found the P.1 variant made up 42 percent of specimens taken from Manaus, the larger city on the Amazon.
This is notable because about 75 percent of the resident had already been infected with COVID-19 by October 2020.
Because the region experienced a devastating surge in cases, this suggests that P.1. is more transmissible.
However, its effect on transmissibility and/or virulence is currently unknown.
Currently, the CDC classifies coronavirus variants in three categories: variant of interest, variant of concern and variant of high consequence.
A variant that first emerged in India,B.1.617; the New York variant, B.1.526; and a less common UK variant, B.1.525, are classified 'variants of interest.'
There are four variants of concern - B.1.1.7; P.1; the South African variant, B.1.351; the and the California variant, B.1.427/B.1.429 - in the U.S. and no variants of consequence.
Walensky suggested one way to curb variants is with vaccinations, and even appeared to suggest kids lobby their parents for the shot after the Pfizer-BioNTech Covid shot was approved for emergency use for children aged 12 to 15.
'I recognize some parents want to see how it goes, but I am encouraging all children to be vaccinated,' she said during the hearing.
'And I am also encouraging children to ask for the vaccine. I have a 16-year-old and I continue he wanted to get the vaccine. He wants his life back.'
At the hearing, Dr David Kessler, COVID response Chief Scientific Officer for the Department of Health and Human Services (HHS), revealed the U.S. is laying the groundwork to make doses of boosters available in the fall if needed.
'We are planning, and I underscore the word planning, to have boosters available if necessary for the American people,' he said.
'Increased age and that natural warning of antibodies over time and new variants increase the probability that boosters may be needed.'