Does the US have a new fast-spreading and highly infectious Covid-19 variant? Here’s what the CDC has to say
Reports that there may be a very contagious and fast-spreading coronavirus variant in the US were published by multiple media outlets on January 8. A White House document claimed that a possible new US variant, in addition to the UK strain, maybe 50% more transmissible and is already spreading in communities.
The White House report, however, does not identify a specific new strain nor confirm that one has been detected in the US. Rather, it suggests that the possibility of a new strain could potentially explain the rapid acceleration in cases in recent months.
“This fall/winter surge has been at nearly twice the rate of rise of cases as the spring and summer surges. This acceleration suggests there may be a US variant that has evolved here, in addition to the UK variant that is already spreading in our communities and maybe 50% more transmissible,” stated the White House task force document, dated January 3, 2021, which was sent to states.
According to the task force, while data reporting has been unstable for the past week, hospital reporting has been stable and the US remains at a high plateau of 140-150,000 confirmed and suspected Covid-19 admissions per week and 120-125,000 total inpatients. “Significant continued deterioration, from California across the Sunbelt and up into the Southeast, Mid-Atlantic, and Northeast, despite low testing rates during the holidays, suggests aggressive community spread,” it warns.
The document was also posted online by the state of Kentucky, which shows that White House officials advised more stringent mitigation measures to halt a potentially more transmissible virus. “Aggressive mitigation must be used to match a more aggressive virus; without uniform implementation of effective face masking (two or three ply and well-fitting) and strict social distancing, epidemics could quickly worsen as these variants spread and become predominant,” it recommended.
The US Centers for Disease Control and Prevention (CDC), has, however, emphasized that it had not seen the emergence of a new US variant of the coronavirus. It added that there may be many variants of Covid-19 across the world.
“Researchers at the CDC are monitoring all emerging variants of the coronavirus, including in 5,700 samples collected in November and December. To date, neither researchers nor analysts at CDC have seen the emergence of a particular variant in the US,” noted Jason McDonald, a spokesman for the CDC, according to a New York Times (NYT) report.
The NYT article also suggests that the task force hypothesis was the result of speculation by Dr Deborah Birx, the White Housecoronavirus coordinator, and said that the CDC had urged her not to include the speculation in the document. “CDC officials did not agree with her assessment and asked to remove it but were told no, according to one frustrated CDC official, speaking on condition of anonymity for fear of retaliation,” it adds.
According to another report, if such a variant exists, it would take weeks or months for it to be detected. “It could (take) weeks or months to identify if there is a single variant of the virus that causes Covid-19, fueling the surge in the US similar to the surge in the UK,” the CDC told Yahoo Finance.
What is a variant?
Viruses constantly change through mutation, and new variants of a virus are expected to occur over time. Sometimes new variants emerge and disappear. Other times, new variants emerge and persist.
The virus that causes Covid-19 is a type of coronavirus, a large family of viruses. Coronaviruses are named for the crown-like spikes on their surfaces. Scientists monitor changes in the virus, including changes to the spikes on the surface of the virus. These studies, including genetic analyses of the virus, are helping us understand how changes to the virus might affect how it spreads and what happens to people who are infected with it.
What variants are currently circulating?
Multiple variants of the virus that causes Covid-19 are circulating globally, have been documented in the US and globally during this pandemic. In the UK, a new variant (known as 20B/501Y.V1, VOC 202012/01, or B.1.1.7 lineage) has emerged with an unusually large number of mutations. This variant seems to spread more easily and quickly than other variants. Currently, there is no evidence that it causes more severe illness or increased risk of death. This variant was first detected in September 2020 and is now highly prevalent in London and southeast England. It has since been detected in numerous countries around the world, including the US and Canada.
The US is currently tracking cases of the UK variant. The CDC has identified over 60 coronavirus cases with the B.1.1.7 mutation in the US.
In South Africa, another variant of SARS-CoV-2 (known as 20C/501Y.V2 or B.1.351 lineage) emerged independently of the B.1.1.7 lineage. This variant shares some mutations with the B.1.1.7 lineage. Cases attributed to this variant have been detected outside of South Africa.
Scientists are working to learn more about these variants, and more studies are needed to understand how widely these new variants have spread, how the new variants differ, and how the disease caused by these new variants differs from the disease caused by other variants that are currently circulating. A new study from Pfizer found that its vaccine developed with BioNTech appeared to be effective against the key mutation in the UK strain as well as the variant found in South Africa.
The CDC, in collaboration with other public health agencies, is monitoring the situation closely. “CDC has been conducting SARS-CoV-2 Strain Surveillance to build a collection of SARS-CoV-2 specimens and sequences to support public health response. Routine analysis of the available genetic sequence data will enable CDC and its public health partners to identify variant viruses for further characterization,” explains the agency.