“We are not where we want to be in terms of genetic sequencing, although we are increasing,” said the government official. “We are starting far behind in genetic sequencing.”
To find new strains of the virus, scientists must genetically sequence samples – spelling the letters in their genetic code and looking for changes. Coronaviruses are known to mutate, usually in ways that are harmless to humans. But every now and then, a mutation appears that can change the way the virus works.
In the United States, scientists fear that the variants first identified in the United Kingdom, South Africa and Brazil may be more contagious, more likely to cause reinfection or somewhat resistant to existing Covid-19 vaccines.
The fear is that these variants could erase recent progress in reducing the number of Covid-19 cases. They can also increase the number of Americans who need to be vaccinated to obtain collective immunity.
An additional concern for the government that goes hand in hand with the spread of variants, the government official said, is coronavirus fatigue – and convincing Americans to continue practicing responsible public health behavior, such as wearing masks and social detachment. a year after the pandemic.
“It’s not exciting to say, ‘Wear a mask, keep your distance and get the vaccine when it’s your turn.’ But these are, in fact, the concrete steps that people can take to prevent this variant. This is the fastest way to prevent this variant, “said the official.” It is difficult. People are tired of it. I’m tired of this. Everyone is tired of living in their homes and not seeing their families and friends. “
In a meeting at the White House on Wednesday, the director of the US Center for Disease Control and Prevention, Dr. Rochelle Walensky, said the variant first detected in the UK is now responsible for about 1 to 4% cases in the country.
“We do not believe that the variants are evenly distributed across the country at this time,” she said. Walensky did not provide estimates for the other variants identified for the first time in South Africa and Brazil.
Last month, CDC modeling predicted that the UK variant, known as B.1.1.7, could become the dominant strain in the United States in March. The agency estimates that it is about 50% more transmissible than previous strains.
Experts say that South Africa and Brazil variants are more difficult to find than B.1.1.7, because the latter results in a failure in certain PCR tests – prompting scientists to take a closer look and preferentially sequence these samples. For other variants, it is usually a matter of random sampling.
“The South African variant has been recognized in some states with only a few people, but it is very likely more prevalent than that because we do not yet have the full surveillance sequence that we will be doing,” Dr. Anthony Fauci, Biden’s chief medical advisor, said at the meeting on Wednesday.
He added that this variant is “a little more problematic” for what appears to be a partial escape from antibody protection. However, he also pointed to more hopeful evidence that vaccines can offer “substantial protection” against serious illness, hospitalization and death.
The United States has stepped up its sequencing efforts and is on track to process at least 7,000 samples a week, Walensky said earlier. But she also repeated claims that more sequencing is needed to track the spread of variants across the country.
A CDC official previously told CNN that the UK and some other countries have a more centralized system for doing sequencing. But in the United States, several different types of labs – federal, state, academic and private – are doing the job.
Denmark, for example, launched an effort to sequence all positive samples from 12 January, a spokesman for the government’s public health institute told CNN last week. Before that, the institute, called the Statens Serum Institut, had fully sequenced about 20% of positive samples since the pandemic began.
Only eight states have genetically sequenced more than 1% of all coronavirus cases during the pandemic, compared with a national average of just under 0.4%, according to CDC data. Eighteen states have sequenced less than 0.1% of their confirmed cases.
Experts previously told CNN that the US should aim to sequence 5% to 10% of cases, in line with sequencing efforts in the UK. Given the cases of the past seven days, this would amount to about 38,000 to 76,000 strings in a week.