It was first spotted in Colorado at the end of December, said Fauci, the director of the National Institute of Allergy and Infectious Diseases and the chief medical adviser to President Biden.
“Since then it has been detected in 50 jurisdictions in the United States, and likely accounts now for about 20 to 30% of the infections in this country. And that number is growing,” Fauci said.
“Of concern is that there are about 50% increase in transmission with this particular variant that has been documented in the UK and there’s likely an increase in severity of disease if infected with this variant,” he said.
But vaccines appear to protect well against B.1.1.7 and treatments such as monoclonal antibodies also appear to work against this particular variant, Fauci said.
That makes it more important than ever to get people vaccinated quickly, he said.
“The way we can counter 1.1.7, which is a growing threat in our country, is to do two things: To get as many people vaccinated as quickly and as expeditiously as possible with the vaccine that we know works against this variant and, finally, to implement the public health measures that we talk about all the time … masking, physical distancing, and avoiding congregant settings, particularly indoors,” he said.
Vaccines appear to protect against B.1.1.7 variant
The three vaccines that have so far won emergency use authorization from the US Food and Drug Administration appear to protect people well against B.1.1.7.
There’s less evidence about the vaccine made by Johnson & Johnson’s Janssen vaccine arm, although it was tested in the US after B.1.1.7 started circulating.
Both BioNTech and Moderna have helped coordinate multiple tests of their vaccines against the variants.
Ugur Sahin of BioNTech and colleagues tested blood from 40 volunteers immunized with the Pfizer/BioNTech vaccine against lab-engineered versions of the B.1.1.7 variant.
Virus could acquire more mutations
What did worry them was if more mutations were acquired by the virus. Several variants are worrying doctors, including the B.1.351 variant first seen in South Africa and the P.1 variant that is common now in Brazil. Both carry a mutation known as E484K that does seem to significantly evade the body’s immune response.
“Worryingly, we have shown that there are multiple B.1.1.7 sequences in the UK bearing E484K with early evidence of transmission as well as independent acquisitions,” they wrote.
Several experiments indicate that the B.1.351 and P.1. variants may much more easily evade the immune response prompted by vaccines and also by some monoclonal antibody treatments, which deploy lab engineered immune system proteins to boost immune response.
Not as many experiments have been done using the more recently authorized Johnson & Johnson vaccine, but it was tested in the US after B.1.1.7 was starting to spread; in South Africa after B.1.351 was already the most common variant; and in Brazil after P.1 became widespread.
While it was less effective against moderate disease in South Africa and Brazil than in the US, it nonetheless strongly protected people against severe disease, hospitalizations and deaths in clinical trials.
Viruses mutate all the time, and a few of the mutations have taken hold in variants that have arisen in the US, notably in California and New York. The changes they carry include some of the changes that make the B.1.351 and P.1 variants so much more dangerous than B.1.1.7. So Fauci and the CDC say that makes it even more important to get as many people vaccinated as possible before those variants can spread.