Coronavirus Information and Resources

New Variant Coronavirus Strain FAQs

Last revised 12/23/20


A new variant strain of SARS-CoV-2 that contains a series of mutations has been reported in the United Kingdom. It is widespread in London and southeast England accounting for about 60% of infections in London.

While SARS-CoV-2 has been mutating since it was discovered, acquiring about one new mutation in its genome every two weeks, a research study reports this variant has 8 mutations in the spike protein gene and 17 in all. What's unusual is the number of mutations in this strain. There appears to be a jump from the steady mutation rate we have had so far. 

This variant has a mutation in the receptor binding domain of the spike protein. It may bind more tightly to the angiotensin-converting enzyme 2 (ACE2) receptor, which is how the virus gains entry into cells. Based on these mutations, this variant strain has been predicted to potentially be more contagious than other circulating strains of SARS-CoV-2. Officials in the UK have said it can be up to 70% more infectious.

There is currently no evidence that this new variant produces more severe illness than other SARS-CoV-2 variants. It is early days, though, and data are being collected and analyzed to accurately assess its impact.

Most commercial polymerase chain reaction (PCR) tests have multiple targets to detect the virus, so even if a mutation affects one of the targets, the other PCR targets will still work.

The mutations could potentially decrease the effectiveness of monoclonal antibodies in treating the virus, however, that is unknown at this time.

The available vaccines cover multiple parts of the Spike protein and would not be impacted by few changes in it. The virus would likely need to accumulate multiple mutations in the spike protein to evade immunity induced by vaccines or by natural infection. If enough changes accumulated to impact the effectiveness of vaccines, it would be relatively straightforward to adapt the vaccines to the new variants, as we do routinely with flu vaccines.

This new variant has not been identified through sequencing efforts in the United States, although viruses have only been sequenced from a small fraction of the US cases. Ongoing travel between the United Kingdom and the United States, as well as the high prevalence of this variant among current UK infections, increase the likelihood. The variant could already be in the United States without having been detected.

The same measures that protect against other SARS-CoV-2 strains are effective against the new variant – properly wearing masks everywhere but outside of your home; maintaining physical distance; frequent handwashing; staying home when you’re sick; avoiding gatherings with people outside of your immediate family or pod.