The U.K. variant is known as B.1.1.7 or 20I/501Y.V1.
This variant emerged with an unusual large number of mutations.
The spread of this variant greatly affected a surge of COVID-19 cases in UK since November, 2021.
Importantly, this variant spreads more easily and quickly than other previously known variants. Indeed, the variant has shown 30-50% enhanced transmissibility compared to initially emerged SARS-CoV-2.
This variant is now spreading globally (at least 41 different countries).
N501Y mutation in the receptor-binding domain (RBD) of spike protein can enhance its affinity to the human ACE2 receptor (a major impact on fast spread of the variant).
P681H mutation could potentially affect cell infectivity and replication of virus.
A new variant has emerged from the “UK variant”; the “Bristol variant”, contains the E484K mutation (potentially favoring evasion form the immune response) also found in the “South African and Brazilian” variants
There is so far no strong evidence for an enhanced lethality due to this variant.
However, the UK Heath Authority has recently reported that this variant may be associated with an increased risk of death compared to other variant viruses. Yet, this needs to be confirmed by fine epidemiological studies.
Several Vaccine-producing companies (Pfizer-BioNTech, Moderna, AstraZeneca-Oxford, Johnson and Johnson, Novavax) have confirmed that their vaccines, based on different designs, can all be effective against this variant.
As an example, the Novavax vaccine has shown an efficacy of 89.3% in its Phase 3 clinical trial conducted in the UK.
Only a handful of studies have addressed this point; so far the available evidence suggests that this variant should not affect the efficacy of currently available therapeutics, such as monoclonal antibody-based therapy.
The current molecular tests detect most of the variants and thus are able to diagnose COVID-19 infection by such variants. Yet, the fine identification of the type of variants is still based on sequence analysis although multiplex PCR test are being evaluated.
Indeed, the current variants of concern show distinctive mutations in the spike protein. Due to such mutations, most diagnostic tests for COVID-19 have been designed by targeting not only the spike protein but also other conserved proteins. For example, molecular tests designed to detect multiple SARS-CoV-2 genes (i.e., multiplex reverse transcription polymerase chain reaction targeting ORF1ab, N, and E genes) are less susceptible to the effects of genetic variation than tests designed to detect a single gene. The FDA is also monitoring the potential effects of genetic variation in molecular tests that have received Emergency Use Authorization, and provides information about the tests.
Overall, the precise characterization of the variants still relies on genomic sequencing analysis. For instance, CDC is currently increasing sequence surveillance to more than 6000 samples per week to efficiently monitor the variants of concerns and other emerging variants. Information on where COVID-19 caused by variants in the U.S. can be found here.