Maria Van Kerkhove, the Covid-19 technical lead at the World Health Organization, also appeared on the show.
She said the variant had also been identified in Denmark, the Netherlands and Australia – with there being one case in the latter that did not spread further.
She added: “And so more sequencing that can be done will be helpful to help us determine if this variant is circulating elsewhere. Sequencing will also help us understand any changes in the viruses that are being identified.
“The longer this virus spreads, the more opportunities it has to change. So we really need to do everything we can right now to prevent spread, and minimising that spread will reduce the chances of it changing.”
Dr Hopkins, meanwhile, said that the evidence that the new variant was up to 70 per cent more transmissible was based on modelling the rate of increase in the new strain compared with others in circulation.
She added: “We have seen evidence of the virus showing higher viral loads so there’s more virus in the people we are detecting with this virus strain.”
But she said a higher viral load did not mean people were going to get more ill, adding: “The illness comes from the immune response and how it reacts in your lungs – that’s where we know the illness really starts to be driven from and why people need oxygen.
“The higher amount of the virus means that people are likely to be more infectious than they would otherwise be and this means we need to reiterate the social distancing measures.”
The great escape
Dr Hopkins said that the main routes of transmission of the new variant were the same as the previous strains.
She said the Tier 4 measures and shorter Christmas bubble announced on Saturday by Boris Johnson were “really important”, adding: “This virus will not transmit unless we are in contact with each other and really close contact, indoor spaces, reduced ventilation all help drive the transmission of this virus, no matter what variant it is.”