Dr Hopkins told the Science and Technology Committee said the current estimate of true daily infections is between 15,000 and 20,000 new infections.
She said: “What we are seeing at the moment are about 7,000 to 8,000 infections per day – that’s what we’re detecting.
“But we know that that is less than half of what the true infections are in the community, and we’ve measured that in a number of ways.
“So the estimate for current infections today is probably in the order of between 15,000 and 25,000 new infections today.”
Dr Hopkins added: “So that means that we do need to have some measures in place, both social responsibility measures and the measures that are in place right now, to try and hold that peak down so that we can get as much vaccine into the individuals to reduce symptomatic disease, reduce transmission, and then clearly severity and hospitalisation.”