Children have been warned not to hug their grandparents until the government is "absolutely sure" about the impact of the coronavirus vaccine rollout.
Dr Jenny Harries, deputy chief medical officer for England said a "steady course" needs to be taken through the roadmap out of lockdown.
Speaking at tonight's Downing Street press conference Dr Harries said: "The testing programme in schools is clearly going to mean that people, parents, grandparents and teachers and other schoolchildren, can be very assured schools will be as safe as they can be because we are trying to remove infection from that environment.
"And of course, that will have a really positive impact on breaking chains of transmission in communities and in those families.
"But the slight caveat to that is, having got so far down the line with this and now on the roadmap, very, very carefully coming out, I would encourage children not to go off yet, even if their grandparents have had their vaccinations.
"Not to go hugging them too much until we're absolutely sure what the impact of that vaccine rollout has been.
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"I'm sure it's going to be positive but we just need to take a steady course through the roadmap."
Dr Harries also said the rise of the Kent variant of Covid-19 meant it was right to take "additional precautions" by extending the use of face coverings in schools.
Dr Harries said: "Face coverings are there to help others - we are protecting others by wearing them.
"There are a number of different conditions at the moment.
"For example, we have a new variant, and while we are understanding that more, then obviously taking additional precautions makes sense.
"We understand more about the ability for aerosol generation and transmission, so that is also important.
"So things, I think, have moved on and it should be reassuring to know that we look at the evidence and then adjust our advice accordingly."
