Single jabs of Covid-19 vaccinations are providing 67% protection against infection, according to data from the Zoe Covid Symptom Study App.

Epidemiologist Professor Tim Spector of King’s College London, told Sky News’ Sophy Ridge on Sunday that the Government’s policy of delaying second jabs appeared to be working and restrictions should be able to begin to be reduced within weeks.

He said that Covid-19 cases had dropped by 80% since the start of January, with hospital admissions reducing by 60%, along with a 50% decrease of people in hospital with the virus.

Prof Spector said this showed the R rate had been “persistently” below one during this period.

He explained that a single vaccine was providing 46% protection after two weeks and 67% after three weeks.

He said: “It’s still preliminary, we are still analysing the results. It’s looking very promising and the Government’s approach of delaying the second shot in order to get more people vaccinated looks like it’s paying off.”

He continued: “It currently means we are in a similar state as we were in October and if we look at the trajectory at where we are going, in a couple of weeks we are going to be where we were in May or June.

“There will be a prevalence of symptomatic cases of less then one in 500 which in my view, we should be able to reduce some of the restrictions, and I am particularly concerned we get kids back to school for as long as possible because of the known long-term negative effects of that.”

Prof Spector said that he would be happy for schools in some regions, particularly rural areas, to return earlier than the proposed March 8 date and especially for younger children who pose “very little risk to themselves or others”.

He said that he could see face masks and other social distancing restrictions being required in some situations for the longer term.

He added: “It may not be compulsory but I am also an optimist that we are going to drive the levels of this virus very low.”

Prof Spector said he believed the number of officially recognised symptoms should be increased as the testing programme could now handle the extra demand.

He said that other common symptoms were headache, fatigue, sore throat and muscle pain.

Prof Spector said that he no longer watched the Government’s daily briefings as he felt the statistics were not presented in context, particularly the death rates.

He said: “It’s very sad people die of anything. Yesterday around 600 people died of Covid but on a normal day in February 1,500 people die of heart disease, strokes, cancer etc or the flu.

“This has got a lot of people extremely anxious and are petrified to leave their homes and may have problems coming out if we do not put those statistics into context.

“People are dying of Covid but people die of other things. I would like to see less fear-mongering.”