Live in the UK may not return to normal until Easter 2021, Government scientist Jonathan Van Tam has warned.
It came as new daily infections from coronavirus crept up again.
The Office for National Statistics estimated there were 3,800 new infections a day in the week ending August 9.
This is up from 3,700 a day the previous week and was published as Government scientists announced the R reproductive number “may be increasing”.
Professor Van warned the public to follow the rules until a vaccine could become effective.
“I don’t think the use of vaccines will provide a meaningful ‘public health result’ until about Easter,” he said.
“After that I’m hoping that their impact will be substantial.
“I’d hope that spring 2021 will represent a new dawn for the country, by which time we’ll be able to live life fairly safely.
“Even so, moving forward, the way we live will change.
“Covid-19 won’t be eradicated anytime soon and we’ll have to learn to live with it to some extent.
“Maybe working from home will become far more common over the longer term in some industries.”
The Scientific Advisory Group for Emergencies (SAGE) published its latest R range showing it remained between 0.8 and 1 for the UK.
However it warned this is based on factors including deaths and hospital admissions which can take a few weeks to show up in the data.
The ONS surveillance testing of 20,000 people revealed new infections had surged by 50% in the week up to July 26 before dropping slightly in the week ending August 2.
Katherine Kent, head of the ONS Covid-19 Infection Survey, said: “This week’s estimate suggests that the increase in infections in England seen in July has now levelled off.
“Regional analysis of antibody data for England, published for the first time this week, show that a higher percentage of people in London have ever tested positive for antibodies to the virus than in Yorkshire and the Humber, the East Midlands, the South East and the South West.”
Another Covid-19 spike could have big implications for the country with children due to return to schools in a few weeks.
The R number is the average number of people infected by each Covid-19 case.
A separate “growth rate” measures the percentage that the UK outbreak is shrinking each day.
This was published at between -5% and 0%, with the upper end of the estimate suggesting it may have stopped shrinking.
It had been -4% to -1% the previous week.
Sage said in a statement: “We are starting to see early indications that these values may be increasing.
“This is not yet fully reflected in these estimates because the data used to calculate R and growth rate reflect the situation from a few weeks ago.”
Dr Yuliya Kyrychko, mathematician at Sussex University, said: “The situation is pretty much on the precipice, and the it can develop very rapidly, which means that all possible caution should be taken by the public.”
