Experts have said it could take more than a year for everyone in the UK to get a Covid vaccine, should one become available.
Clinical trials for many of the vaccine candidates are currently being fast-tracked but they will still have to demonstrate a protective effect against the virus and go through regulatory checks before being rolled out.
Professor Nilay Shah, head of the department of chemical engineering at Imperial College London, said if a vaccine becomes available in early spring, it does not mean life will be “returning to normal in March”.
Prof Shah, one of the authors of a Royal Society report on vaccine development and implementation, said: “(Even if) vaccination does start in the spring, it will take a long time to work through the different priority groups initially, and then the wider population later on.
“We may be able to start the process but then to get through that vaccination process, it (will take) many months, maybe more than a year.”
Professor Charles Bangham, chairman of immunology at Imperial College London, said the return to normal would have to be on a “sliding scale” with a “gradual relaxing” of some of the restrictions.
The report’s co-author said it was “reasonable” to expect that an effective vaccine would “give immunity that would last more than one year”.
He added: “It is possible that, in the future, it will be necessary to re-vaccinate, just as we do with influenza.”
The report discusses the scenarios, options and challenges involved in developing, manufacturing and distributing Covid-19 vaccines.
Dr Fiona Culley, of the National Heart and Lung Institute at Imperial College London and one of the lead authors of the report, said: “Vaccines are held up as our best chance of getting our lives back to some sense of normality, but we have to be realistic.
“Planning now for the different scenarios that might play out will give us the best chance of taking rapid advantage of any vaccines that are proven to be safe and effective.”
There are more than 200 vaccine candidates being developed around the world, with more than 40 in clinical trials, nine of which are in the phase three stage.
The UK has secured access to six different Covid-19 vaccine candidates in development, across four different types, representing more than 340 million doses.
Priority groups such as the elderly, frontline health and care home workers and those with serious diseases are first in line to receive a jab, should a vaccine be approved.