The vaccination of the UK population against Covid-19 may take more than a year, experts have warned, due to a series of “bottlenecks” that could slow the nationwide rollout.
If a vaccine becomes available by the end of 2020 or early next year, it’s unlikely life will immediately return to normal, according to Professor Nilay Shah, head of chemical engineering at Imperial College London.
He added that although the clinical trials for many of the vaccine candidates are being fast-tracked, they will still have to go through all the regulatory checks.
Eleven vaccines are currently in the final phase three trial, with the Oxford University and Moderna candidates leading the way, but the logistics involved in rolling out billions of doses across the world are expected to present a number of challenges.
This includes the difficulty of storing and transporting vaccine doses at the correct temperature - some shots will require cold storage of -80C - and administering shots to entire populations.
Prof Shah, who is one of the authors of a new Royal Society report on vaccine development and implementation, told reporters at a media briefing: “Even when the vaccine is available, it doesn't mean within a month that everyone is going to be vaccinated.
“You're talking about six, nine months, a year. What's interesting about that is how long can you let that stretch out, especially if these things need to be administered periodically, because we don't know how long the immune response will last.”
He said that as the UK increases its capacity once a vaccine is approved, administration will have to be “balanced with the prioritisation of different groups - whether that's vulnerable groups, health workers and then age cohorts”.
Addressing concerns that the countries may not have access to enough glass vials, to store doses, or refrigerated lorries, to transport the vaccine, Prof Shah acknowledged “that there will be a bit of a scramble for some of these input ingredients and resources”.
He added that the UK could need “somewhere between” 10,000 and 30,000 professionals “who are purely dedicated every working day to vaccinating people”.
“There will be bottlenecks [in the supply chain] but I think people are beginning to start to think about the whole system and where the investments need to be,” he said. “It will take some time to roll out the vaccinations even when they're approved.”
Professor Charles Bangham, who is chairman of immunology at Imperial College London and co-author of the Royal Society's Delve (Data Evaluation and Learning for Viral Epidemics) report, said the return to normal would have to be on a "sliding scale" with a "gradual relaxing" of some of the restrictions.
He said it was "reasonable" to expect that an effective vaccine would "give immunity that would last more than one year".
Prof Shah said the vaccination programme for Covid-19 would need to have a high uptake to be effective - around "10 times the rate at which we vaccinate peak influenza vaccinations in the late autumn".
Prof Bangham added: "It is possible that, in the future, it will be necessary to re-vaccinate, just as we do with influenza."
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."
The Delve report comes as the European Medicines Agency (EMA), the continent’s main health regulator for medical drugs, announced that it had started a rolling review of the Oxford University vaccine.
The start of the review means that the EMA’s vaccine committee has begun evaluating the first batch of data on the candidate. This process of analysis will continue until sufficient data is available and a formal application is made.
“This does not mean that a conclusion can be reached yet on the vaccine’s safety and effectiveness, as much of the evidence is still to be submitted to the committee,” the watchdog said.
The Oxford University team behind the vaccine said it welcomed the EMA’s announcement.
“A rolling review is one of the tools that the EMA uses to speed up the assessment of a promising medicine or vaccine during a public health emergency,” a spokesperson said.
This process has previously been used by the EMA in the assessment of Remdesivir as a Covid-19 therapeutic medicine.
Early-stage data in July showed the Oxford vaccine elicited immune responses in clinical trials and produced no serious side effects, with the strongest response seen in people who received two doses. Data on late-stage trials are expected soon.