A successful vaccine for Covid-19 will not conquer the spread of the virus alone, with restrictions on daily life likely to continue for some time, a team of experts have said.
Hundreds of teams of researchers around the world are working to produce a vaccine against the coronavirus, with 11 currently in phase three human trials. The UK government has reserved access to six potential vaccines and has raised hopes that a vaccine could be on the cards by spring next year.
A report from a multidisciplinary group convened by the Royal Society, called Delve (Data Evaluation and Learning for Viral Epidemics), says there are serious challenges to producing a vaccine, including hurdles in manufacturing and storage, questions around how well vaccines will work, and problems with public trust.
Prof Nilay Shah, the head of the department of chemical engineering at Imperial College London, and an author of the report, said that while there would be vaccines available in March – not least because manufacturing is beginning before the results of trials are known– the question was whether they will have been shown to be effective and passed regulatory processes.
“Even if we get through that and the material is available and 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,” he said, adding that it may take up to a year.
Prof Charles Bangham, the chair of immunology at Imperial College London and a co-author of the report, said: “Even if it is effective, it is very unlikely that we will be able to get back completely to normal. There is going to be a sliding scale even after the introduction of a vaccine that we know to be effective. We will have to gradually relax some of the other interventions.”
Bangham said few vaccines completely block an infection, but they can reduce both the severity of disease and the chance of passing it on. However, in the case of vaccines in development against Covid, myriad questions remain.
Concerns have already been raised that vaccines against Covid may be less effective in older adults than in other groups – a potential issue if supplies are limited and vaccinations have to be prioritised to those most at risk from becoming infected.
The team says a policy of vaccinating widely in an attempt to produce herd immunity could also run into potential difficulties, particularly if the vaccine has limited effectiveness. And for any mass vaccination programme, there are manufacturing and supply hurdles to overcome.
“We need to make sure that [we are going to have] all the ingredients for these tens of millions of doses in the UK, and several billions globally,” said Shah, noting that these range from chemicals to glass vials, while some may need to be kept at extremely low temperatures.
A vaccination programme would need to carried out at about 10 times the pace of seasonal flu vaccinations, said Shah. “That would need many thousands of individual healthcare workers, retrained people, dedicated solely to delivering vaccinations,” he said.
Public trust in a vaccine may also present a hurdle. Dr Zania Stamataki, a researcher in viral immunology at the University of Birmingham, said: “By the time the first vaccines are released, we need to do our best to dispel any myths surrounding vaccination and reassure individuals and families that they are safe, tested properly and that no corners have been cut in their preparation at all regarding safety.”