Trials of experimental coronavirus vaccines are already under way, but it’s still likely to be years before one is ready and vaccination may not even be possible
Health
| Analysis
29 April 2020
By Carrie Arnold
Reuters/Joseph Campbell
MANY UK newspapers recently celebrated the first volunteer to receive an injection as part of a safety trial of an experimental coronavirus vaccine. But while there are claims that it could be possible for a vaccine to be ready within a year, the chances of this happening remain slim.
The UK trial, led by the University of Oxford, will ultimately involve 1100 adults, half of whom will receive the experimental vaccine. The other half will get a meningitis vaccine as a control. The team behind the trial hopes to move on to tests to gauge how effective the vaccine is against the coronavirus as early as August, raising hopes that a vaccine could be ready before the end of the year, and that this could be the answer to the difficult question of how the country gets out of strict social distancing measures.
Unfortunately, these hopes are probably misplaced. Vaccine design expert Maria Bottazzi of Baylor College of Medicine in Houston, Texas, calls the schedule “unrealistic”. Even if everything goes according to plan in the first phase of trials, Bottazzi points out that researchers will still need time to determine how well the vaccine protects people from covid-19 and whether it provokes any side effects when a vaccinated person is subsequently exposed to the virus.
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It is far from guaranteed that the vaccine will be safe and effective. 2013 study calculated that, before entering clinical trials, the average experimental vaccine has a 6 per cent chance of ultimately reaching the market. Of those that make it into trials, a 2019 analysis suggests the probability of success is 33.4 per cent.
But even if the Oxford vaccine succeeds, there will then be the issue of scaling up manufacturing to make hundreds of millions of doses. According to Bottazzi, this is the real bottleneck. Under the best of circumstances, the world is still looking at 12 to 18 months before a vaccine could be widely available, she says.
That in itself would be a remarkable achievement. The 2013 study found that between 1998 and 2009, the average time taken to develop a vaccine was 10.7 years. It is possible to speed this up to some extent – since then, an Ebola vaccine has become the fastest-developed vaccine ever, being produced in just five years.
But to lower this to just 18 months would require the next steps of the development process to be begun before the previous ones were completed, Bottazzi says. This increases the risk of significant loss of investment should the vaccine fail to pan out, as well as raising questions about safety. An expedited path from early trials to scaled-up manufacturing would mean that researchers won’t have as much time to study the long-term effects of a vaccine in trial participants before it is given to the public, for example.
“Between 1998 and 2009, the average time taken to develop a vaccine was 10.7 years”
To try to speed things up, on 21 April, UK health minister Matt Hancock said that the government will put money into manufacturing capability, in the hope that either the Oxford vaccine, or another vaccine being tested by Imperial College London, will prove successful. Similar measures are being taken elsewhere. US philanthropist Bill Gates has announced he is helping to build manufacturing capability for seven candidate vaccines – a strategy he said will lose billions of dollars but save time.
More than 100 vaccines for the coronavirus are currently in various early stages of development. The more that are tested, the higher the chances of finding something that is both safe and effective.
Yet there is no guarantee that it is even possible to vaccinate against the coronavirus. There is a lot we don’t know yet about how our immune systems respond to the virus, and whether it is possible to induce long-lasting immunity to it.
Hancock also said that the government is “throwing everything” at developing a coronavirus vaccine. But given the time it will take to get one – if it even proves possible to do so – it is clear that countries can’t wait for a vaccine to get them out of their current crises. As epidemiologist Mark Woolhouse at the University of Edinburgh, UK, told New Scientist in early April: “I do not think waiting for a vaccine should be dignified with the word ‘strategy’. It’s not a strategy, it’s a hope.”
We need to be realistic about the hopes of a vaccine, but that doesn’t mean it isn’t worth trying. Like annual flu vaccines, an effective coronavirus vaccine could help us protect those most at risk from the virus. As with childhood vaccines for measles and other diseases, it may also enable us to protect future generations from covid-19.
But it could be years before we have a vaccine. Until then, we will need to deal with multiple waves of infection with measures such as extensive testing, contact tracing and quarantining.
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