It’s the question on everyone’s lips: when will we have a coronavirus vaccine? A vaccine seems to be the key to returning to normality, but the answer as to when we will have one remains uncertain.
As of August 2020, there were 166 Covid-19 vaccines in various stages of development. They all face one big challenge before they can be mass manufactured: human clinical trials. In June, the University of Oxford announced that it was ready to begin these trials, however the national lockdown meant the vaccine could not be tested on the UK population.
To understand why, we have to look at the process of vaccine development. Any new drug or vaccine is first tested on human cells or animals. It then moves into 3 phases of human trials, the third of which is the lengthiest and requires thousands of people. Volunteers are randomly given a vaccine or a placebo (a substance designed to have no effect) and are encouraged to get on with their everyday lives. Scientists wait for months or even years to see who falls ill. However, everyday life at the moment is riddled with Covid-19 prevention methods, such as wearing masks and bans on household mixing, and therefore the true effectiveness of any vaccine cannot be accurately measured. Oxford University had to move their trials to areas of high infection rates such as South Africa and Brazil.
The whole development process can take up to 10 years, but those developing the Covid-19 vaccine are aiming to reduce this to one and a half. This could be done in a variety of ways, from overlapping phases, to manufacturing whilst the trials are still taking place. Of the 166 vaccines in development, 24 are conducting human trials and 5 of them are in the lengthy phase 3. There is one bold method, however, that could shorten these trials or even replace phase 3 altogether.
Human challenge trials work by healthy individuals volunteering to be injected with the virus and then the trial vaccine. This saved typhoid vaccine researchers 3 to 4 years; it could save Covid-19 five months. On 23rd September, Imperial College London announced that it would be the first to conduct these trials in January 2021.
There is one thing that makes the Covid-19 challenge trial different and potentially more dangerous than any of its predecessors. At the moment we do not have an effective ‘back-up’ treatment for coronavirus. This means that volunteers could be putting their lives at risk if they take part in the study.
So, is it ethical to deliberately inject a human with a potentially fatal virus? In May 2020, the World Health Organisation decided yes, stating that the “potential benefits of SARS-CoV-2 challenge studies outweigh risks.” It’s a classic “the needs of the many outweigh the needs of the few” situation; and the risk seems to be worthwhile to volunteers. Over 38,000 individuals from 166 countries have signed up to be part of human challenge trials.
One particular group makes up the majority of these volunteers. Data from the Office for National Statistics shows that deaths of people aged 15-44 from Covid-19 account for only 1% of the UK’s total coronavirus deaths since December last year. The 90 volunteers of the Imperial College study all come from within this age range, dramatically reducing the likelihood of a death during the trials.
Again, this throws up its own problems regarding sample size and the use of a narrow age-range of people. We won’t know if the vaccine is safe and effective for the wider population. However, an imperfect vaccine is better than no vaccine at all and this is something that, as a society, we seem to be willing to accept.
By Catherine Upex
Since this article was published, news has broken of a new potential vaccine. More information to follow!
Header image: Arek Socha/Pixabay