Vaccine trials explained, and how this relates to covid 19

Today we tackle the hot topic that everyone is discussing: a vaccine for covid 19.

Covid 19 vaccine

Of course, it goes without saying that without clinical trials, a vaccine would be impossible altogether.  But many people have asked why the vaccine will take so long.  There are many different factors at work here, so we will do our best to touch on a few of them, and hopefully make it clearer how vaccine trials differ from therapeutic trials, and why they take longer.

Firstly, you need healthy volunteers for a vaccine trial (i.e. people without covid 19).  It can be more difficult to recruit healthy patients, as they may be less motivated to be exposed to a medicine which may or may not have side effects, for a condition that they are currently not suffering from.

The second is an ethical issue.  When conducting a clinical trial, you cannot put patients at unnecessary risk.  This means that you cannot intentionally expose a person to Sars-CoV-2 after giving them your trial vaccine (which may or may not work).  You would need to encourage your trial participants to follow the same guidelines that the rest of the population is following (in this case, social distancing, hand-washing, etc).  Then you monitor these patients for a length of time to see if covid 19 occurs less frequently in them than in people who did not receive your trial vaccine.  This take time.

Thirdly, in order to ensure that your vaccine doesn’t have rare or long-term side effects, you need to give it to a very large number of people.  Think in the region of tens of thousands.  Some vaccines that we currently have on the market were tested in 70,000 patients before being deemed safe.

Fourthly, medications that are made using living organisms like our covid 19 vaccine would need to be (also called biologics) are much more complicated to work with.  They require extra man-power, extremely highly qualified scientists, and very specialised facilities and equipment.  Incredibly strict quality control measures are undertaken at every step of the process.

So, how long does this all take?  Typically, it can take in the region of 15-20 years to create a safe and effective vaccine.  If you are really quick and all the stars align in your favour, perhaps you may get one in 10-12 years.  One of our rotavirus vaccines that is currently widely used took 26 years to create and test.

Check out this great short video to explain vaccine trials in a nutshell:

Now, we have all heard in the media that a covid 19 vaccine may be ready in 18-24 months.  How does this fit in with the time frames described above?  Well, to put it simply, it would be impossible without skipping some of the usual steps.  Scientists will need to walk a very fine line between safety and speed, and certainly won’t know all of the rare or long terms side effects before the vaccine is made available so fast.  They would need to weigh the risks of giving a vaccine which hasn’t been fully tested to people, with the potential benefits of preventing covid 19 infection.

On the bright side, and in spite of all these challenges, there are currently at least 90 potential COVID-19 vaccines under study, and six of those are already being tested on humans in clinical trials to determine if they’re safe.  The following article gives a little bit more detail about that, and the early promise they are showing:

If you have time for a slightly longer video, where a few different issues surrounding Sars-CoV-2 and the vaccine are dealt with in a bit more detail by leading experts, we can recommend this one:

We hope that this has answered some of your questions surrounding vaccine clinical trials, and in particular the vaccine for covid 19.  Please feel free to reach out to us if you would like to chat more.