Clinical Trials Explained – Breaking the Chain of Infection

TODAY the first phase of a trial for a covid-19 vaccine has been announced in Australia, which will begin in the coming weeks.

Elizabeth Flaherty, editor of Scone.com.au sat down with Steve Davis, who was a doctor in the Australian Defence Force for 28 years, to talk about the nature of clinical trials and the time frames involved to find a safe and effective vaccine.

Watch the video or read the information below:

Why does it take so long to produce a vaccine or medication and what is the process to go through a clinical trial?

It can take a long time from the initial concept of a vaccine or medication until the time it moves through to be approved for use, many years in most cases. 

It needs to go through a thorough testing process to make sure the medication or the vaccine is safe and effective.

Initially, it is designing a study, ethics committee approvals, looking at the participants being representative of the population. it will be used on, so including people of all ages, men and women a broad trial needs a broad range of participants.

A vaccine for covid-19 needs to be effective and safe across the whole community, so participants in the study need to broadly represent the whole population in terms of men and women of all ages.

Once you are assessing the vaccine, the first stage may be in vitro testing or animal testing to look at toxicity and safety  of the agent and if that is safe they will go onto human trials.

They start with a small sample of people to look at the effectiveness and safety in the human population, usually beginning with a very small dose and then determine what is the dose which is most effective and safe.

Side effects

They also look at the side effects it may cause. Any medication, any vaccine is going to have side effects.

When you are doing a clinical trial, they have to list every single ailment noted in any individual. So, if anyone has a headache during the trial, headache will be listed as a possible side effect. When you look at the list of side effects for a medication, it is often long, but they include any health conditions the participants may have experienced during the trial.

For example, if they find one percent of the participants have headaches during the trial, then it will be listed, but one percent of the population may have headaches without using the medication or vaccine, but everything must be listed. But if they find 90 percent of people experienced bad headaches, then that is something which needs to be known as a side effect to people using the medication or vaccine.

The Final Phase

Once it is established that it is effective and safe in a relatively small group, then they move onto a larger population to again monitor the safety and effectiveness, before giving it the final tick for use.

Animal trials

Covid-19 vaccines have been trialled using ferrets, because they have lung proteins similar to humans, but there are many differences between ferrets and humans and what may be effective in a ferret, may not translate to being effective in humans.

We see with lots of viruses that they don’t transmit across species and it’s the same with reactions with many medications or a vaccine may not be effective in humans.

Which is why the first phase is testing on animals, but the next and final phases are in humans.

Time frames

Sometimes clinical trials can take ten years from concept to approval. So getting a vaccine out in 12 to 18 months is very fast.

More videos: on Covid-19 and Breaking the Chain of Infection.