In the past few days, the media has been talking non-stop about AstraZeneca halting the clinical trials for one of the most promising COVID-19 vaccines. Although this scared people and caused turmoil, it is not unusual for clinical trials to be temporarily discontinued. After only 5 days, the trial has resumed, as the investigation conducted by AstraZeneca deemed the vaccine safe for further testing. In this article, I will briefly discuss the steps of clinical trials leading to Phase 3 and my thoughts on the way the media is reporting on the Oxford vaccine.
A brief outline of clinical trials
In one of my previous articles, What I Think About Animal Research, I briefly explained how a drug-or in this case a vaccine-goes through a series of steps before reaching clinical trials. Researchers must go through a strict protocol, which not only is subjected to general regulation but also specific rules depending on the molecule tested.
Cancer Research UK explains how clinical trials in humans work. Starting from just a few individuals (Phases 0 and 1), the number of patients increases exponentially for Phase 3, where thousands of subjects are needed. The AstraZeneca vaccine is at this step, testing in Countries were the number of COVID-19 cases is still high.
Here is a Phase 3 protocol for a drug aimed at patients suffering from migraine. Although the document is long and complex, I encourage you to have a look at it and pause on Sections 7 and 8, where the criteria for discontinuation and the possible adverse reactions are listed. As you can read, these criteria are strict and detailed; researchers need to record them beforehand and from the earlier phases in the trial, so they already know when the drug is reacting as expected and up to when the drug is safe to administer.
I’ll use an example to simplify this concept. If a patient experiences headache for a drug that has never given it to other subjects, researchers need to stop the trial until this symptom is investigated. Keep in mind the reaction needed to stop a trial must be threatening the subject’s wellbeing. For the AstraZeneca trial, the patient developed transverse myelitis, an inflammatory syndrome caused by viral infections and that affects the spinal cord, according to The New York Times.
As of today, investigators have ruled the vaccine safe to continue the trials, i.e. the subject’s reaction was not caused by the vaccine itself. But why is it fundamental to know how clinical trials work?
What is the media telling us about it?
Watching the news in the past few days, I realised how much disinformation is circulating around the Oxford vaccine. I guess it’s not something new, as I have been seeing crazy theories and “biological explanations” about the virus since January. However, given the situation we will be in for the foreseeable future, I think spreading correct information is key.
It’s not that every outlet has shared fake news, but even the most reliable of them failed to convey the most important message: What happened with the Oxford vaccine is completely normal. Clinical trials are stopped often and for a variety of reasons. The example I shared earlier can help you grasp the number of likely explanations to why a trial is halted.
As I talked about in my article What I Think About Animal Research, the body is still a puzzle. One molecule can interact with hundreds of other molecules, causing reactions that can vary from individual to individual. It is not unexpected that one person will have an adverse reaction, which can depend on a series of factors that have nothing to do with the drug tested.
I have been repeating this in almost every article: Check your resources. If you see something popping up on the screen and you have questions about it, do your own research, keeping in mind who is sharing the information, what is their purpose and how updated the information is.
With regard to the COVID-19 vaccine, one reliable resource is the University of Oxford website, where you can find the latest news about the vaccine and how the trial is going ahead. The AstraZeneca website can give you additional information, not only about the COVID-19 vaccine, but also the latest on therapeutics in different areas, such as Oncology, Cardiovascular, Renal and Metabolic diseases.
When I was writing this article, I thought about how to make this information available to people with a different knowledge of biology and pharmacology. I hope I cleared things up for those with questions about how clinical trials work. As always, the links I left in the article are extra resources you can use to deepen your understanding of the subject, so I encourage you to follow them and read more about this.