When talking about the Moderna or Pfizer vaccine, you will often hear that it is “94% effective.” But what exactly does that mean? This article is going to explain the inner workings of the study conditions and how researchers came up with the 94% number.
Study conditions
The first thing that you should understand is that the gold-standard in the medical experiments is something known as a Randomized Double Blind Placebo Controlled trial otherwise known as RDBPC. The reason why this is the best model is because it controls variables tightly and leaves little room for bias. We are now going to explore each aspect individually.
Randomized
This one is pretty straightforward: it means that the sample is randomly selected to prevent any biases from interfering with the data.
Placebo Controlled
To understand what placebo controlled means, you first have to understand what a placebo is. A placebo is an inactive substance usually in the form of some sort of sugar that will not affect your body. By the same token, a placebo controlled study involves one group that receives the placebo and another group that receives the actual medication. Why do this though? The reason is something known as the “placebo effect.” This phenomenon is when a patient reports feeling better simply because they think that they are on medication. This has a real impact that can translate into physical results! To prevent this, researchers use placebo controlled trials to compare those who have received the placebo to those who have received the actual medication. This is often coupled with…
Double Blind
A study is double blinding when neither the physician nor the patient knows whether the medication is a placebo or the real thing. This is used in conjunction with a placebo controlled trial to reduce the chances of the placebo effect from occurring. Because the patients don’t know if they are receiving a placebo or the actual drug, the placebo effect is less likely to happen.
What does all this mean?
Now that we have a basic understanding of the study conditions, we can explore what the actual numbers means. The Moderna vaccine for example is said to be nearly 94% effective but how did they get that? Well, the trial was first a Placebo-controlled double blind study involving 30, 000 participants. The 30,000 subjects were then split equally into two groups: one group that got the placebo and one group that got the actual drug. The reason for this was outlined above: the researchers wanted to prevent the placebo effect, and by splitting the participants in half, they are able to compare the effects of the drugs to those who don’t have the drug. 95 people in the placebo group tested positive for COVID while only 5 of those in the vaccine group were positive. This indicates a 94% effective rate between the two groups. The researchers got this number by calculating the difference (85 cases) caused by the drug divided by the total number of those infected (90 cases) in order to get .944 which rounds to 94%.
Conclusion
Now that you know how the numbers are calculated, hopefully you can spread the word and educate others. Together, we can spread awareness of the science behind the COVID-19 effort.
