Clinical trials of vaccines and drugsProtocols for clinical trials
Clinical trials of vaccines and drugs are carried out to show that they are safe and effective. Tests are randomised, use control groups given placebos, and are carried out double-blind to avoid bias.
All participants in the clinical trial are split into different groups entirely at random. A computer programme may be used. Randomising the participants reduces possible bias in the trial, for example by preventing people of the same gender or similar ages together.
Placebo-controlled
A placebo is a 'dummy' treatment with no medical or therapeutic value. A placebo looks like the drug being tested but only contains sugar.
One group of participants will be given the drug and another control group will be given the placebo. It is important that participants are not aware of which group they are in. Following the completion of the trial, results will be compared.
Double-blind
In a double-blind trial, neither the participants nor the researchers are aware which group has been given the drug and which group has been given the placebo. This also reduces bias when interpreting the results.