Understanding Placebos in Clinical Trials

Clinical trials are intended to test the safety and effectiveness on investigational therapies. So why are placebos used, particularly in vaccine trials?

Placebos are particularly useful for helping researchers assess safety, efficacy, and actual side effects among control and treatment groups. What is a placebo though?

Placeboes are inactive pills, injections, or procedures that have no effect on humans. Placebos are commonly called ‘sugar pills’ or ‘saline shots’.

Placebos are used in some clinical trials to help researchers determine if an investigational therapy is effective. In a placebo-controlled trial, a control group receives a placebo, while a treatment group (a.k.a., experimental group) receives the treatment being studied.

Results from the control group and treatment group are then compared to determine the actual effect an investigational treatment causes.

In placebo-controlled studies, participants are usually blinded (a.k.a, masked), which means they don’t know whether they’re receiving a placebo or the investigational treatment.

In double-blind, placebo-controlled clinical trials, neither participants, or the clinical staff know who is receiving the placebo, or the investigational treatment.

Beyond helping researchers compare a control group to a treatment group, placebos and blinding can reduce the amount of bias in studies, especially for studies in which outcomes may be subjective (e.g., migraines, pain).

As part of the informed consent process, you’ll always know if you could receive a placebo as part of a clinical trial at Meridian.