This is what I always wondered. Most placebo studies work with pain/chronic pain. But can you somehow use the Placebo effect to reduce the duration of the flu?

This is what I always wondered. Most placebo studies work with pain/chronic pain. But can you somehow use the Placebo effect to reduce the duration of the flu? Or other infections? Does a good patient-doctor relationship (article says that this is an important factor in Placebos) promote faster recovery when a virus is involved? Edit: Although even here, you often need to trust the answer of a patient about their well-being and can’t necessarily pinpoint the duration of the flu to measurable symptoms only.