Secretary Harry Roque said that President Rodrigo Duterte prefers to be injected with COVID-19 vaccine in the buttocks. Research shows that intramuscular injection in the dorsogluteal muscles in the buttocks has potential risk of sciatic nerve injury.

According to, if the sciatic nerve gets damaged, lower back pain, muscle weakness, and reflex abnormalities, usually in the lower leg, can be experienced. And in another study, severe cases can paralysed the hamstring and all the muscle below the knee, resulting in flail numb foot.

Even so, injection in the buttocks remains an option in practice. For many years, the buttocks has been the most common site in vaccination not until it was associated with sciatic nerve injury, which occurs commonly in children, the elderly, and underweight patients.


The United States’ Center for Disease Control and Prevention (CDC) only recommends injection in the buttocks when large volume or multiple doses must be given such as immune globulin. And the area that should be selected is the upper, outer mass of the gluteus maximus, away from the central region of the buttocks, where sciatic nerve is nearly located.

The CDC also advised that injectable immunobiologics should be administered in areas where there are minimal opportunities for any injuries. Thus, currently, the anterolateral aspect of the upper thigh and the deltoid muscle of the upper arm are the preferred sites for routine intramuscular vaccine.

Source: Manila Bulletin (