This may offer a new incentive to lose weight...it turns out people who are obese may not be getting the most out of vaccines or any injection, if it is given in the hip.
Researchers told a meeting of the Radiological Society that when people are overweight, especially heavy in the rear. The amount of fat tissue over the muscles in that area is greater than the length of the needles commonly used. So, they're not getting the dosage they need because it can't reach the muscle where it is absorbed into the blood stream.
They suggest one way to fix the problem, longer needles for obese patients.