And how do vaccines from the muscle "get into the immune system"? This is roughly the wording of the question we heard recently and so we thought this topic needed clarity! The answer is hidden in the animation☝🏻 The drug from the muscle gets into the bloodstream fairly quickly - you don't need more than that to trigger an immune response. Almost every point in the body has an extensive system of lymphatic vessels, which is also indicated in the animation. That means the immune response will also be quite fast! However, not all vaccines are injected into the muscle. Some vaccines, such as the rotavirus vaccine, are given orally. Others are given directly under the skin or subcutaneously - you might think of measles, mumps, and rubella vaccines. The essence is the same. The drug eventually enters the bloodstream in the same way, where the expected immune response occurs.