A mixture: 1  can be separated into 2 or more substances by physical or mechanical means. 2  displays the properties of the pure substances making it up. 3  its composition can be varied by changing the proportion of pure substances making it up.  heterogeneous substances, ones with non-uniform composition throughout the sample, are always mixtures.
Injection Site Symptoms. At least half of all people who receive pneumonia shots will experience mild side effects in the area of injection, such as pain or redness. Less commonly, swelling or hardness may also occur in the area. These symptoms can limit movement of the arm or leg where the shot was given.
Vaccine Side Effects. Most people donât have any serious side effects from vaccines. The most common side effects â like soreness where the shot was given â are usually mild and go away quickly on their own. What are common side effects of vaccines? The most common side effects after vaccination are mild. They include: Pain, swelling, or redness where the shot was given; Mild fever; Chills; Feeling tired; Headache; Muscle and joint aches