The flu vaccine changes every year. The flu vaccine is based on a predicted strain that is anticipated to be the most infectious that year. Thats why people who sometimes get the vaccination still get the flu, they don't have the antibodies for the strain they were infected with. Strains for viral disease don't change very much and usually the vaccination for them cover them well.
Answer:
<em>Hi Tadashi Here! </em>
Explanation:
Skin has three layers: The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone. The dermis, beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands. The deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue.
<em>~Your Welcome Friend! :)</em>