Vaccines may be monovalent (also called univalent ) or multivalent (also called polyvalent ). A monovalent vaccine is designed to immunize against a single antigen or single microorganism.  A multivalent or polyvalent vaccine is designed to immunize against two or more strains of the same microorganism, or against two or more microorganisms.  The valency of a multivalent vaccine may be denoted with a Greek or Latin prefix (., tetravalent or quadrivalent ). In certain cases, a monovalent vaccine may be preferable for rapidly developing a strong immune response. 
How it works: According to Dr. Edwards, stress produces chemicals in the body that increase inflammation. “With relaxation techniques, you have stress reduction and therefore decreased inflammation and less pain,” she says. Meditation also relaxes muscles that tense up with pain. Dr. Edwards suggests meditating for 20 minutes once or twice a day. For moments of acute pain, she also recommends “meditation minutes.” For example, take four to five deep breaths, counting to 10 with each inhalation and exhalation. “Just doing that four to five times a day can decrease depression and improve outlook,” she says.