In an air-handling system that provides cooled air to occupants of a building, most of the air is returned from the space back to the air handler to be reused. This is called â¦ Return Air, or RA. However, some fresh air (called Outside Air, or OA) must be mixed in.
Polio is a viral infection that can cause permanent paralysis. The inactivated poliovirus vaccine (IPV) is usually given at ages 2 months, 4 months, 6â18 months, and 4â6 years. Though the oral poliovirus vaccine (OPV) is still used in many parts of the world, it has not been used in the United States since 2000.
Young infants are at greatest risk for these infections. Children over 7 months and under 5 years who missed the shot as infants will benefit from one or more of these shots. POLIO (IPV, the injectable polio vaccine, administered as a shot, or in a few cases, OPV, the oral polio vaccine, administered in the mouth). Polio is a common virus that causes fever, sore throat, nausea, headaches, diarrhea, stomachaches, and stiffness and weakness in the neck, back, and legs.