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.
The polio (IPV) vaccine protects against the virus that causes poliomyelitis, commonly known as polio. It is a 4-shot series for children. What to know before your visit. Our practitioners provide the booster dose at 4â6 years. Patients must be 19 years or older in Connecticut, and 11 years or older in Kentucky.