Polio vaccine is usually provided in vials containing 10–20 doses of vaccine. A single dose of oral polio vaccine (usually two drops) contains 1,000,000 infectious units of Sabin 1 (effective against PV1), 100,000 infectious units of the Sabin 2 strain, and 600,000 infectious units of Sabin 3. The vaccine contains small traces of antibiotics—neomycin and streptomycin—but does not contain preservatives. In a generic sense, vaccination works by priming the immune system with an 'immunogen'. Stimulating immune response, by use of an infectious agent, is known as immunization. The development of immunity to polio efficiently blocks person-to-person transmission of wild poliovirus, thereby protecting
For the Term of His Natural Life not stop treating him like an inferior, at one point upsetting Dawes so much that he considers leaving on his own. Only Sylvia's writing in the sand, "Good Mr. Dawes", stops him. Through a hazard, Frere tells Dawes of the fate of his cousin and how narrowly he missed inheriting the Devine fortune. Dawes had not known about Sir Richard's death. Finally, they set to sea with Mrs. Vickers gravely ill and Sylvia soon also sick. After some time they are found by an American vessel at which point Frere takes the rudder of the boat and Sylvia in his