Answer:
it was only 90 percent effective
Explanation:
In 1954 a massive controlled field trial was launched, sponsored by the National Foundation for Infantile Paralysis. Almost two million U.S. children between the ages of six and nine participated. In some areas of the country half of these “Polio Pioneers” received the vaccine, while half received a placebo. In other areas of the country children who did not receive any vaccine were carefully observed. On April 12, 1955, Thomas Francis, Salk’s mentor and the director of the trial, reported that the vaccine was safe, potent, and 90% effective in protecting against paralytic poliomyelitis.
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among five spheres of the Earth, carbon (C) sinks: the biosphere, pedosphere, lithosphere, hydrosphere, and atmosphere (These are not mutually exclusive, see Glossary).
The vestibulocerebellum helps regulate balance and eye movement. Moreover, the spinocerebellum helps regulate body and limb movement and the cerebrocerebellum helps regulate in planning movements.
The vestibulocerebellum is a region of the cerebellum which involved in balance and body position in space.
The spinocerebellum is involved in controlling lateral descending systems in order to regulate distal limb muscles.
The cerebrocerebellum is involved in motor planning by connecting the motor and premotor cortices.
Learn more about the cerebellum here:
brainly.com/question/763962
Any factor or trait or condition that can exist
