On 26 March 1953, Dr. Jonas Salk announced that he had successfully tested a vaccine to prevent polio, clinical trials began the next year.
Polio occurs naturally only in humans. It is highly infectious, and is spread from person to person either through fecal-oral transmission (e.g. poor hygiene, or by ingestion of food or water contaminated by human feces), or via the oral-oral route. Those who are infected may spread the disease for up to six weeks even if no symptoms are present. The disease may be diagnosed by finding the virus in the feces or detecting antibodies against it in the blood.
No comments:
Post a Comment