S.NAGENDRA / SCIENCE PHOTO LIBRARY S.NAGENDRA / SCIENCE PHOTO LIBRARY
A nurse administering an oral vaccine against poliomyelitis (polio) to an infant in India. Polio is an infectious viral disease affecting the central nervous system. In severe cases polio may cause paralysis. It is most often associated with poor sanitation, as the virus is excreted in the faeces of the infected person. The oral vaccine is a live attenuated type: the virus is cultured under special conditions such that it loses its virulence but retains its ability to stimulate antibody production. Oral polio vaccines are also known as Sabin strains, and are given in three doses in infancy. Further vaccination is suggested at school entry and later.
Model release not available. Property release not required.