Rangarira ndima iri pasi apa uye ipapo pindura mubvunzo gare gare mumutauro mumwe chetewo sechikamu:  Passage: Mushonga wokutanga wokudzivirira polio wakabudirira wakagadzirwa muna 1952 naJonas Salk neboka repaUniversity of Pittsburgh raisanganisira Julius Youngner, Byron Bennett, L. James Lewis, naLorraine Friedman, izvo zvaida makore okuedzwa kwakatevera. Salk akaenda panhepfenyuro yeCBS kunoshuma kuedza kwakabudirira paboka duku revakuru nevana pana 26 March 1953; mazuva maviri gare gare, migumisiro yacho yakabudiswa muJAMA. Kutanga musi wa 23 February 1954, mushonga uyu wakaedzwa paArsenal Elementary School uye paWatson Home for Children muPittsburgh, Pennsylvania. Mushonga waSalk wakazoshandiswa muedzo wainzi Francis Field Trial, wakatungamirirwa naThomas Francis, kuedza kukuru kwezvokurapa munhoroondo panguva iyoyo. Muedzo wacho wakatanga nevana vanenge 4.000 paFranklin Sherman Elementary School muMcLean, Virginia, uye pakupedzisira wakabatanidza vana vane mamiriyoni 1,8, vari mumatunhu 44 kubva kuMaine kusvika kuCalifornia. Pakupera kwechidzidzo chacho, vanenge 440 000 vakagamuchira jekiseni rimwe chete kana kuti anopfuura emushonga wacho, vana vanenge 210 000 vakagamuchira chinonzi placebo, chinoumbwa nemishonga isingakuvadzi, uye vana vane mamiriyoni 1,2 havana kubayiwa nhomba uye vakashanda seboka rokudzora, avo vaizocherechedzwa kuti vaone kana mumwe wavo akabatwa neporiyo.  Mubvunzo: Pakupedzisira, vana vangani vose zvavo vakapinda mukuedza?
Vana vane mamiriyoni 1,8