During the mid 19th century, England was swept with three severe waves of contagious diseases. Over half of deaths in England during this time were attributed to infection. This gave rise to the Vaccination Act which gave offered free vaccination to anyone, including the poor who needed it most. This set in motion several more health reforms and vaccination laws.

Source: 

Diniejko, Andrzej. A Chronology of Social Change and Social Reform in Great Britain in the Nineteenth and Early Twentieth Centuries, 2014, www.victorianweb.org/history/socialism/chronology.html.