fill in the blanks with the suitable word from the box. words:vaccinate,problems,protect,disease,against,infected,curs.
Over the centuries,many doctors tried to find a .........for the disease but none succeeded. However,in1774,a doctor called Edward Jenner decided to investigate the belief that people who gad had cowpox could not be.........with smallpox. Cowpox was a much less serious..........and hardly ever caused any lasting............Jenner discovered what it was possible to............people from smallpox by giving them cowpox first,and he began to...............large numbers of people............the disease.
