The increase in life expectancy over the last fifty years is linked to improvements in medical and other technologies. Write fou

Two claims support the assertion that Jenner is credited with initiating and promoting immunization practices:

1. Jenner's interest in cowpox's protective features started during his apprenticeship. It reveals that Edward Jenner engaged in methods to safeguard against diseases from his teenage years. He learned that farm workers who had been infected with cowpox had immunity to the smallpox outbreak prevalent in Europe at that time. This led him to develop a cowpox-based vaccine.
2. Jenner took initial measures to eliminate smallpox. He first tested his smallpox vaccine on a child in 1796, who did not contract the disease. To gain validation from authorities, he then vaccinated 22 additional individuals, achieving successful results.