The anti-measles vaccine was invented in several stages. The measles virus was first discovered in 196 1 year. When measles virus was successfully isolated, people realized that measles virus was very harmful to human body. So two years later, 1963, the United States began to successfully produce anti-measles vaccine with chicken embryo amniotic membrane and monolayer cells.
When measles infected people have close contact with measles susceptible people, the incidence rate can reach more than 95%, and the age of measles is between/kloc-0 and 5 years old, accounting for 80% of the total incidence rate. Therefore, many infants and young children will suffer from measles after the anti-measles vaccine has not been developed, which eventually leads to a high child mortality rate. In the past, measles vaccine was popular every few years, so people learned it.
In the 1960s, a professor at the University of Pennsylvania began to study this virus. Although this virus can be very harmful in human body, it can't be cultivated in the laboratory. A few years later, they finally cultivated the cell line of this vaccine and multiplied many cells. They successfully developed a vaccine against measles virus by using proliferating cells. Salk and Sabin, as well as France's L'Epine, have made great contributions to this vaccine, and it is they who can develop measles vaccine and treat children's measles well.
The above story only represents my personal opinion. Please forgive me if there is any mistake.