उत्तर : 2. "जैमे फेरान"
व्याख्या :

1. The credit for developing the cholera vaccine in 1885 goes to Spanish-French bacteriologist and hygienist Jaime Ferrán.

2. He tested a live attenuated bacterial vaccine during a cholera epidemic in Valencia.

3. Jaime Ferrán's vaccine successfully protected people from cholera and began to be used in vaccination programs around the world.