Explanation

in the early 1950s, the first successful vaccine was created by US physician Jonas Salk.

Salk tested his experimental killed-virus vaccine on himself and his family in 1953

First used Salk vaccine in 1955 ( in activated)

while 

A live attenuated (weakened) oral polio vaccine developed by Dr. Albert Sabin and first used in 1961.

Israel launched a polio vaccine drive after 1988 in April 2022

Explanation

French physicists Charles Fabry and Henri Buisson discovered the ozone layer in 1913.

They used an interferometer to measure the amount of ozone in the atmosphere.

Explanation

Edward Jenner (1749-1823) was an English physician and scientist who discovered the smallpox vaccine in 1796.

He observed that milkmaids who had contracted cowpox, a similar virus, were immune to smallpox.

Explanation

Ronald Ross was a medical doctor who received the Nobel Prize for Physiology or Medicine in 1902 for his work on the transmission of malaria.

He belonged to the British.

Explanation

Joseph Priestly discovered oxygen on August 1, 1774.

The most abundant element in the Earth's crust is oxygen.

It making up 46.6% of Earth's mass.