Since March of 2020, over 29 million Americans have been diagnosed with COVID-19, according to the CDC. Over 540,000 have died in the United States as this unprecedented pandemic has swept the globe. And yet, by the end of 2020, it looked like science was winning: vaccines had been developed.

In celebration of the power of science we spoke to three people: an individual, a medical provider, and a vaccine scientist about how vaccines have impacted them throughout their lives. Here are their answers:

John Scully, 79, resident of Florida

Photo courtesy of John Scully

When John Scully was born, America was in the midst of an epidemic: tens of thousands of children in the United States were falling ill with paralytic poliomyelitis — otherwise known as polio, a disease that attacks the central nervous system and often leaves its victims partially or fully paralyzed.

"As kids, we were all afraid of getting polio," he says, "because if you got polio, you could end up in the dreaded iron lung and we were all terrified of those." Iron lungs were respirators that enclosed most of a person's body; people with severe cases often would end up in these respirators as they fought for their lives.

John remembers going to see matinee showings of cowboy movies on Saturdays and, before the movie, shorts would run. "Usually they showed the news," he says, "but I just remember seeing this one clip warning us about polio and it just showed all these kids in iron lungs." If kids survived the iron lung, they'd often come back to school on crutches, in leg braces, or in wheelchairs.

"We all tried to be really careful in the summer — or, as we called it back then, 'polio season,''" John says. This was because every year around Memorial Day, major outbreaks would begin to emerge and they'd spike sometime around August. People weren't really sure how the disease spread at the time, but many believed it traveled through the water. There was no cure — and every child was susceptible to getting sick with it.

"We couldn't swim in hot weather," he remembers, "and the municipal outdoor pool would close down in August."

Then, in 1954 clinical trials began for Dr. Jonas Salk's vaccine against polio and within a year, his vaccine was announced safe. "I got that vaccine at school," John says. Within two years, U.S. polio cases had dropped 85-95 percent — even before a second vaccine was developed by Dr. Albert Sabin in the 1960s. "I remember how much better things got after the vaccines came out. They changed everything," John says.