PADUCAH — No vaccine in the world is 100% effective. The Center's for Disease Control and Prevention has tracked the efficacy rate of the flu vaccine since 2003 and report it's about 40 to 60% effective.

So why take it?

"So that we can reduce the number of deaths due to influenza," said Dr. Sarah Patrick an epidemiologist and public health expert at Southern Illinois University Carbondale. "It also reduces the number of hospitalizations which is really important right now during COVID because we know hospitals are getting very full due to COVID patients."

According to the CDC in the 2018-19 flu season, vaccinating only half of all Americans prevented 4.4 million cases of the flu, 58,000 hospitalizations, and 3,500 deaths. In that year that the vaccine was only 29% effective.

Early studies from Pfizer and Moderna show a COVID-19 vaccine could be up to 95% effective.

An efficacy rate in the 90s is similar to that of the chicken pox, small pox or measles vaccine. Before the measles vaccine in started in 1963 an estimated 3 to 4 million people got measles each year in the United States and about 400 to 500 people died. Now the CDC says since widespread use of measles vaccine there's been more than a 99% reduction in measles cases compared with the pre-vaccine era.

Medical historian Dr. Susan Lawrence said it takes years for health experts to get a population to herd immunity. 

"The thing with small pox was the reason it came back year after year after year, even with attempts to vaccinate the population," Lawrence said, a professor at the University of Tennessee at Knoxville. "Older populations grew up who had not been vaccinated or who refused to be vaccinated." 

The basis for a small pox vaccination began in 1796 with an English doctor named Edward Jenner. It took about two centuries after that for the disease to be eradicated.

"Something to keep in mind that just because we have a vaccine now doesn't mean it's going to convert herd immunity to eradicate this virus," Lawrence said. 

Both Patrick and Lawrence recommend everyone trust the experts and do the small things like wear a mask and wash your hands. This, in addition to a vaccine, can help the population reach herd immunity faster. 

"It's important to realize it's not just for you when you get vaccinated you actually help save other people as well," Patrick said.